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| Author(s): |
Mariana Vargas Cruz
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2019-05-22 |
| Examining board members: |
Anete Pereira de Souza;
Prianda Rios Laborda;
Simone Aparecida Vieira;
Karina Martins;
Rodrigo Cogni
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| Advisor: | Anete Pereira de Souza; Rafael Silva Oliveira |
| Abstract | |
Adaptation is often a product of environmental heterogeneity in the geographical space and has important implications for species' response to climate change. Species with wide geographical distribution represent an ideal model for the study of environmental selection, since different populations are subject to different selective pressures, which may shape genetic and phenotypic variations. We investigated the presence of evidences of environmental selection along the distribution of widespread plants from tropical to subtropical regions, typical of coastal zones - regions for which are predicted particularly striking effects of climate change over the course of this century. We integrated results from different approaches, such as ecophysiology and comparative transcriptomics, population genomics and genomic scans for selection in "Avicennia germinans" and "A. schaueriana" to investigate whether adaptive evolution is occurring in these two dominant trees in the Atlantic coast of South America. We observed a strong genetic structure in both species, as well as the presence of supposedly non-neutral divergences related to water and carbon balance, between plants from contrasting environments. Notably, in addition to phenotypic differences, we found in these two species nucleotide variations with signatures of positive selection in putative genes associated with key biological processes involved in abiotic stress tolerance. We provided evidences that tropical coastal plants may respond to the environmental heterogeneity existing throughout their distribution in factors, such as availability of water and light intensity. In addition, we present a case of rapid evolution of A. germinans in response to physiologic drought, with phenotypic changes and alterations in gene expression and nucleotide variation profiles. These findings help to understand how tropical trees survive under environmental changes, have implications for conservation and provide the basis for more realistic predictions on coastal plants responses to a rapidly changing climate (AU) | |
| FAPESP's process: | 13/26793-7 - Evolution of Avicennia schaueriana in face of historical and current climate changes: Functional genomics and ecophysiology |
| Grantee: | Mariana Vargas Cruz |
| Support Opportunities: | Scholarships in Brazil - Doctorate |