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Zhao S, Rong J. Single-cell RNA-seq reveals a link of ovule abortion and sugar transport in Camellia oleifera. FRONTIERS IN PLANT SCIENCE 2024; 15:1274013. [PMID: 38371413 PMCID: PMC10869455 DOI: 10.3389/fpls.2024.1274013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024]
Abstract
Camellia oleifera is the most important woody oil crop in China. Seed number per fruit is an important yield trait in C. oleifera. Ovule abortion is generally observed in C. oleifera and significantly decreases the seed number per fruit. However, the mechanisms of ovule abortion remain poorly understood at present. Single-cell RNA sequencing (scRNA-seq) was performed using mature ovaries of two C. oleifera varieties with different ovule abortion rates (OARs). In total, 20,526 high-quality cells were obtained, and 18 putative cell clusters were identified. Six cell types including female gametophyte, protoxylem, protophloem, procambium, epidermis, and parenchyma cells were identified from three main tissue types of ovule, placenta, and pericarp inner layer. A comparative analysis on scRNA-seq data between high- and low-OAR varieties demonstrated that the overall expression of CoSWEET and CoCWINV in procambium cells, and CoSTP in the integument was significantly upregulated in the low-OAR variety. Both the infertile ovule before pollination and the abortion ovule producing after compatible pollination might be attributed to selective abortion caused by low sugar levels in the apoplast around procambium cells and a low capability of hexose uptake in the integument. Here, the first single-cell transcriptional landscape is reported in woody crop ovaries. Our investigation demonstrates that ovule abortion may be related to sugar transport in placenta and ovules and sheds light on further deciphering the mechanism of regulating sugar transport and the improvement of seed yield in C. oleifera.
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Affiliation(s)
- Songzi Zhao
- Jiangxi Province Key Laboratory of Camellia Germplasm Conservation and Utilization, Jiangxi Academy of Forestry, Nanchang, China
| | - Jun Rong
- Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity, Center for Watershed Ecology, Institute of Life Science and School of Life Sciences, Nanchang University, Nanchang, China
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Cardel YJ, Koptur S. Locations of seed abortion in response to defoliation differ with pollen source in a native perennial legume herb. AMERICAN JOURNAL OF BOTANY 2022; 109:1730-1740. [PMID: 36088615 DOI: 10.1002/ajb2.16055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
PREMISE In many flowering plants, flowers contain more ovules than fruits have seeds. What determines which ovules become seeds? When photosynthates are limited, as may happen when plants lose leaf area to herbivory, fewer fertilized ovules become seeds. METHODS Greenhouse-grown ramets of distinct individuals of a perennial herbaceous legume were manually defoliated to various levels determined in the field, then self- or cross-pollinated. For each seed produced, we recorded its position in the fruit and its mass. From a subset of seeds from different treatments and positions in the fruits, we grew seedlings and measured their dry mass. RESULTS Ovules were aborted more frequently in fruits from flowers that were self-pollinated and from those on plants with higher levels of defoliation. Ovules in the basal portion of the fruits were more likely to be aborted than those at the stigmatic end; this pattern was most pronounced for fruits after self-pollination with high levels of defoliation. Total number of seeds produced and seed mass per pod were greatest in cross-pollinated fruits after no or low levels of defoliation. Mean individual seed mass was greater for fruits with fewer seeds, indicating a trade-off between seed number and seed mass. Seedling dry mass (a measure of vigor) was greatest for seeds in the middle positions of fruit produced by cross-pollination after severe herbivory; no positional differences were seen for seeds from self-pollinated fruits. CONCLUSIONS Observed locations of seed abortion may have been selected not only by defoliation, but in part by propensity for dispersal, while positional differences in seedling vigor may be related to seed size and differential maternal allocation based on pollination treatment and leaf area lost.
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Affiliation(s)
- Yuria J Cardel
- Department of Biological Sciences, Institute of the Environment, International Center for Tropical Botany, Florida International University, University Park, Miami, FL, 33199, USA
| | - Suzanne Koptur
- Department of Biological Sciences, Institute of the Environment, International Center for Tropical Botany, Florida International University, University Park, Miami, FL, 33199, USA
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Do Reproductive Traits of Invasive Populations of Scotch Broom, Cytisus scoparius (Fabaceae), Outperform Native Populations? PLANTS 2022; 11:plants11162158. [PMID: 36015460 PMCID: PMC9414750 DOI: 10.3390/plants11162158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/08/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022]
Abstract
Reproductive traits are among the most important factors in determining the success of species establishment and invasion in a new area. Studies on transcontinental invasions have revealed that invasive species perform better in the invasive range than in their native ranges. We assumed that the same regularity exists in intracontinental invasions and thus investigated whether the reproductive traits of Scotch broom, Cytisus scoparius, perform better in the alien invasive range in Europe compared to its native range in the same continent. The aim of this research was to reveal the potential and realised fecundity of C. scoparius in its native and invasive ranges, as well as relationships with the size of pods, habitat type, and how these traits vary at the same site in different years. The results of this study were not able to unambiguously confirm our hypothesis that C. scoparius in the invasive range in Lithuania, specifically in the southern part of the Boreal biogeographical region, outperform plants in the native range with regard to the analysed reproductive traits. Potential fecundity of C. scoparius in the native range was significantly higher than in the invaded range; however, realised fecundity was not significantly different between the native and invasive ranges. The pod length was similar in both ranges, whereas the pod width was significantly greater in the invasive range than in the native range. The results suggest that the number of ovules per pod, number of matured seeds, and the size of pods are related with the type of habitat and local environmental conditions in the habitat. Although many studies on other species have confirmed higher fecundity and overall better performance of plants in the invasive range than in the native range on other continents, this rule probably cannot be applied for intracontinental invasive species occurring in relatively close geographical regions to their native ranges.
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Shen S, Liang XG, Zhang L, Zhao X, Liu YP, Lin S, Gao Z, Wang P, Wang ZM, Zhou SL. Intervening in sibling competition for assimilates by controlled pollination prevents seed abortion under postpollination drought in maize. PLANT, CELL & ENVIRONMENT 2020; 43:903-919. [PMID: 31851373 DOI: 10.1111/pce.13704] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 12/07/2019] [Indexed: 06/10/2023]
Abstract
During maize production, drought throughout the flowering stage usually induces seed abortion and yield losses. The influence of postpollination drought stress on seed abortion and its underlying mechanisms are not well characterized. By intervening in the competition for assimilates between kernel siblings under different degrees of postpollination drought stresses accompanied by synchronous pollination (SP) and incomplete pollination (ICP) approaches, the mechanisms of postpollination abortion were investigated at physiological and molecular levels. Upon SP treatment, up to 15% of the fertilized apical kernels were aborted in the drought-exacerbated competition for assimilates. The aborted kernels exhibited weak sucrose hydrolysis and starch synthesis but promoted the synthesis of trehalose-6-phosphate and ethylene. In ICP where basal pollination was prevented, apical kernel growth was restored with reinstated sucrose metabolism and starch synthesis and promoted sucrose and hexose levels under drought stress. In addition, the equilibrium between ethylene and polyamine in response to the drought and pollination treatments was associated with the abortion process. We conclude that competition for assimilates drives postpollination kernel abortion, whereas differences in sugar metabolism and the equilibrium between ethylene and polyamines may be relevant to the "live or die" choice of kernel siblings during this competition.
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Affiliation(s)
- Si Shen
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
| | - Xiao-Gui Liang
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
| | - Li Zhang
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
- College of Agronomy, Henan Agricultural University, Zhengzhou, China
| | - Xue Zhao
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
| | - Yun-Peng Liu
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
- School of Biological and Environmental Engineering, Binzhou University, Binzhou, China
| | - Shan Lin
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
| | - Zhen Gao
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
| | - Pu Wang
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
- Scientific Observing and Experimental Station of Wuqiao for Crop Water Use Efficiency, Ministry of Agriculture and Rural Affairs, Wuqiao, China
- Innovation Center of Agricultural Technology for Lowland Plain of Hebei, Wuqiao, China
| | - Zhi-Min Wang
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
- Scientific Observing and Experimental Station of Wuqiao for Crop Water Use Efficiency, Ministry of Agriculture and Rural Affairs, Wuqiao, China
- Innovation Center of Agricultural Technology for Lowland Plain of Hebei, Wuqiao, China
| | - Shun-Li Zhou
- College of Agronomy & Biotechnology, China Agricultural University, Beijing, China
- Scientific Observing and Experimental Station of Wuqiao for Crop Water Use Efficiency, Ministry of Agriculture and Rural Affairs, Wuqiao, China
- Innovation Center of Agricultural Technology for Lowland Plain of Hebei, Wuqiao, China
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Shen S, Zhang L, Liang XG, Zhao X, Lin S, Qu LH, Liu YP, Gao Z, Ruan YL, Zhou SL. Delayed pollination and low availability of assimilates are major factors causing maize kernel abortion. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1599-1613. [PMID: 29365129 PMCID: PMC5888920 DOI: 10.1093/jxb/ery013] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 01/09/2018] [Indexed: 05/05/2023]
Abstract
Selective seed abortion is a survival strategy adopted by many species that sacrifices some seeds to allow the remaining ones to set. While in evolutionary terms this is a successful approach, it causes huge losses to crop yields. A pollination time gap (PTG) has been suggested to be associated with position-related grain abortion. To test this hypothesis, we developed a novel approach to alter the natural pattern of maize (Zea mays L.) pollination and to examine the impact of PTGs on kernel growth and the underlying physiological basis. When apical and basal kernels were synchronously pollinated, the basal kernels set and matured but the apical kernels were aborted at an early stage. Delaying pollination to the basal ovaries suppressed their development and reduced invertase activity and sugar levels, which allowed the apical kernels to set and grow normally. In situ localization revealed normal cell wall invertase activity in apical and basal kernels under synchronous pollination but reduced activity in the delayed-pollinated kernels independent of their position. Starch, which was abundant in basal kernel areas, was absent in the apical kernel regions under synchronous pollination but apparent with delayed pollination. Our analyses identified PTG-related sink strength and a low level of local assimilates as the main causes of grain abortion.
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Affiliation(s)
- Si Shen
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Li Zhang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Xiao-Gui Liang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Xue Zhao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Shan Lin
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Ling-Hua Qu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yun-Peng Liu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Zhen Gao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yong-Ling Ruan
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
| | - Shun-Li Zhou
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
- Scientific Observation and Experimental Station of Crop High Efficient Use of Water in Wuqiao, Ministry of Agriculture, Wuqiao, China
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Niklas KJ, Cobb ED, Kutschera U. Did meiosis evolve before sex and the evolution of eukaryotic life cycles? Bioessays 2014; 36:1091-101. [PMID: 25143284 DOI: 10.1002/bies.201400045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Biologists have long theorized about the evolution of life cycles, meiosis, and sexual reproduction. We revisit these topics and propose that the fundamental difference between life cycles is where and when multicellularity is expressed. We develop a scenario to explain the evolutionary transition from the life cycle of a unicellular organism to one in which multicellularity is expressed in either the haploid or diploid phase, or both. We propose further that meiosis might have evolved as a mechanism to correct for spontaneous whole-genome duplication (auto-polyploidy) and thus before the evolution of sexual reproduction sensu stricto (i.e. the formation of a diploid zygote via the fusion of haploid gametes) in the major eukaryotic clades. In addition, we propose, as others have, that sexual reproduction, which predominates in all eukaryotic clades, has many different advantages among which is that it produces variability among offspring and thus reduces sibling competition.
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Affiliation(s)
- Karl J Niklas
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
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Ma K, Song Y, Huang Z, Lin L, Zhang Z, Zhang D. The low fertility of Chinese white poplar: dynamic changes in anatomical structure, endogenous hormone concentrations, and key gene expression in the reproduction of a naturally occurring hybrid. PLANT CELL REPORTS 2013; 32:401-414. [PMID: 23224581 DOI: 10.1007/s00299-012-1373-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/20/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
KEY MESSAGE : We report that low fertility during intraspecific hybridization in Chinese white poplar was caused by prefertilization barriers, reduced ovules, and embryonic abortion. Hormone concentrations and gene expression patterns were also evaluated during the fertilization process. Hybrid vigor holds tremendous potential for yield increases and trait improvement; however, some hybridization combinations within Populus show very low fertility. To explore the causes of this low fertility in intraspecific hybridization of Chinese white poplar, we examined anatomical structure, hormone levels and expression of key genes in two unique crossing combinations of Populus × tomentosa "Pt02" × P. × tomentosa "LM50", and (P. × tomentosa × P. alba cv. bolleana "Ptb") × P. × tomentosa "LM50". The seed set potential in the intraspecific hybridization P. × tomentosa "Pt02" × P. × tomentosa "LM50" was quite low, which was likely caused by prefertilization barriers, reduced ovule numbers, and embryonic abortion in ovaries. During intraspecific hybridization, we found reduced indoleacetic acid (IAA) in pistils, which may cause pollen tube deformations and increased IAA in heart-stage embryos, which may affect embryo development. Gibberellin A3 (GA3) decreased from the zygote dormancy stage to globular-stage embryos, which may be caused by failure of fertilization in specific embryos. The maximum zeatin (Z) concentration was found in heart-stage embryos, but Z concentrations quickly decreased, which may affect endosperm development. Increasing concentrations of abscisic acid (ABA) during zygote dormancy and eight-cell proembryo stages likely induced abscission of the infructescence. High ABA concentrations also regulated embryo maturity. Measurement of genes expression showed that high expression of SRK and/or SLG may result in rejection of pollen by stigmatic papillae through a mechanism, reminiscent of self-incompatibility. Also, low expression of LEC1 and FUS3 may cause embryonic abortion. Identification and eventual bypassing of these barriers may allow future genetic improvement of this key woody crop species.
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Affiliation(s)
- Kaifeng Ma
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, No. 35, Qinghua East Road, 100083 Beijing, PR China
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