1
|
Mairal M, Šurinová M, Castro S, Münzbergová Z. Unmasking cryptic biodiversity in polyploids: origin and diversification of Aster amellus aggregate. Ann Bot 2018; 122:1047-1059. [PMID: 30107389 PMCID: PMC6266133 DOI: 10.1093/aob/mcy149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/18/2018] [Indexed: 05/14/2023]
Abstract
BACKGROUND AND AIMS The origin of different cytotypes by autopolyploidy may be an important mechanism in plant diversification. Although cryptic autopolyploids probably comprise the largest fraction of overlooked plant diversity, our knowledge of their origin and evolution is still rather limited. Here we study the presumed autopolyploid aggregate of Aster amellus, which encompasses diploid and hexaploid cytotypes. Although the cytotypes of A. amellus are not morphologically distinguishable, previous studies showed spatial segregation and limited gene flow between them, which could result in different evolutionary trajectories for each cytotype. METHODS We combine macroevolutionary, microevolutionary and niche modelling tools to disentangle the origin and the demographic history of the cytotypes, using chloroplast and nuclear markers in a dense population sampling in central Europe. KEY RESULTS Our results revealed a segregation between diploid and hexaploid cytotypes in the nuclear genome, where each cytotype represents a monophyletic lineage probably homogenized by concerted evolution. In contrast, the chloroplast genome showed intermixed connections between the cytotypes, which may correspond to shared ancestral relationships. Phylogeny, demographic analyses and ecological niche modelling supported an ongoing differentiation of the cytotypes, where the hexaploid cytotype is experiencing a demographic expansion and niche differentiation with respect to its diploid relative. CONCLUSIONS The two cytotypes may be considered as two different lineages at the onset of their evolutionary diversification. Polyploidization led to the occurrence of hexaploids, which expanded and changed their ecological niche.
Collapse
Affiliation(s)
- Mario Mairal
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Population Ecology, Czech Academy of Science, Průhonice, Czech Republic
- Department of Botany and Zoology, Stellenbosch University, Matieland, South Africa
- For correspondence. E-mail
| | - Mária Šurinová
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Population Ecology, Czech Academy of Science, Průhonice, Czech Republic
| | - Sílvia Castro
- Centre for Functional Ecology, Department of Life Sciences of the University of Coimbra and Botanic Garden of the University of Coimbra, Coimbra, Portugal
| | - Zuzana Münzbergová
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Population Ecology, Czech Academy of Science, Průhonice, Czech Republic
| |
Collapse
|
2
|
Duarte B, Goessling JW, Marques JC, Caçador I. Ecophysiological constraints of Aster tripolium under extreme thermal events impacts: Merging biophysical, biochemical and genetic insights. Plant Physiol Biochem 2015; 97:217-228. [PMID: 26485432 DOI: 10.1016/j.plaphy.2015.10.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/06/2015] [Accepted: 10/10/2015] [Indexed: 06/05/2023]
Abstract
Cold and heat waves are phenomenon that occurs in higher frequency and intensity due to global climate changes. Commonly cultivated crop species are crucially affected by extreme weather events, and therefore alternative crops - such as halophytes - gain in agricultural interest. While halophytes are potentially able to cope with temperature extremes on the long term exposure, effects of temporary events such as cold and heat waves are not yet described. In order to unveil the effects of these altered thermal environments, Aster tripolium plants were subjected to cold (9/5 °C) and heat (42/38 °C) waves regimes during 3 days and its photochemical and biochemical traits evaluated. In the potential cash crop A. tripolium cold waves induced the gene expression of dehydrins in order to counteract desiccation and thus to prevent oxidative stress. Regulatory proteins on the RNA maturation level (Maturase K) were highly expressed. Heat stress induced the gene expression of the cystein protease gene; most likely to degrade misfolded proteins temporary. Both thermal treatments decreased the photosynthetic efficiency and capacity, driven by a loss in the connectivity between PSII antennae. Nevertheless the light absorption capacity was unaffected due to an increased RC closure net rate. Cold wave-treated individuals showed a decrease in the carotenoid pigmentation, except auroxanthin. In cold wave treated individuals the overall peroxidase activity was significantly increased. Data suggest that exposure to both, cold and heat wave treatment decreased the ecophysiological capacity of A. tripolium.
Collapse
Affiliation(s)
- B Duarte
- MARE - Marine and Environmental Sciences Centre, Faculty of Sciences of the University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal.
| | - J W Goessling
- Marine Biological Laboratory, University of Copenhagen, 3000 Helsingor, Denmark
| | - J C Marques
- MARE - Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3000 Coimbra, Portugal
| | - I Caçador
- MARE - Marine and Environmental Sciences Centre, Faculty of Sciences of the University of Lisbon, Campo Grande, 1749-016 Lisbon, Portugal
| |
Collapse
|
3
|
Castro S, Loureiro J, Procházka T, Münzbergová Z. Cytotype distribution at a diploid-hexaploid contact zone in Aster amellus (Asteraceae). Ann Bot 2012; 110:1047-55. [PMID: 22887024 PMCID: PMC3448430 DOI: 10.1093/aob/mcs177] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 06/26/2012] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS The present study aims to assess the diversity and distribution of cytotypes of Aster amellus in central and eastern Europe, contributing with data to improve understanding of the evolutionary dynamics of the contact zone between diploids and hexaploids of this polyploid complex. METHODS Large-scale cytotype screening of 4720 individuals collected in 229 populations was performed using 4',6-diamidino-2-phenylindole (DAPI) flow cytometry. Fine-scale cytotype screening was performed in the mixed-ploidy population. Reproductive variables, such as number of florets per flower head, seed set and seedling emergence, as well as ploidy level of seeds and seedlings were recorded in this population. KEY RESULTS The diploid-hexaploid contact zone is large and complex, reaching the Czech Republic in the west, Austria in the south, Poland in the north-east and Romania in the extreme east of the surveyed areas. Most populations presented only one cytotype, either diploid or hexaploid. In several areas of the contact zone both cytotypes were found to grow in parapatry. One mixed-ploidy population of diploids and hexaploids was detected for the first time, but no signs of hybridization were detected. In this population, diploids had a significantly lower reproductive success, and significantly higher production of intercytotype offspring, being in reproductive disadvantage in comparison with hexaploids. CONCLUSIONS The contact zone of diploid and hexaploid A. amellus in central and eastern Europe seems to be highly dynamic and diffuse, with both primary and secondary contacts being possible. The obtained results suggest the origin of hexaploids through diploids, overall supporting previous hypotheses that this species is autopolyploid. Data from the only mixed-ploidy population detected so far suggest that the minority cytotype exclusion is an important evolutionary mechanisms driving the prevalence of single-cytotype populations, and thus contributing to the current distributional patterns of the cytotypes of A. amellus.
Collapse
Affiliation(s)
- S Castro
- CFE, Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
| | | | | | | |
Collapse
|
4
|
Pecchia P, Cammareri M, Malafronte N, Consiglio MF, Gualtieri MJ, Conicella C. Quinic acids from Aster caucasicus and from transgenic callus expressing a beta-amyrin synthase. Nat Prod Commun 2011; 6:1665-1669. [PMID: 22224284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
Several different classes of secondary metabolites, including flavonoids, triterpenoid saponins and quinic acid derivatives, are found in Aster spp. (Fam. Asteraceae). Several Aster compounds revealed biological as well as pharmacological activities. In this work, a phytochemical investigation of A. caucasicus evidenced the presence of quinic acid derivatives, as well as the absence of triterpene saponins. To combine in one species the production of different phytochemicals, including triterpenes, an Agrobacterium-mediated transformation of A. caucasicus was set up to introduce A. sedifolius beta-amyrin synthase (AsOXA1)-encoding gene under the control of the constitutive promoter CaMV35S. The quali-quantitative analysis of transgenic calli with ectopic expression of AsOXA1 showed, in one sample, a negligible amount of triterpene saponins combined with higher amount of quinic acid derivatives as compared with the wild type callus.
Collapse
Affiliation(s)
- Paola Pecchia
- CNR-IGV, Research Institute of Plant Genetics, Research Division Portici, Via Università 133, 80055 Portici, Italy
| | | | | | | | | | | |
Collapse
|
5
|
Pánková H, Münzbergová Z, Rydlová J, Vosátka M. The response of Aster amellus (Asteraceae) to mycorrhiza depends on the origins of both the soil and the fungi. Am J Bot 2011; 98:850-858. [PMID: 21613062 DOI: 10.3732/ajb.0900350] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PREMISE OF STUDY Previous studies testing pairwise interactions between plants, arbuscular mycorrhizal fungi (AMF) and soil have shown that the effectiveness of such interactions depends on the origins of the plants, soil, and AMF. Surprisingly, no study has yet looked at the three-way interaction between plants, soil, and AMF originating from the same and from different sites. Such knowledge could elucidate the determinants of local adaptations of plants and thus might help in various revegetation attempts. METHODS Six populations of the obligately mycorrhizal plant species Aster amellus from two isolated regions were combined with the soil and the AMF ecotype from their sites and plant growth were monitored over 16 months. KEY RESULTS For each combination of soil and native AMF, plants grown with their native AMF in their native soil had higher aboveground biomass, invested more to aboveground biomass and had higher numbers of fl ower heads than the other plants. The specifi city of the relationship among plant populations, AMF, and soil was also observed for percentage of root colonization. CONCLUSIONS The study extends our knowledge of the specifi c interaction between plants and AMF by demonstrating that the positive effect of native AMF occurs only when the plants are also grown in their native soil. Thus, when attempting to facilitate plant growth, we need to consider the origin of the plants, the soil, and the AMF, because all three components are adapted to each other.
Collapse
Affiliation(s)
- Hana Pánková
- Department of Botany, Faculty of Science, Charles University, 120 00 Prague 2, Czech Republic.
| | | | | | | |
Collapse
|
6
|
Abstract
Crosses between plants from different populations may result in heterosis or outbreeding depression. However, despite its importance for conservation, little is known about the spatial scale over which these effects may arise. To investigate the consequences of between-population crosses at two distinct spatial scales, we conducted reciprocal crosses between four populations from two regions in the rare perennial herb Aster amellus. We assessed seed set and offspring fitness in a common garden experiment. Overall, between-population crosses within regions (10 km) resulted in 8% lower seed set than within-population crosses, while between-region crosses (70 km) resulted in 17% higher seed set than within-population crosses. Moreover, offspring from between-population crosses produced 18% more flower heads than offspring from within-population crosses. We conclude that hybridisation between A. amellus plants from different populations did not lead to immediate outbreeding depression and, thus, could represent a valid conservation option to increase genetic diversity. Moreover, our results suggest that the distance between populations affects the outputs of between-population crosses and therefore needs to be taken into account when promoting gene flow between populations.
Collapse
Affiliation(s)
- J Raabová
- Department of Botany, National Museum, Průhonice, Czech Republic.
| | | | | |
Collapse
|
7
|
Confalonieri M, Cammareri M, Biazzi E, Pecchia P, Fevereiro MPS, Balestrazzi A, Tava A, Conicella C. Enhanced triterpene saponin biosynthesis and root nodulation in transgenic barrel medic (Medicago truncatula Gaertn.) expressing a novel beta-amyrin synthase (AsOXA1) gene. Plant Biotechnol J 2009; 7:172-82. [PMID: 19055609 DOI: 10.1111/j.1467-7652.2008.00385.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Triterpene saponins are a group of bioactive compounds abundant in the genus Medicago, and have been studied extensively for their biological and pharmacological properties. In this article, we evaluated the effects of the ectopic expression of AsOXA1 cDNA from Aster sedifolius on the production of triterpene saponins in barrel medic (Medicago truncatula Gaertn.). AsOXA1 cDNA encodes beta-amyrin synthase, a key enzyme involved in triterpene saponin biosynthesis. One of the four transgenic lines expressing AsOXA1 accumulated significantly larger amounts of some triterpenic compounds in leaf and root than did control plants. In particular, the leaf exhibited significantly higher levels of bayogenin, medicagenic acid and zanhic acid. The amounts of medicagenic acid and zanhic acid, which represent the core of the M. truncatula leaf saponins, were 1.7 and 2.1 times higher, respectively, than the amounts extracted from the control line. In root, the production of bayogenin, hederagenin, soyasapogenol E and 2beta-hydroxyoleanolic acid was increased significantly. The increase in the total amounts of triterpenic compounds observed in the leaves of transgenic lines correlated with the AsOXA1 expression level. Interestingly, the plants expressing AsOXA1 showed, under different growth conditions, improved nodulation when compared with the control line. Nodulation enhancement was also accompanied by a significant change in the soyasapogenol B content. Our results indicate that the ectopic expression of AsOXA1 in barrel medic leads to a greater accumulation of triterpene saponins and enhanced root nodulation.
Collapse
Affiliation(s)
- Massimo Confalonieri
- C.R.A. - Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, Viale Piacenza 29, 26900 Lodi, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Matoba H, Soejima A, Hoshi Y. Identification of parental genomes and genomic organization in Aster microcephalus var. ovatus. J Plant Res 2007; 120:585-93. [PMID: 17710369 DOI: 10.1007/s10265-007-0101-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2007] [Accepted: 05/10/2007] [Indexed: 05/16/2023]
Abstract
The karyotype of diploid Aster iinumae is morphologically similar to that of diploid Aster ageratoides var. ageratoides, however, its chromosome size is apparently smaller (S-type chromosomes versus L-type chromosomes, respectively). The hybrid origin of tetraploid Aster microcephalus var. ovatus (LS-type chromosomes) has previously been suggested by cytogenetics and chloroplast DNA (cp DNA) data. The cp DNA phylogeny also implies that the S-type chromosome is apomorphic, which means that genome size reduction occurred on the evolutionary way to A. iinumae. In this study, we have demonstrated that the chromosome size difference does not depend on the intensity of chromosome condensation but on the DNA content. The simultaneous genomic in situ hybridization (GISH) results show the similarity between S-type chromosomes of A. iinumae and A. microcephalus var. ovatus, and between L-type chromosomes of A. ageratoides and A. microcephalus var. ovatus, which provide additional evidence for A. microcephalus var. ovatus being a tetraploid amphidiploid produced by hybridization between S-type chromosomes and L-type chromosomes. The distribution patterns of Ty1-copia-like retrotransposons were similar in L- and S-type chromosomes. The copies of this retrotransposon dispersed uniformly on all chromosomes, and it is not yet apparent how the Ty1-copia-like retrotransposon affects the size difference between them.
Collapse
Affiliation(s)
- Hideyuki Matoba
- Department of Applied Biological Science, College of Bioresource Sciences, Nihon University, Kameino 1866, Fujisawa, Kanagawa 252-8510, Japan
| | | | | |
Collapse
|
9
|
Yamamoto R, Fujioka S, Iwamoto K, Demura T, Takatsuto S, Yoshida S, Fukuda H. Co-regulation of brassinosteroid biosynthesis-related genes during xylem cell differentiation. Plant Cell Physiol 2007; 48:74-83. [PMID: 17132633 DOI: 10.1093/pcp/pcl039] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
To understand the regulatory mechanisms of brassinosteroid (BR) biosynthesis in specific plant developmental processes, we first investigated the accumulation profiles of BRs and sterols in xylem differentiation in a Zinnia culture. The amounts of many substances in the late C28 sterol biosynthetic pathway to campesterol (CR), such as episterol and 24-methylenecholesterol, as well as those in the BR-specific biosynthetic pathway from CR to brassinolide (BL), were elevated in close association with tracheary element differentiation. Among them, 6-deoxotyphasterol (6-deoxoTY) accumulated to unusually high levels within cells cultured in tracheary element-inductive medium, while castasterone (CS) was not elevated either within or outside cells. To identify the molecular basis of this co-up-regulation of BRs and C28 sterols, we isolated Zinnia genes for the key enzymes of BR biosynthesis, ZeSTE1, ZeDIM, ZeDWF4, ZeCPD1 and ZeCPD2. RNA gel blot analysis of these genes indicated a coordinated increase in transcripts for ZeSTE1, ZeDIM, ZeDWF4 and ZeCPD1, and a tracheary element differentiation-specific increase in transcripts for ZeDWF4 and ZeCPD1. In situ hybridization experiments of ZeDWF4 and ZeCPD1 mRNAs revealed their preferential accumulation in procambium cells, immature xylem cells and xylem parenchyma cells. These results suggest that BR biosynthesis during tracheary element differentiation may be regulated by the coordinated regulation of broad sterol biosynthesis and specific regulation of BR biosynthesis, which occurs in part by elevated transcript levels of genes encoding BR biosynthetic enzymes, specifically ZeDWF4 and ZeCPD1. These data provide new insights into the regulation of BR biosynthesis and BR signaling during plant development.
Collapse
Affiliation(s)
- Ryo Yamamoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033 Japan.
| | | | | | | | | | | | | |
Collapse
|
10
|
Mandáková T, Münzbergová Z. Distribution and ecology of cytotypes of the Aster amellus aggregates in the Czech Republic. Ann Bot 2006; 98:845-56. [PMID: 16870643 PMCID: PMC2806165 DOI: 10.1093/aob/mcl165] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 02/24/2006] [Accepted: 06/05/2006] [Indexed: 05/11/2023]
Abstract
BACKGROUND AND AIMS Polyploidy is viewed as an important mechanism of sympatric speciation, but only a few studies have documented patterns of distribution and ecology of different cytotypes in their contact zone. Aster amellus agg. (Asteraceae) is one of the species with documented multiple ploidy levels. The aim of this study was to determine spatial distribution and ecology of two cytotypes, diploid (2n = 18) and hexaploid (2n = 54), of Aster amellus agg. at their contact zone in the Czech Republic. METHODS Root-tip squashes and flow cytometry were used to determine the ploidy of 2175 individuals from 87 populations. To test whether some differences in ecology between the two ploidy levels exist, in each locality relevés were recorded and abiotic conditions of the sites were studied by estimating potential direct solar radiation, Ellenberg indicator values and above-ground biomass. KEY RESULTS Together with diploid and hexaploids, minorite cytotypes (triploid, pentaploid and nonaploid) were found. No significant ecological differences between diploid and hexaploid cytotypes were found. In spite of this, no population consisting of both of the two basic cytotypes was found. CONCLUSIONS The results of this study show that the contact zone of diploid and hexaploid cytotypes in the Czech Republic is much more diffuse than indicated in previous records. Although populations of both cytotypes occur in close proximity (the closest populations of different cytotypes were 500 m apart), each individual population consists of only one basic ploidy level. This was unexpected since there are no clear differences in abiotic conditions between populations. Taken together with the absence of an intermediate tetraploid cytotype and with reference to published world distributional patterns of different ploidy levels, this suggests a secondary contact zone. Detailed genetic study is, however, necessary to confirm this.
Collapse
Affiliation(s)
- Terezie Mandáková
- Department of Botany, Charles University, Benátská 2, CZ-128 01, Prague, Czech Republic.
| | | |
Collapse
|
11
|
Abstract
Fourteen species of Aster were characterized for morphological traits of commercial interest, chromosome number and genetic diversity by AFLP markers to exploit this material not only for breeding purposes but also as source of pharmaceuticals. The variation observed among the Aster species for five morphological traits was summarized by means of discriminant analysis. Three significant canonical variables, accounting for about 96% of total variance, were mainly correlated with capitulum diameter, number of ligulae and leaf length. The morphological variation appeared related to ploidy level of the species. A diploid chromosome number ranging from 10 to 18 was evident in seven species whereas the other species are polyploids with variable chromosome numbers up to 52. The pollen production and stainability were quite variable among Aster species. Furthermore, seven species produced big pollen grains besides normally-sized ones, at a frequency ranging from 1 to 12%, possibly due to 2n pollen production. The possibility that evolution of Aster genus could be driven by 2n gametes and sexual polyploidization is discussed. Implications of 2n gametes for Aster breeding are also mentioned. AFLP analysis of the fourteen Aster species based on six primer combinations revealed a total number of 421 polymorphic amplified DNA fragments. The genetic similarities estimated between the Aster species, based on both shared and unique amplification products ranged from 0.335 to 0.604 across all species and revealed a geographically based clustering within the genus. The highest similarity was detected between A. alpinus and A. amellus with Eurasian origin.
Collapse
Affiliation(s)
- M Cammareri
- CNR-IGV, Research Institute of Plant Genetics, Research Division: Portici, Portici, Italy
| | | | | | | |
Collapse
|