Mangrove adaptation in the environmental gradient of northern Brazilian coast and Amazon River mouth

• Grant number: 23/15656-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: March 01, 2024
• End date: February 29, 2028
• Field of knowledge: Biological Sciences - Genetics
• Principal Investigator: Gustavo Maruyama Mori
• Grantee: Gabriel Tofanelo Vanin
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

Local adaptation involves the process of natural selection resulting in an absolute increase in fitness and the prevalence of individuals with higher performance in their original environment. Gene flow has the potential to either promote or hinder local adaptation. Some species present remarkable dispersal ability over long distances, connecting spatially distant populations with implications for the adaptive process. Mangroves have this characteristic, mainly explained by propagules dispersal through ocean currents. In Brazil, divergent populations of species from two mangrove genera, Avicennia and Rhizophora, occur north and south of the easternmost tip of the country, due ocean current patterns and other drivers. For A. schaueriana, there is evidence that such low gene flow may have facilitated local adaptation in tropical and subtropical populations. However, even locally, on a scale of a few hundred meters, local adaptation can also occur. Separated by a road, two populations of A. germinans underwent intense selection resulting in distinct phenotypes and genotypes in a heterogeneous environment. However, at a regional scale, along the northern coast of Brazil, there is a scenario in which gene flow between locally thriving populations occurring across an environmental gradient remains unstudied. Moreover, in the west of this gradient, mangroves develop in waters with salinity close to zero, which is rare for mangroves, at the Amazon River mouth. Little is known about how these populations flourish across different environmental conditions and its underlying adaptive process. Thus, the objective of this project is to identify and characterize the adaptive processes that allowed mangrove trees to occupy diverse environments along the northern coast of Brazil. To achieve this, we will collect A. germinans and R. mangle leaf and propagules samples along the northern coast of Brazil. We will use a population genomics approach to describe the genetic structure of populations, infer gene flow between them, and identify loci under selection. Propagules will be cultivated in a common garden to assess, in a homogeneous environment, how populations respond physiologically and molecularly using ecophysiology measurements and gene expression through RNA-seq. Evidence of local adaptation will be obtained through evidence triangulation from these three approaches (genomics, transcriptomics and ecophysiology). This proposal will provide novel insights into how mangroves respond to current environments, enabling more accurate predictions of their response in future environmental scenarios.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VANIN, GABRIEL; LACERDA, EDUARDO; MORI, GUSTAVO. Drivers of mangrove area change and suppression in Brazil from 2000 to 2020. Conservation Biology, v. N/A, p. 11-pg., 2024-12-20. (23/15656-0, 22/02804-9)