1
|
Meng QL, Qiang CG, Li JL, Geng MF, Ren NN, Cai Z, Wang MX, Jiao ZH, Zhang FM, Song XJ, Ge S. Genetic architecture of ecological divergence between Oryza rufipogon and Oryza nivara. Mol Ecol 2024; 33:e17268. [PMID: 38230514 DOI: 10.1111/mec.17268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/18/2024]
Abstract
Ecological divergence due to habitat difference plays a prominent role in the formation of new species, but the genetic architecture during ecological speciation and the mechanism underlying phenotypic divergence remain less understood. Two wild ancestors of rice (Oryza rufipogon and Oryza nivara) are a progenitor-derivative species pair with ecological divergence and provide a unique system for studying ecological adaptation/speciation. Here, we constructed a high-resolution linkage map and conducted a quantitative trait locus (QTL) analysis of 19 phenotypic traits using an F2 population generated from a cross between the two Oryza species. We identified 113 QTLs associated with interspecific divergence of 16 quantitative traits, with effect sizes ranging from 1.61% to 34.1% in terms of the percentage of variation explained (PVE). The distribution of effect sizes of QTLs followed a negative exponential, suggesting that a few genes of large effect and many genes of small effect were responsible for the phenotypic divergence. We observed 18 clusters of QTLs (QTL hotspots) on 11 chromosomes, significantly more than that expected by chance, demonstrating the importance of coinheritance of loci/genes in ecological adaptation/speciation. Analysis of effect direction and v-test statistics revealed that interspecific differentiation of most traits was driven by divergent natural selection, supporting the argument that ecological adaptation/speciation would proceed rapidly under coordinated selection on multiple traits. Our findings provide new insights into the understanding of genetic architecture of ecological adaptation and speciation in plants and help effective manipulation of specific genes or gene cluster in rice breeding.
Collapse
Affiliation(s)
- Qing-Lin Meng
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Cheng-Gen Qiang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ji-Long Li
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Mu-Fan Geng
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ning-Ning Ren
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Zhe Cai
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Mei-Xia Wang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zi-Hui Jiao
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fu-Min Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xian-Jun Song
- Key Laboratory of Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Song Ge
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
2
|
Aguirre-Bottger C, Zolla G. The best of both worlds: photosynthesis and Solanaceae biodiversity seeking a sustainable food and cosmetic industry. FRONTIERS IN PLANT SCIENCE 2024; 15:1362814. [PMID: 38434437 PMCID: PMC10904534 DOI: 10.3389/fpls.2024.1362814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024]
Affiliation(s)
| | - Gaston Zolla
- Grupo de Investigation en Fisiología Molecular de Plantas, Facultad de Agronomia, Universidad Nacional Agraria La Molina, Lima, Peru
| |
Collapse
|
3
|
Lupo Y, Moshelion M. The balance of survival: Comparative drought response in wild and domesticated tomatoes. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 339:111928. [PMID: 37992898 DOI: 10.1016/j.plantsci.2023.111928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/12/2023] [Accepted: 11/17/2023] [Indexed: 11/24/2023]
Abstract
Plants have the ability to undergo reversible behavioral, morphological, or physiological changes in response to environmental conditions. This plasticity enables plants to cope with uncertain environmental conditions, such as drought. A primary plastic trait is the rate of stomatal response to changes in ambient conditions, which determines the amount of water lost via transpiration, as well as levels of CO2 absorption, growth, and productivity. Here, we examined the differences between domesticated (S. lycopersicum cv. M82) and wild tomato (S. pennellii) species and their responses to drought stress. The plants were grown in pots in a functional phenotyping platform (FPP) in a semi-controlled environment greenhouse. We found that the domesticated tomato had a higher transpiration rate (E) and higher stomatal conductance (gs). The domesticated tomato also had greater biomass and greater leaf area under drought conditions, as compared to the wild tomato. Despite the domesticated tomato's higher E and higher gs, there was no difference between the photosynthetic rates (An) of the two lines. Moreover, the wild tomato had a higher maximum rate of rubisco activity (Vcmax), which might explain its greater leaf level and whole canopy water-use efficiency. The domesticated tomato's higher E and greater leaf area led to its earlier exposure to drought stress, as compared to the wild tomato, which maintained higher levels of soil water, enabling it to maintain steady rates of whole-canopy stomatal conductance (gsc) for extended periods. The wild tomato was also more sensitive to soil water availability and lowered its maximum transpiration rate (Emax) at a higher soil-water-content (SWC) level compared to the domesticated species. Our results suggest that the domestication of tomatoes favored morphological/anatomical performance traits over physiological efficiency.
Collapse
Affiliation(s)
- Yaniv Lupo
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel; French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boker, Israel
| | - Menachem Moshelion
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
| |
Collapse
|
4
|
Cutter AD. Speciation and development. Evol Dev 2023; 25:289-327. [PMID: 37545126 DOI: 10.1111/ede.12454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/13/2023] [Accepted: 07/20/2023] [Indexed: 08/08/2023]
Abstract
Understanding general principles about the origin of species remains one of the foundational challenges in evolutionary biology. The genomic divergence between groups of individuals can spawn hybrid inviability and hybrid sterility, which presents a tantalizing developmental problem. Divergent developmental programs may yield either conserved or divergent phenotypes relative to ancestral traits, both of which can be responsible for reproductive isolation during the speciation process. The genetic mechanisms of developmental evolution involve cis- and trans-acting gene regulatory change, protein-protein interactions, genetic network structures, dosage, and epigenetic regulation, all of which also have roots in population genetic and molecular evolutionary processes. Toward the goal of demystifying Darwin's "mystery of mysteries," this review integrates microevolutionary concepts of genetic change with principles of organismal development, establishing explicit links between population genetic process and developmental mechanisms in the production of macroevolutionary pattern. This integration aims to establish a more unified view of speciation that binds process and mechanism.
Collapse
Affiliation(s)
- Asher D Cutter
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
5
|
Nakayama H, Ichihashi Y, Kimura S. Diversity of tomato leaf form provides novel insights into breeding. BREEDING SCIENCE 2023; 73:76-85. [PMID: 37168814 PMCID: PMC10165341 DOI: 10.1270/jsbbs.22061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 08/29/2022] [Indexed: 05/13/2023]
Abstract
Tomato (Solanum lycopersicum L.) is cultivated widely globally. The crop exhibits tremendous morphological variations because of its long breeding history. Apart from the commercial tomato varieties, wild species and heirlooms are grown in certain regions of the world. Since the fruit constitutes the edible part, much of the agronomical research is focused on it. However, recent studies have indicated that leaf morphology influences fruit quality. As leaves are specialized photosynthetic organs and the vascular systems transport the photosynthetic products to sink organs, the architectural characteristics of the leaves have a strong influence on the final fruit quality. Therefore, comprehensive research focusing on both the fruit and leaf morphology is required for further tomato breeding. This review summarizes an overview of knowledge of the basic tomato leaf development, morphological diversification, and molecular mechanisms behind them and emphasizes its importance in breeding. Finally, we discuss how these findings and knowledge can be applied to future tomato breeding.
Collapse
Affiliation(s)
- Hokuto Nakayama
- Graduate School of Science, Department of Biological Sciences, The University of Tokyo, Science Build. #2, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan
- Department of Plant Biology, University of California Davis, One Shields Avenue, Davis, CA 95616, U.S.A.
- Corresponding author (e-mail: )
| | | | - Seisuke Kimura
- Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-Ku, Kyoto 603-8555, Japan
- Center for Plant Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-Ku, Kyoto 603-8555, Japan
| |
Collapse
|
6
|
Feng C, Zou S, Zhang J. Genetic architecture of microhabitat adaptation traits in a pair of sympatric Primulina species. BIOTECHNOL BIOTEC EQ 2023. [DOI: 10.1080/13102818.2023.2176169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Affiliation(s)
- Chen Feng
- Jiangxi Provincial Key Laboratory of ex situ Plant Conservation and Utilization, Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, PR China
| | - Shuaiyu Zou
- Jiangxi Provincial Key Laboratory of ex situ Plant Conservation and Utilization, Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, PR China
| | - Jie Zhang
- Jiangxi Provincial Key Laboratory of ex situ Plant Conservation and Utilization, Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, Jiangxi, PR China
| |
Collapse
|
7
|
Kosová V, Latzel V, Hadincová V, Münzbergová Z. Effect of DNA methylation, modified by 5-azaC, on ecophysiological responses of a clonal plant to changing climate. Sci Rep 2022; 12:17262. [PMID: 36241768 PMCID: PMC9568541 DOI: 10.1038/s41598-022-22125-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 10/10/2022] [Indexed: 01/06/2023] Open
Abstract
Epigenetic regulation of gene expression is expected to be an important mechanism behind phenotypic plasticity. Whether epigenetic regulation affects species ecophysiological adaptations to changing climate remains largely unexplored. We compared ecophysiological traits between individuals treated with 5-azaC, assumed to lead to DNA demethylation, with control individuals of a clonal grass originating from and grown under different climates, simulating different directions and magnitudes of climate change. We linked the ecophysiological data to proxies of fitness. Main effects of plant origin and cultivating conditions predicted variation in plant traits, but 5-azaC did not. Effects of 5-azaC interacted with conditions of cultivation and plant origin. The direction of the 5-azaC effects suggests that DNA methylation does not reflect species long-term adaptations to climate of origin and species likely epigenetically adjusted to the conditions experienced during experiment set-up. Ecophysiology translated to proxies of fitness, but the intensity and direction of the relationships were context dependent and affected by 5-azaC. The study suggests that effects of DNA methylation depend on conditions of plant origin and current climate. Direction of 5-azaC effects suggests limited role of epigenetic modifications in long-term adaptation of plants. It rather facilitates fast adaptations to temporal fluctuations of the environment.
Collapse
Affiliation(s)
- Veronika Kosová
- grid.4491.80000 0004 1937 116XDepartment of Botany, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vít Latzel
- grid.418095.10000 0001 1015 3316Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
| | - Věroslava Hadincová
- grid.418095.10000 0001 1015 3316Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
| | - Zuzana Münzbergová
- grid.4491.80000 0004 1937 116XDepartment of Botany, Faculty of Science, Charles University, Prague, Czech Republic ,grid.418095.10000 0001 1015 3316Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic
| |
Collapse
|
8
|
Earley AM, Temme AA, Cotter CR, Burke JM. Genomic regions associate with major axes of variation driven by gas exchange and leaf construction traits in cultivated sunflower (Helianthus annuus L.). THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1425-1438. [PMID: 35815412 PMCID: PMC9545426 DOI: 10.1111/tpj.15900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Stomata and leaf veins play an essential role in transpiration and the movement of water throughout leaves. These traits are thus thought to play a key role in the adaptation of plants to drought and a better understanding of the genetic basis of their variation and coordination could inform efforts to improve drought tolerance. Here, we explore patterns of variation and covariation in leaf anatomical traits and analyze their genetic architecture via genome-wide association (GWA) analyses in cultivated sunflower (Helianthus annuus L.). Traits related to stomatal density and morphology as well as lower-order veins were manually measured from digital images while the density of minor veins was estimated using a novel deep learning approach. Leaf, stomatal, and vein traits exhibited numerous significant correlations that generally followed expectations based on functional relationships. Correlated suites of traits could further be separated along three major principal component (PC) axes that were heavily influenced by variation in traits related to gas exchange, leaf hydraulics, and leaf construction. While there was limited evidence of colocalization when individual traits were subjected to GWA analyses, major multivariate PC axes that were most strongly influenced by several traits related to gas exchange or leaf construction did exhibit significant genomic associations. These results provide insight into the genetic basis of leaf trait covariation and showcase potential targets for future efforts aimed at modifying leaf anatomical traits in sunflower.
Collapse
Affiliation(s)
- Ashley M. Earley
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
| | - Andries A. Temme
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
- Division of Intensive Plant Food SystemsHumboldt‐Universität zu Berlin10117BerlinGermany
| | | | - John M. Burke
- Department of Plant BiologyUniversity of GeorgiaAthensGeorgiaUSA
| |
Collapse
|
9
|
Zheng Z, Hu H, Gao S, Zhou H, Luo W, Kage U, Liu C, Jia J. Leaf thickness of barley: genetic dissection, candidate genes prediction and its relationship with yield-related traits. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2022; 135:1843-1854. [PMID: 35348823 DOI: 10.1007/s00122-022-04076-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
In this first genetic study on assessing leaf thickness directly in cereals, major and environmentally stable QTL were detected in barley and candidate genes underlying a major locus were identified. Leaf thickness (LT) is an important characteristic affecting leaf functions which have been intensively studied. However, as LT has a small dimension in many plant species and technically difficult to measure, previous studies on this characteristic are often based on indirect estimations. In the first study of detecting QTL controlling LT by directly measuring the characteristic in barley, large and stable loci were detected from both field and glasshouse trials conducted in different cropping seasons by assessing a population of 201 recombinant inbred lines. Four loci (locating on chromosome arms 2H, 3H, 5H and 6H, respectively) were consistently detected for flag leaf thickness (FLT) in each of these trials. The one on 6H had the largest effect, with a maximum LOD 9.8 explaining up to 20.9% of phenotypic variance. FLT does not only show strong interactions with flag leaf width and flag leaf area but has also strong correlations with fertile tiller number, spike row types, kernel number per spike and heading date. Though with reduced efficiency, these loci were also detectable from assessing second last leaf of fully grown plants or even from assessing the third leaves of seedlings. Taking advantage of the high-quality genome assemblies for both parents of the mapping population used in this study, three candidate genes underlying the 6H QTL were predicted based on orthologous analysis. These results do not only broaden our understanding on genetic basis of LT and its relationship with other traits in cereal crops but also form the bases for cloning and functional analysis of genes regulating LT in barley.
Collapse
Affiliation(s)
- Zhi Zheng
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, QLD, 4067, Australia
| | - Haiyan Hu
- College of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, 453003, Henan, China
| | - Shang Gao
- School of Life Science, Tsinghua University, Beijing, 100084, China
| | - Hong Zhou
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, QLD, 4067, Australia
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China
| | - Wei Luo
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, QLD, 4067, Australia
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, Chengdu, 611130, China
| | - Udaykumar Kage
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, QLD, 4067, Australia
| | - Chunji Liu
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, QLD, 4067, Australia.
| | - Jizeng Jia
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| |
Collapse
|
10
|
Doll Y, Koga H, Tsukaya H. Callitriche as a potential model system for evolutionary studies on the dorsiventral distribution of stomata. PLANT SIGNALING & BEHAVIOR 2021; 16:1978201. [PMID: 34538209 PMCID: PMC8525970 DOI: 10.1080/15592324.2021.1978201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/03/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Controlling the distribution of stomata is crucial for the adaptation of plants to new, or changing environments. While many plant species produce stomata predominantly on the abaxial leaf surface (hypostomy), some produce stomata on both surfaces (amphistomy), and the remaining few produce them only on the adaxial surface (hyperstomy). Various selective pressures have driven the evolution of these three modes of stomatal distribution. Despite recent advances in our understanding of stomatal development and dorsiventral leaf polarity, the genetic basis for the evolution of different stomatal distributions is still unclear. Here, we propose the genus Callitriche as a new model system to investigate patterns in the evolution of stomatal distribution. Callitriche comprises species with diverse lifestyles, including terrestrial, amphibious, and obligately aquatic plants. We found that species in this genus cover all three modes of dorsiventral stomatal distribution, making it a desirable model for comparative and evolutionary analyses on distribution modes. We further characterized the genetic basis of the different distribution modes, focusing on the stomatal key transcription factor SPEECHLESS. Future research using the promising model system Callitriche would open a new direction for evolutionary developmental biology studies on stomata.
Collapse
Affiliation(s)
- Yuki Doll
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Koga
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Hirokazu Tsukaya
- Graduate School of Science, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
11
|
Nelson TC, Muir CD, Stathos AM, Vanderpool DD, Anderson K, Angert AL, Fishman L. Quantitative trait locus mapping reveals an independent genetic basis for joint divergence in leaf function, life-history, and floral traits between scarlet monkeyflower (Mimulus cardinalis) populations. AMERICAN JOURNAL OF BOTANY 2021; 108:844-856. [PMID: 34036561 DOI: 10.1002/ajb2.1660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 01/12/2021] [Indexed: 06/12/2023]
Abstract
PREMISE Across taxa, vegetative and floral traits that vary along a fast-slow life-history axis are often correlated with leaf functional traits arrayed along the leaf economics spectrum, suggesting a constrained set of adaptive trait combinations. Such broad-scale convergence may arise from genetic constraints imposed by pleiotropy (or tight linkage) within species, or from natural selection alone. Understanding the genetic basis of trait syndromes and their components is key to distinguishing these alternatives and predicting evolution in novel environments. METHODS We used a line-cross approach and quantitative trait locus (QTL) mapping to characterize the genetic basis of twenty leaf functional/physiological, life history, and floral traits in hybrids between annualized and perennial populations of scarlet monkeyflower (Mimulus cardinalis). RESULTS We mapped both single and multi-trait QTLs for life history, leaf function and reproductive traits, but found no evidence of genetic co-ordination across categories. A major QTL for three leaf functional traits (thickness, photosynthetic rate, and stomatal resistance) suggests that a simple shift in leaf anatomy may be key to adaptation to seasonally dry habitats. CONCLUSIONS Our results suggest that the co-ordination of resource-acquisitive leaf physiological traits with a fast life-history and more selfing mating system results from environmental selection rather than functional or genetic constraint. Independent assortment of distinct trait modules, as well as a simple genetic basis to leaf physiological traits associated with drought escape, may facilitate adaptation to changing climates.
Collapse
Affiliation(s)
- Thomas C Nelson
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Christopher D Muir
- Departments of Botany and Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- School of Life Sciences, University of Hawai'i, Honolulu, Hawai'i, 96822, USA
| | - Angela M Stathos
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Daniel D Vanderpool
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Kayli Anderson
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Amy L Angert
- Departments of Botany and Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Lila Fishman
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| |
Collapse
|
12
|
Evaluation of anatomical and physiological traits of Solanum pennellii Cor. associated with plant yield in tomato plants under water-limited conditions. Sci Rep 2020; 10:16052. [PMID: 32994541 PMCID: PMC7524713 DOI: 10.1038/s41598-020-73004-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 09/04/2020] [Indexed: 11/18/2022] Open
Abstract
Although intensively studied, few works had looked into S. pennellii’s ability to cope with water-deficit conditions from a breeding point of view. In this study, we assessed potential traits of S. pennellii, that had previously been linked to high yields in other plant species, under long-term water-limited conditions and made a parallel with plant yield. For this purpose, the drought-resistant tomato genotypes IL 3–5 and IL 10–1, and the drought-sensitive IL 2–5 and IL 7–1 at seed level, together with both parents the S. pennellii accession LA 716 and the cultivar M82 were kept at 50 and 100% ASW throughout the growing season. Our findings confirm the superiority of LA 716 under water-limited conditions compared to the other S. lycopersicum genotypes in terms of plant water status maintenance. Percentual reduction on plant yield was higher in IL 3–5 and IL 10–1 than in M82 plants, indicating no correlation between drought resistance on germination and plant productive stages. A strong positive correlation was found between fruit yield and A, gs, and Ψleaf at 50% ASW, suggesting these traits as important selection criteria. LT and gmin, LA 716’s most promising traits, did not show a linear correlation with fruit yield under low water regimes. This study unravels traits behind tomato performance under water-limited conditions and should work as guidance for breeders aiming at developing drought-resistant tomato cultivars.
Collapse
|
13
|
McKown KH, Bergmann DC. Stomatal development in the grasses: lessons from models and crops (and crop models). THE NEW PHYTOLOGIST 2020; 227:1636-1648. [PMID: 31985072 DOI: 10.1111/nph.16450] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/08/2020] [Indexed: 05/24/2023]
Abstract
When plants emerged from their aquatic origins to colonise land, they needed to avoid desiccation while still enabling gas and water exchange with the environment. The solution was the development of a waxy cuticle interrupted by epidermal pores, known as stomata. Despite the importance of stomata in plant physiology and their contribution to global water and carbon cycles, our knowledge of the genetic basis of stomatal development is limited mostly to the model dicot, Arabidopsis thaliana. This limitation is particularly troublesome when evaluating grasses, whose members represent our most agriculturally significant crops. Grass stomatal development follows a trajectory strikingly different from Arabidopsis and their uniquely shaped four-celled stomatal complexes are especially responsive to environmental inputs. Thus, understanding the development and regulation of these efficient complexes is of particular interest for the purposes of crop engineering. This review focuses on genetic regulation of grass stomatal development and prospects for the future, highlighting discoveries enabled by parallel comparative investigations in cereal crops and related genetic model species such as Brachypodium distachyon.
Collapse
Affiliation(s)
- Katelyn H McKown
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Dominique C Bergmann
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
- Howard Hughes Medical Institute, Stanford, CA, 94305, USA
| |
Collapse
|
14
|
Lana-Costa J, de Oliveira Silva FM, Batista-Silva W, Carolino DC, Senra RL, Medeiros DB, Martins SCV, Gago J, Araújo WL, Nunes-Nesi A. High Photosynthetic Rates in a Solanum pennellii Chromosome 2 QTL Is Explained by Biochemical and Photochemical Changes. FRONTIERS IN PLANT SCIENCE 2020; 11:794. [PMID: 32595679 PMCID: PMC7303335 DOI: 10.3389/fpls.2020.00794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/19/2020] [Indexed: 05/09/2023]
Abstract
Enhanced photosynthesis is strictly associated with to productivity and it can be accomplished by genetic approaches through identification of genetic variation. By using a Solanum pennellii introgression lines (ILs) population, it was previously verified that, under normal (CO2), IL 2-5 and 2-6 display increased photosynthetic rates by up to 20% in comparison with their parental background (M82). However, the physiological mechanisms involved in the enhanced CO2 assimilation exhibited by these lines remained unknown, precluding their use for further biotechnological applications. Thereby, here we attempted to uncover the physiological factors involved in the upregulation of photosynthesis in ILs 2-5 and 2-6 under normal (CO2) as well as under elevated (CO2). The results provide evidence for increased biochemical capacity (higher maximum carboxylation velocity and maximum electron transport rate) in plants from IL 2-5 and 2-6, whereas the diffusive components (stomatal and mesophyll conductances) were unaltered in these ILs in comparison to M82. Our analyses revealed that the higher photosynthetic rate observed in these ILs was associated with higher levels of starch as well as total protein levels, specially increased RuBisCO content. Further analyses performed in plants under high (CO2) confirmed that biochemical properties are involved in genetic variation on chromosome 2 related to enhanced photosynthesis.
Collapse
Affiliation(s)
- Jaciara Lana-Costa
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | | | - Diego Costa Carolino
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Renato Lima Senra
- Departamento de Bioquímica Aplicada, Universidade Federal de Viçosa, Viçosa, Brazil
| | - David B. Medeiros
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | - Jorge Gago
- Departament de Biologia, Institute of Agro-Environmental Research and Water Economy – INAGEA, Universitat de les Illes Balears, Palma, Spain
| | - Wagner L. Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Brazil
| |
Collapse
|
15
|
Sun S, Wang X, Wang K, Cui X. Dissection of complex traits of tomato in the post-genome era. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2020; 133:1763-1776. [PMID: 31745578 DOI: 10.1007/s00122-019-03478-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/09/2019] [Indexed: 06/10/2023]
Abstract
We present the main advances of dissection of complex traits in tomato by omics, the genes identified to control complex traits and the application of CRISPR/Cas9 in tomato breeding. Complex traits are believed to be under the control of multiple genes, each with different effects and interaction with environmental factors. Advance development of sequencing and molecular technologies has enabled the recognition of the genomic structure of most organisms and the identification of a nearly limitless number of markers that have made it to accelerate the speed of QTL identification and gene cloning. Meanwhile, multiomics have been used to identify the genetic variations among different tomato species, determine the expression profiles of genes in different tissues and at distinct developmental stages, and detect metabolites in different pathways and processes. The combination of these data facilitates to reveal mechanism underlying complex traits. Moreover, mutants generated by mutagens and genome editing provide relatively rich genetic variation for deciphering the complex traits and exploiting them in tomato breeding. In this article, we present the main advances of complex trait dissection in tomato by omics since the release of the tomato genome sequence in 2012. We provide further insight into some tomato complex traits because of the causal genetic variations discovered so far and explore the utilization of CRISPR/Cas9 for the modification of tomato complex traits.
Collapse
Affiliation(s)
- Shuai Sun
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xiaotian Wang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Ketao Wang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Xia Cui
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops of the Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- Sino-Dutch Joint Laboratory of Horticultural Genomics, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| |
Collapse
|
16
|
Agrawal AA. A scale‐dependent framework for trade‐offs, syndromes, and specialization in organismal biology. Ecology 2020; 101:e02924. [DOI: 10.1002/ecy.2924] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 02/02/2023]
Affiliation(s)
- Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853 USA
- Department of Entomology Cornell University Ithaca New York 14853 USA
| |
Collapse
|
17
|
Muir CD. Is Amphistomy an Adaptation to High Light? Optimality Models of Stomatal Traits along Light Gradients. Integr Comp Biol 2019. [PMID: 31141118 DOI: 10.1101/601377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
Stomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.
Collapse
|
18
|
Muir CD. Is Amphistomy an Adaptation to High Light? Optimality Models of Stomatal Traits along Light Gradients. Integr Comp Biol 2019; 59:571-584. [DOI: 10.1093/icb/icz085] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
AbstractStomata regulate the supply of CO2 for photosynthesis and the rate of water loss out of the leaf. The presence of stomata on both leaf surfaces, termed amphistomy, increases photosynthetic rate, is common in plants from high light habitats, and rare otherwise. In this study I use optimality models based on leaf energy budget and photosynthetic models to ask why amphistomy is common in high light habitats. I developed an R package leafoptimizer to solve for stomatal traits that optimally balance carbon gain with water loss in a given environment. The model predicts that amphistomy is common in high light because its marginal effect on carbon gain is greater than in the shade, but only if the costs of amphistomy are also lower under high light than in the shade. More generally, covariation between costs and benefits may explain why stomatal and other traits form discrete phenotypic clusters.
Collapse
|
19
|
Genetic architecture of quantitative flower and leaf traits in a pair of sympatric sister species of Primulina. Heredity (Edinb) 2018; 122:864-876. [PMID: 30518967 DOI: 10.1038/s41437-018-0170-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/19/2018] [Accepted: 11/19/2018] [Indexed: 01/10/2023] Open
Abstract
Flowers and leaves each represent suites of functionally interrelated traits that are often involved in species divergence and local adaptation. However, a major unresolved issue is how the individual component traits that make up a complex trait such as a flower evolve in a coordinated fashion to retain a high degree of functionality. We use a quantitative trait loci (QTL) approach to elucidate the genetic architecture of divergence in flower and leaf traits between the sister species Primulina depressa and Primulina danxiaensis, which grow sympatrically but in contrasting microhabitats. We found that flower traits were controlled by multiple QTL of small effect, while leaf physiological and morphological traits tended to be controlled by QTL of larger effect. The observed floral integration, manifested by a high degree overlap in both individual trait QTL and QTL for principal component scores (PCA QTL), may have been critical for evolutionary divergence of floral morphology in relation to their pollinators. This overlap suggests that direct selection on only one or a few of the component traits could have caused substantial divergence in other floral traits due to genetic correlations, while the low QTL overlap between floral and vegetative traits suggests that these trait suites are genetically unlinked and can evolve independently in response to different selective pressures corresponding to their distinct functions.
Collapse
|
20
|
A Megabase-Scale Deletion is Associated with Phenotypic Variation of Multiple Traits in Maize. Genetics 2018; 211:305-316. [PMID: 30389804 PMCID: PMC6325712 DOI: 10.1534/genetics.118.301567] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/26/2018] [Indexed: 11/18/2022] Open
Abstract
Genomic deletions are pervasive in the maize (Zea mays L.) genome, and play important roles in phenotypic variation and adaptive evolution. However, little is known about the biological functions of these genomic deletions. Here, we report the biological function of a megabase-scale deletion, which we identified by position-based cloning of the multi-trait weakened (muw) mutant, which is inherited as a single recessive locus. MUW was mapped to a 5.16-Mb region on chromosome 2. The 5.16-Mb deletion in the muw mutant led to the loss of 48 genes and was responsible for a set of phenotypic abnormities, including wilting leaves, poor yield performance, reduced plant height, increased stomatal density, and rapid water loss. While muw appears to have resulted from double-stranded break repair that was not dependent on intragenomic DNA homology, extensive duplication of maize genes may have mitigated its effects and facilitated its survival.
Collapse
|
21
|
de Oliveira Silva FM, Lichtenstein G, Alseekh S, Rosado-Souza L, Conte M, Suguiyama VF, Lira BS, Fanourakis D, Usadel B, Bhering LL, DaMatta FM, Sulpice R, Araújo WL, Rossi M, de Setta N, Fernie AR, Carrari F, Nunes-Nesi A. The genetic architecture of photosynthesis and plant growth-related traits in tomato. PLANT, CELL & ENVIRONMENT 2018; 41:327-341. [PMID: 29044606 DOI: 10.1111/pce.13084] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 09/22/2017] [Accepted: 09/23/2017] [Indexed: 05/22/2023]
Abstract
To identify genomic regions involved in the regulation of fundamental physiological processes such as photosynthesis and respiration, a population of Solanum pennellii introgression lines was analyzed. We determined phenotypes for physiological, metabolic, and growth related traits, including gas exchange and chlorophyll fluorescence parameters. Data analysis allowed the identification of 208 physiological and metabolic quantitative trait loci with 33 of these being associated to smaller intervals of the genomic regions, termed BINs. Eight BINs were identified that were associated with higher assimilation rates than the recurrent parent M82. Two and 10 genomic regions were related to shoot and root dry matter accumulation, respectively. Nine genomic regions were associated with starch levels, whereas 12 BINs were associated with the levels of other metabolites. Additionally, a comprehensive and detailed annotation of the genomic regions spanning these quantitative trait loci allowed us to identify 87 candidate genes that putatively control the investigated traits. We confirmed 8 of these at the level of variance in gene expression. Taken together, our results allowed the identification of candidate genes that most likely regulate photosynthesis, primary metabolism, and plant growth and as such provide new avenues for crop improvement.
Collapse
Affiliation(s)
| | - Gabriel Lichtenstein
- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaría, and Consejo Nacional de Investigaciones Científicas y Técnicas, B1712WAA, Castelar, Argentina
| | - Saleh Alseekh
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Laise Rosado-Souza
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Mariana Conte
- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaría, and Consejo Nacional de Investigaciones Científicas y Técnicas, B1712WAA, Castelar, Argentina
| | | | - Bruno Silvestre Lira
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-900, Brazil
| | - Dimitrios Fanourakis
- Department of Viticulture, Floriculture, Vegetable Crops and Plant Protection, GR, 71307, Heraklion, Greece
| | - Björn Usadel
- IBMG: Institute for Biology I, RWTH Aachen University, Worringer Weg 2, 52074, Aachen, Germany
- Forschungszentrum Jülich, IBG-2 Plant Sciences, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
| | - Leonardo Lopes Bhering
- Departamento de Biologia Geral, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Fábio M DaMatta
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Ronan Sulpice
- Plant Systems Biology Lab, Plant and AgriBiosciences Research Centre, Plant & Agribiosiences, National University of Ireland Galway, H91 TK33, Galway, Ireland
| | - Wagner L Araújo
- Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Magdalena Rossi
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-900, Brazil
| | - Nathalia de Setta
- Universidade Federal do ABC, 09606070, São Bernardo do Campo, São Paulo, Brazil
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Fernando Carrari
- Instituto de Biotecnología, Instituto Nacional de Tecnología Agropecuaría, and Consejo Nacional de Investigaciones Científicas y Técnicas, B1712WAA, Castelar, Argentina
| | - Adriano Nunes-Nesi
- Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil
| |
Collapse
|
22
|
Coneva V, Frank MH, Balaguer MADL, Li M, Sozzani R, Chitwood DH. Genetic Architecture and Molecular Networks Underlying Leaf Thickness in Desert-Adapted Tomato Solanum pennellii. PLANT PHYSIOLOGY 2017; 175:376-391. [PMID: 28794258 PMCID: PMC5580771 DOI: 10.1104/pp.17.00790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 08/01/2017] [Indexed: 05/05/2023]
Abstract
Thicker leaves allow plants to grow in water-limited conditions. However, our understanding of the genetic underpinnings of this highly functional leaf shape trait is poor. We used a custom-built confocal profilometer to directly measure leaf thickness in a set of introgression lines (ILs) derived from the desert tomato Solanum pennellii and identified quantitative trait loci. We report evidence of a complex genetic architecture of this trait and roles for both genetic and environmental factors. Several ILs with thick leaves have dramatically elongated palisade mesophyll cells and, in some cases, increased leaf ploidy. We characterized the thick IL2-5 and IL4-3 in detail and found increased mesophyll cell size and leaf ploidy levels, suggesting that endoreduplication underpins leaf thickness in tomato. Next, we queried the transcriptomes and inferred dynamic Bayesian networks of gene expression across early leaf ontogeny in these lines to compare the molecular networks that pattern leaf thickness. We show that thick ILs share S. pennellii-like expression profiles for putative regulators of cell shape and meristem determinacy as well as a general signature of cell cycle-related gene expression. However, our network data suggest that leaf thickness in these two lines is patterned at least partially by distinct mechanisms. Consistent with this hypothesis, double homozygote lines combining introgression segments from these two ILs show additive phenotypes, including thick leaves, higher ploidy levels, and larger palisade mesophyll cells. Collectively, these data establish a framework of genetic, anatomical, and molecular mechanisms that pattern leaf thickness in desert-adapted tomato.
Collapse
Affiliation(s)
| | | | - Maria A de Luis Balaguer
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | - Mao Li
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Rosangela Sozzani
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27695
| | | |
Collapse
|
23
|
Henning F, Machado-Schiaffino G, Baumgarten L, Meyer A. Genetic dissection of adaptive form and function in rapidly speciating cichlid fishes. Evolution 2017; 71:1297-1312. [PMID: 28211577 DOI: 10.1111/evo.13206] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 02/04/2017] [Indexed: 12/14/2022]
Abstract
Genes of major phenotypic effects and strong genetic correlations can facilitate adaptation, direct selective responses, and potentially lead to phenotypic convergence. However, the preponderance of this type of genetic architecture in repeatedly evolved adaptations remains unknown. Using hybrids between Haplochromis chilotes (thick-lipped) and Pundamilia nyererei (thin-lipped) we investigated the genetics underlying hypertrophied lips and elongated heads, traits that evolved repeatedly in cichlids. At least 25 loci of small-to-moderate and mainly additive effects were detected. Phenotypic variation in lip and head morphology was largely independent. Although several QTL overlapped for lip and head morphology traits, they were often of opposite effects. The distribution of effect signs suggests strong selection on lips. The fitness implications of several detected loci were demonstrated using a laboratory assay testing for the association between genotype and variation in foraging performance. The persistence of low fitness alleles in head morphology appears to be maintained through antagonistic pleiotropy/close linkage with positive-effect lip morphology alleles. Rather than being based on few major loci with strong positive genetic correlations, our results indicate that the evolution of the Lake Victoria thick-lipped ecomorph is the result of selection on numerous loci distributed throughout the genome.
Collapse
Affiliation(s)
- Frederico Henning
- Department of Biology, University of Konstanz, 78464, Konstanz, Germany.,Department of Genetics, CCS, Federal University of Rio de Janeiro, Ilha do Fundão, 21941-599, Rio de Janeiro, Brazil
| | | | - Lukas Baumgarten
- Department of Biology, University of Konstanz, 78464, Konstanz, Germany
| | - Axel Meyer
- Department of Biology, University of Konstanz, 78464, Konstanz, Germany
| |
Collapse
|
24
|
Zhang H, Mittal N, Leamy LJ, Barazani O, Song B. Back into the wild-Apply untapped genetic diversity of wild relatives for crop improvement. Evol Appl 2017; 10:5-24. [PMID: 28035232 PMCID: PMC5192947 DOI: 10.1111/eva.12434] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/07/2016] [Indexed: 12/18/2022] Open
Abstract
Deleterious effects of climate change and human activities, as well as diverse environmental stresses, present critical challenges to food production and the maintenance of natural diversity. These challenges may be met by the development of novel crop varieties with increased biotic or abiotic resistance that enables them to thrive in marginal lands. However, considering the diverse interactions between crops and environmental factors, it is surprising that evolutionary principles have been underexploited in addressing these food and environmental challenges. Compared with domesticated cultivars, crop wild relatives (CWRs) have been challenged in natural environments for thousands of years and maintain a much higher level of genetic diversity. In this review, we highlight the significance of CWRs for crop improvement by providing examples of CWRs that have been used to increase biotic and abiotic stress resistance/tolerance and overall yield in various crop species. We also discuss the surge of advanced biotechnologies, such as next-generation sequencing technologies and omics, with particular emphasis on how they have facilitated gene discovery in CWRs. We end the review by discussing the available resources and conservation of CWRs, including the urgent need for CWR prioritization and collection to ensure continuous crop improvement for food sustainability.
Collapse
Affiliation(s)
- Hengyou Zhang
- Department of Biological SciencesUniversity of North Carolina at CharlotteCharlotteNCUSA
| | - Neha Mittal
- Department of Biological SciencesUniversity of North Carolina at CharlotteCharlotteNCUSA
| | - Larry J. Leamy
- Department of Biological SciencesUniversity of North Carolina at CharlotteCharlotteNCUSA
| | - Oz Barazani
- The Institute for Plant SciencesIsrael Plant Gene BankAgricultural Research OrganizationBet DaganIsrael
| | - Bao‐Hua Song
- Department of Biological SciencesUniversity of North Carolina at CharlotteCharlotteNCUSA
| |
Collapse
|
25
|
Fulop D, Ranjan A, Ofner I, Covington MF, Chitwood DH, West D, Ichihashi Y, Headland L, Zamir D, Maloof JN, Sinha NR. A New Advanced Backcross Tomato Population Enables High Resolution Leaf QTL Mapping and Gene Identification. G3 (BETHESDA, MD.) 2016; 6:3169-3184. [PMID: 27510891 PMCID: PMC5068939 DOI: 10.1534/g3.116.030536] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 08/01/2016] [Indexed: 12/23/2022]
Abstract
Quantitative Trait Loci (QTL) mapping is a powerful technique for dissecting the genetic basis of traits and species differences. Established tomato mapping populations between domesticated tomato (Solanum lycopersicum) and its more distant interfertile relatives typically follow a near isogenic line (NIL) design, such as the S. pennellii Introgression Line (IL) population, with a single wild introgression per line in an otherwise domesticated genetic background. Here, we report on a new advanced backcross QTL mapping resource for tomato, derived from a cross between the M82 tomato cultivar and S. pennellii This so-called Backcrossed Inbred Line (BIL) population is comprised of a mix of BC2 and BC3 lines, with domesticated tomato as the recurrent parent. The BIL population is complementary to the existing S. pennellii IL population, with which it shares parents. Using the BILs, we mapped traits for leaf complexity, leaflet shape, and flowering time. We demonstrate the utility of the BILs for fine-mapping QTL, particularly QTL initially mapped in the ILs, by fine-mapping several QTL to single or few candidate genes. Moreover, we confirm the value of a backcrossed population with multiple introgressions per line, such as the BILs, for epistatic QTL mapping. Our work was further enabled by the development of our own statistical inference and visualization tools, namely a heterogeneous hidden Markov model for genotyping the lines, and by using state-of-the-art sparse regression techniques for QTL mapping.
Collapse
Affiliation(s)
- Daniel Fulop
- Department of Plant Biology, University of California at Davis, California 95616
| | - Aashish Ranjan
- Department of Plant Biology, University of California at Davis, California 95616
| | - Itai Ofner
- Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Michael F Covington
- Department of Plant Biology, University of California at Davis, California 95616
| | - Daniel H Chitwood
- Department of Plant Biology, University of California at Davis, California 95616
| | - Donelly West
- Department of Plant Biology, University of California at Davis, California 95616
| | - Yasunori Ichihashi
- Department of Plant Biology, University of California at Davis, California 95616
| | - Lauren Headland
- Department of Plant Biology, University of California at Davis, California 95616
| | - Daniel Zamir
- Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Julin N Maloof
- Department of Plant Biology, University of California at Davis, California 95616
| | - Neelima R Sinha
- Department of Plant Biology, University of California at Davis, California 95616
| |
Collapse
|
26
|
Ranjan A, Budke JM, Rowland SD, Chitwood DH, Kumar R, Carriedo L, Ichihashi Y, Zumstein K, Maloof JN, Sinha NR. eQTL Regulating Transcript Levels Associated with Diverse Biological Processes in Tomato. PLANT PHYSIOLOGY 2016; 172:328-40. [PMID: 27418589 PMCID: PMC5074602 DOI: 10.1104/pp.16.00289] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 07/11/2016] [Indexed: 05/18/2023]
Abstract
Variation in gene expression, in addition to sequence polymorphisms, is known to influence developmental, physiological, and metabolic traits in plants. Genetic mapping populations have facilitated identification of expression quantitative trait loci (eQTL), the genetic determinants of variation in gene expression patterns. We used an introgression population developed from the wild desert-adapted Solanum pennellii and domesticated tomato (Solanum lycopersicum) to identify the genetic basis of transcript level variation. We established the effect of each introgression on the transcriptome and identified approximately 7,200 eQTL regulating the steady-state transcript levels of 5,300 genes. Barnes-Hut t-distributed stochastic neighbor embedding clustering identified 42 modules revealing novel associations between transcript level patterns and biological processes. The results showed a complex genetic architecture of global transcript abundance pattern in tomato. Several genetic hot spots regulating a large number of transcript level patterns relating to diverse biological processes such as plant defense and photosynthesis were identified. Important eQTL regulating transcript level patterns were related to leaf number and complexity as well as hypocotyl length. Genes associated with leaf development showed an inverse correlation with photosynthetic gene expression, but eQTL regulating genes associated with leaf development and photosynthesis were dispersed across the genome. This comprehensive eQTL analysis details the influence of these loci on plant phenotypes and will be a valuable community resource for investigations on the genetic effects of eQTL on phenotypic traits in tomato.
Collapse
Affiliation(s)
- Aashish Ranjan
- Department of Plant Biology, University of California, Davis, California 95616
| | - Jessica M Budke
- Department of Plant Biology, University of California, Davis, California 95616
| | - Steven D Rowland
- Department of Plant Biology, University of California, Davis, California 95616
| | - Daniel H Chitwood
- Department of Plant Biology, University of California, Davis, California 95616
| | - Ravi Kumar
- Department of Plant Biology, University of California, Davis, California 95616
| | - Leonela Carriedo
- Department of Plant Biology, University of California, Davis, California 95616
| | - Yasunori Ichihashi
- Department of Plant Biology, University of California, Davis, California 95616
| | - Kristina Zumstein
- Department of Plant Biology, University of California, Davis, California 95616
| | - Julin N Maloof
- Department of Plant Biology, University of California, Davis, California 95616
| | - Neelima R Sinha
- Department of Plant Biology, University of California, Davis, California 95616
| |
Collapse
|
27
|
Ferris KG, Barnett LL, Blackman BK, Willis JH. The genetic architecture of local adaptation and reproductive isolation in sympatry within the Mimulus guttatus species complex. Mol Ecol 2016; 26:208-224. [PMID: 27439150 DOI: 10.1111/mec.13763] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 06/30/2016] [Accepted: 07/05/2016] [Indexed: 01/05/2023]
Abstract
The genetic architecture of local adaptation has been of central interest to evolutionary biologists since the modern synthesis. In addition to classic theory on the effect size of adaptive mutations by Fisher, Kimura and Orr, recent theory addresses the genetic architecture of local adaptation in the face of ongoing gene flow. This theory predicts that with substantial gene flow between populations local adaptation should proceed primarily through mutations of large effect or tightly linked clusters of smaller effect loci. In this study, we investigate the genetic architecture of divergence in flowering time, mating system-related traits, and leaf shape between Mimulus laciniatus and a sympatric population of its close relative M. guttatus. These three traits are probably involved in M. laciniatus' adaptation to a dry, exposed granite outcrop environment. Flowering time and mating system differences are also reproductive isolating barriers making them 'magic traits'. Phenotypic hybrids in this population provide evidence of recent gene flow. Using next-generation sequencing, we generate dense SNP markers across the genome and map quantitative trait loci (QTLs) involved in flowering time, flower size and leaf shape. We find that interspecific divergence in all three traits is due to few QTL of large effect including a highly pleiotropic QTL on chromosome 8. This QTL region contains the pleiotropic candidate gene TCP4 and is involved in ecologically important phenotypes in other Mimulus species. Our results are consistent with theory, indicating that local adaptation and reproductive isolation with gene flow should be due to few loci with large and pleiotropic effects.
Collapse
Affiliation(s)
- Kathleen G Ferris
- Department of Biology, Duke University, 125 Science Drive, Durham, NC, 27705, USA
| | - Laryssa L Barnett
- Department of Biology, Duke University, 125 Science Drive, Durham, NC, 27705, USA
| | - Benjamin K Blackman
- Department of Biology, University of Virginia, 485 McCormick Road, Charlottesville, VA, 22904, USA
| | - John H Willis
- Department of Biology, Duke University, 125 Science Drive, Durham, NC, 27705, USA
| |
Collapse
|
28
|
Holmes MW, Hammond TT, Wogan GOU, Walsh RE, LaBarbera K, Wommack EA, Martins FM, Crawford JC, Mack KL, Bloch LM, Nachman MW. Natural history collections as windows on evolutionary processes. Mol Ecol 2016; 25:864-81. [PMID: 26757135 DOI: 10.1111/mec.13529] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/30/2015] [Accepted: 12/27/2015] [Indexed: 12/14/2022]
Abstract
Natural history collections provide an immense record of biodiversity on Earth. These repositories have traditionally been used to address fundamental questions in biogeography, systematics and conservation. However, they also hold the potential for studying evolution directly. While some of the best direct observations of evolution have come from long-term field studies or from experimental studies in the laboratory, natural history collections are providing new insights into evolutionary change in natural populations. By comparing phenotypic and genotypic changes in populations through time, natural history collections provide a window into evolutionary processes. Recent studies utilizing this approach have revealed some dramatic instances of phenotypic change over short timescales in response to presumably strong selective pressures. In some instances, evolutionary change can be paired with environmental change, providing a context for potential selective forces. Moreover, in a few cases, the genetic basis of phenotypic change is well understood, allowing for insight into adaptive change at multiple levels. These kinds of studies open the door to a wide range of previously intractable questions by enabling the study of evolution through time, analogous to experimental studies in the laboratory, but amenable to a diversity of species over longer timescales in natural populations.
Collapse
Affiliation(s)
- Michael W Holmes
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA.,Department of Biology, Coastal Carolina University, Conway, SC, 29528, USA
| | - Talisin T Hammond
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Guinevere O U Wogan
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Rachel E Walsh
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Katie LaBarbera
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Elizabeth A Wommack
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA.,Department of Zoology and Physiology, University of Wyoming Museum of Vertebrates, Laramie, WY, 82071, USA
| | - Felipe M Martins
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Jeremy C Crawford
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Katya L Mack
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Luke M Bloch
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| | - Michael W Nachman
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, 97420-3140, USA
| |
Collapse
|
29
|
Nunes-Nesi A, Nascimento VDL, de Oliveira Silva FM, Zsögön A, Araújo WL, Sulpice R. Natural genetic variation for morphological and molecular determinants of plant growth and yield. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:2989-3001. [PMID: 27012286 DOI: 10.1093/jxb/erw124] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The rates of increase in yield of the main commercial crops have been steadily falling in many areas worldwide. This generates concerns because there is a growing demand for plant biomass due to the increasing population. Plant yield should thus be improved in the context of climate change and decreasing natural resources. It is a major challenge which could be tackled by improving and/or altering light-use efficiency, CO2 uptake and fixation, primary metabolism, plant architecture and leaf morphology, and developmental plant processes. In this review, we discuss some of the traits which could lead to yield increase, with a focus on how natural genetic variation could be harnessed. Moreover, we provide insights for advancing our understanding of the molecular aspects governing plant growth and yield, and propose future avenues for improvement of crop yield. We also suggest that knowledge accumulated over the last decade in the field of molecular physiology should be integrated into new ideotypes.
Collapse
Affiliation(s)
- Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Vitor de Laia Nascimento
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Franklin Magnum de Oliveira Silva
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Agustin Zsögön
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | - Ronan Sulpice
- National University of Ireland, Galway, Plant Systems Biology Lab, Plant and AgriBiosciences Research Centre, School of Natural Sciences, Galway, Ireland
| |
Collapse
|
30
|
Tapia G, Méndez J, Inostroza L. Different combinations of morpho-physiological traits are responsible for tolerance to drought in wild tomatoes Solanum chilense and Solanum peruvianum. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:406-16. [PMID: 26499789 DOI: 10.1111/plb.12409] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/21/2015] [Indexed: 05/23/2023]
Abstract
Herbaceous species can modify leaf structure during the growing season in response to drought stress and water loss. Evolution can select combinations of traits in plants for efficient water use in restricted environments. We investigated plant traits that mediate adaptation and acclimation to water stress in two herbaceous drought-tolerant species. Anatomical, morphological and physiological traits related to stems and leaves were examined under optimal watering (OW) and a long period of restricted watering (RW) in 11 accessions from three Solanaceae species (Solanum chilense, S. peruvianum and S. lycopersicum). The relationships between these traits were tested using linear regression and PCA. There were significant differences in anatomical traits between the species under both OW and RW, where leaf area correlated with stem diameter. Proline and total carbohydrates accumulated highly in S. chilense and S. peruvianum, respectively, and these osmolytes were strongly correlated with increased osmotic potential. Stomatal density varied between species but not between acclimation treatments, while stomatal rate was significantly higher in wild tomatoes. There was a strong positive relationship between stem growth rate and a group of traits together expressed as total stomatal number. Total stomata is described by integration of leaf area, stomatal density, height and internode length. It is proposed that constitutive adaptations and modifications through acclimation that mediate RW play an important role in tolerance to drought stress in herbaceous plants. The capacity for growth under drought stress was not associated with any single combination of traits in wild tomatoes, since the two species differed in relative levels of expression of various phenotypic traits.
Collapse
Affiliation(s)
- G Tapia
- Unidad de Recursos Genéticos Vegetales, Instituto de Investigaciones Agropecuarias, INIA-Quilamapu, Chillán, Chile
| | - J Méndez
- Unidad de Recursos Genéticos Vegetales, Instituto de Investigaciones Agropecuarias, INIA-Quilamapu, Chillán, Chile
| | - L Inostroza
- Unidad de Recursos Genéticos Vegetales, Instituto de Investigaciones Agropecuarias, INIA-Quilamapu, Chillán, Chile
| |
Collapse
|
31
|
Guerrero RF, Posto AL, Moyle LC, Hahn MW. Genome-wide patterns of regulatory divergence revealed by introgression lines. Evolution 2016; 70:696-706. [PMID: 26842879 DOI: 10.1111/evo.12875] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 01/24/2016] [Indexed: 01/03/2023]
Abstract
Understanding the genetic basis for changes in transcriptional regulation is an important aspect of understanding phenotypic evolution. Using interspecific introgression lines, we infer the mechanisms of divergence in genome-wide patterns of gene expression between the nightshades Solanum pennellii and S. lycopersicum (domesticated tomato). We find that cis- and trans-regulatory changes have had qualitatively similar contributions to divergence in this clade, unlike results from other systems. Additionally, expression data from four tissues (shoot apex, ripe fruit, pollen, and seed) suggest that introgressed regions in these hybrid lines tend to be downregulated, while background (nonintrogressed) genes tend to be upregulated. Finally, we find no evidence for an association between the magnitude of differential expression in NILs and previously determined sterility phenotypes. Our results contradict previous predictions of the predominant role of cis- over trans-regulatory divergence between species, and do not support a major role for gross genome-wide misregulation in reproductive isolation between these species.
Collapse
Affiliation(s)
- Rafael F Guerrero
- Department of Biology, Indiana University, Bloomington, Indiana, 47405.
| | - Amanda L Posto
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Leonie C Moyle
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Matthew W Hahn
- Department of Biology, Indiana University, Bloomington, Indiana, 47405.,School of Informatics and Computing, Indiana University, Bloomington, Indiana, 47405
| |
Collapse
|
32
|
Muir CD. Making pore choices: repeated regime shifts in stomatal ratio. Proc Biol Sci 2015; 282:20151498. [PMID: 26269502 PMCID: PMC4632635 DOI: 10.1098/rspb.2015.1498] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 07/22/2015] [Indexed: 11/12/2022] Open
Abstract
Ecologically important traits do not evolve without limits. Instead, evolution is constrained by the set of available and viable phenotypes. In particular, natural selection may only favour a narrow range of adaptive optima constrained within selective regimes. Here, I integrate data with theory to test whether selection explains phenotypic constraint. A global database of 599 plant species from 94 families shows that stomatal ratio, a trait affecting photosynthesis and defence against pathogens, is highly constrained. Most plants have their stomata on the lower leaf surface (hypostomy), but species with half their stomata on each surface (amphistomy) form a distinct mode in the trait distribution. A model based on a trade-off between maximizing photosynthesis and a fitness cost of upper stomata predicts a limited number of adaptive solutions, leading to a multimodal trait distribution. Phylogenetic comparisons show that amphistomy is the most common among fast-growing species, supporting the view that CO2 diffusion is under strong selection. These results indicate that selective optima stay within a relatively stable set of selective regimes over macroevolutionary time.
Collapse
Affiliation(s)
- Christopher D Muir
- Biodiversity Research Centre and Botany Department, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
| |
Collapse
|