Phenotypic Effects of Salt and Heat Stress over Three Generations in Arabidopsis thaliana

Léonie Suter,Alex Widmer,Keqiang Wu

doi:10.1371/journal.pone.0080819

Abstract

Current and predicted environmental change will force many organisms to adapt to novel conditions, especially sessile organisms such as plants. It is therefore important to better understand how plants react to environmental stress and to what extent genotypes differ in such responses. It has been proposed that adaptation to novel conditions could be facilitated by heritable epigenetic changes induced by environmental stress, independent of genetic variation. Here we assessed phenotypic effects of heat and salt stress within and across three generations using four highly inbred Arabidopsis thaliana genotypes (Col, Cvi, Ler and Sha). Salt stress generally decreased fitness, but genotypes were differently affected, suggesting that susceptibility of A. thaliana to salt stress varies among genotypes. Heat stress at an early rosette stage had less detrimental effects but accelerated flowering in three out of four accessions. Additionally, we found three different modes of transgenerational effects on phenotypes, all harboring the potential of being adaptive: heat stress in previous generations induced faster rosette growth in Sha, both under heat and control conditions, resembling a tracking response, while in Cvi, the phenotypic variance of several traits increased, resembling diversified bet-hedging. Salt stress experienced in earlier generations altered plant architecture of Sha under salt but not control conditions, similar to transgenerational phenotypic plasticity. However, transgenerational phenotypic effects depended on the type of stress as well as on genotype, suggesting that such effects may not be a general response leading to adaptation to novel environmental conditions in A. thaliana.

Highlights

In the face of climate change, many organisms may be forced to adapt to novel, potentially challenging environmental conditions that may often exceed their typical range of reaction [1]
Transgenerational phenotypic effects depended on the type of stress as well as on genotype, suggesting that such effects may not be a general response leading to adaptation to novel environmental conditions in A. thaliana
Knowledge about molecular changes induced by salt stress is increasing [13,14] and a number of studies have examined the phenotypic consequences of saline conditions in A. thaliana [15,16,17]

Summary

Introduction

In the face of climate change, many organisms may be forced to adapt to novel, potentially challenging environmental conditions that may often exceed their typical range of reaction [1]. Organisms may have to migrate and track suitable habitats to escape extinction Changing environmental conditions, such as increasing temperature, may have important consequences for species diversity in natural ecosystems [2], and for crop production, since increasing temperatures can significantly decrease yield in many crop species [3]. Another major environmental factor affecting agriculture and natural vegetation is soil salinity, to date a problem in more than 100 countries worldwide [4]. A. thaliana is highly sensitive to saline conditions [18], remarkable differences between A. thaliana accessions have been reported [16,17]

Objectives

Methods

Results

Conclusion