Ecological significance of polyploidy in Brachypodium distachyon (Poaceae): influence on abiotic and biotic stress tolerance.
Polyploidization, i.e. the addition of a whole set of chromosomes to the genome, is a key issue in the study of the evolution of vascular plants. The origin and magnitude of variations in the ploidy level in plants have been studied during decades from different perspectives, including taxonomy and systematic, evolution, reproductive biology, conservation and, especially, genetic. However, in contrast to the considerable attention received by the genetic and genomic issues of polyploidization, the ecological and adaptive significance of plant polyploidization remains under-investigated. Similarly, whether differences in tolerance to biotic or abiotic stress are consequence of adaptive ecological divergence, or arise from nonadaptive ecological processes is still not well understood. Here, using as experimental model the species complex Brachypodium distachyon (Poaceae), we investigate the natural variation and way of selection of drought tolerance-related traits, and traits typically related to tolerance to pests, herbivores and plant competition among diploid and allotetraploid genotypes. Achievement of the goals here proposed will contribute in a major extent to answer the elusive question of the adaptive origin of polyploidy and to evaluate the ecological significance of polyploidization. This Project is funded by the Universidad de Jaén grant (Programa Propio de ayudas para la realizacion de Proyectos de Investigacion - UJA2011/12/38)
Natural selection and adaptive significance of candidates genes associated to drought resistance in the temperate grass Brachypodium distachyon (Poaceae)
Water stress is one of the main abiotic factors that limit the distribution and abundance of plants
and one of the major selective forces that promote local adaptation in plants. For these reasons,
understanding the mechanisms of how plants cope with water stress has been a recurrent and
central topic in plant ecology, plant physiology and evolution. In addition, from a socio-economic
view, drought also constitutes a major factor, negatively impacting crop growth and productivity
worldwide, especially in crop species that depend on a natural rainfall regime. Water use
efficiency (WUE) is a key trait intrinsically related to dehydration avoidance, which has a direct
impact on plant productivity. Intraspecific natural variation and the genetic architecture underlying
this variation is almost unknown. This proposed research will provide a comprehensive evolutionary analysis of the genetic basis of Brachypodium distachyon adaptation to dry environments, and will further shed light on the genome-level evolutionary patterns among other natural or crop temperate grass species. Specifically, we will address the following major goals: (1) to identify candidates genes related to variation in WUE through the analysis of the transcriptome; (2) to clone and sequence alleles candidates underlying variation in WUE, in order to transform the B. distachyon line Bd21, which genome has been recently sequenced; (3) to evaluate gene function and fitness of these selected candidate genes in experimental conditions. Finally, we propose to test the hypothesis that local adaptation is caused by the existence of genetic tradeoffs (antagonistic pleiotropy) at these
candidate genes. This project is funded by the Spanish Ministry of Economy and Competitiveness (Proyectos del Plan Nacional 2012 - CGL2012-30838)
Natural variation for drought tolerance in the grass Brachypodium distachyon, a new model species for ecological genomics.
By using an ecological genomic approach we investigate the evolutionary forces which shape natural genetic variation in this ecologically important trait across a naturally occurring water-stress gradient in the Iberian Peninsula. Also, we investigate the role of polyploidization as an adaptive response to aridity and drought. This project is funded by the European Commission through a Marie Curie Action (PIOFGA-2008-220983). Many advances in plant sciences have arisen from research on the mustard, Arabidopsis thaliana. However, relevance of this system for cereal crops of agricultural importance has been unclear, especially for yield and plant responses to diverse abiotic and biotic stresses. Especially challenging are agricultural species with complex genomes, or with low genome similarity to plant models. There is a real need for finding new plant models closer to plants with high socioeconomic interest that provide new answers to the present-day environmental challenges around the planet. For temperate grasses, a new plant model, Brachypodium distachyon, has recently emerged to address key long-term questions in plant functional genomics and ecology, such as, what is the origin of the variation of plant tolerance to drought or tolerance to pests. In addition, I consider approaches to screening natural variation, with the goal of identifying genomic regions underlying natural polymorphism in drought tolerance traits in this species using an eco-genomic perspective. Finally, I'm interested on how this information may be transferred and implemented in related grasses with socioeconomic interest.
Exploring Landscape complexity and extensification-intensification gradients effects on animal biodiversity and its ecosystem services in Andalusian olive agroecoystems
Land-change use, especially by agriculture intensification, is largely responsible for the decline in world-wide
biodiversity and its associated ecosystem services, what jeopardizes itself the sustainable agricultural yield. Recent studies have shown that, overall, CE incentive-based agro-environmental policies aimed at ameliorating such biodiversity decline (AES) have failed in such goal. Both theoretical and empirical studies suggest that biodiversity in agroecosystems is governed by synergistic effects of landscape complexity and agricultural management. It has been recentlyproposed that biodiversity increases non-linearly with landscape complexity, yet such relationship becomes asymptotic at intermediatehigh levels of complexity. Such relationship also seems to be affected by cultivation practices (organic vs. intensive agriculture). This theoretical frame, named the landscape moderation of biodiversity pattern and function hypotheses (s.l.), could explain the failure of AES policies given the decoupling between the scale at AES policies are aimed (local: stand) and the scale that is really important for biodiversity in agroecosystems (landscape). However, this conceptual frame has been developed mainly from studies conducted on annuals crops, whereas studies on woody crops are rare despite the huge economic and social importance in Europe of some of them such as grapevine and olive, apple, pear, cherry and almond trees, among others. This project aims to (1) explore the synergistic effects of landscape complexity and agricultural intensification on animal biodiversity and its associated ecosystem services of pest control, pollination of plants of agronomic interest, and seed dispersal in olive agricultural landscapes, one of the croplands with most socioeconomic, cultural and historical importance in Europe, which is further considered a refuge for biodiversity; and (2) conduct test of
the landscape moderation of biodiversity pattern and function hypotheses. In 20 olive localities of olive landscapes in Jaén, Córdoba, Granada and Málaga with presence of organic and intensive olive plantations we will proceed to a) characterize landscape complexity; (2) evaluate birds, ants, wild bees and pest natural enemies abundance; (3) assess avian seed dispersal and insectivory, olive damage by olive fly and moth pests, and the pollination service for Sinapis alba (a weed with oleaginous seed with potential for biodiesel); (4) explore the link between biodiversity, ecosystem services and landscape complexity; and (5) assess the AES effectiveness. Results of this project would be transferred to the olive oil production sector and to the biodiversity conservation management. More specifically, they will allow quantification of the amount of biodiversity and ecosystem services expected to be recovered from changing from intensive to extensive agriculture (or to be lost in opposite case) under a given landscape complexity, and to what extent the landscape modification induces changes in the ecosystem services by adding or removing semi-natural elements.(Proyectos del Plan Nacional 2015 - CGL2015-68963-C2-1-R)
Genetic and geographical variation in glucosinolate defensive compounds in natural populations of Boechera species (Brassicaceae). Combining field data and greenhouse experiments, we investigate the ecological and evolutionary mechanisms that promote and maintain the genetic variation in plant defences (resistance and tolerance traits) to insect herbivores. See the publication list for more details.
Ecology and evolution of seed dispersal in Helleborus foetidus (Ranunculaceae). Geographical variation in animal-plant interactions. During my Thesis I investigated the ant-seed dispersal mutualism in this species across a geographical gradient in Spain. The typical ecological consequences for the plant derived of this interaction varied notably among geographical regions and populations. Equally, the evolutionary impact for the plant of such interaction, estimated in terms of phenotypic selection on seed traits varied among the different stages of the seed dispersal process. See publications for more information.
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