How Stress Facilitates Phenotypic Innovation Through Epigenetic Diversity

Abstract

Climate adaptation through phenotypic innovation will become the main challenge for plants during global warming. Plants exhibit a plethora of mechanisms to achieve environmental and developmental plasticity by inducing dynamic alterations of gene regulation and by maximizing natural variation through large population sizes. While successful over long evolutionary time scales, most of these mechanisms lack the short-term adaptive responsiveness that global warming will require. Here, we review our current understanding of the epigenetic regulation of plant genomes, with a focus on stress-response mechanisms and transgenerational inheritance. Field and laboratory-scale experiments on plants exposed to stress have revealed a multitude of temporally controlled, mechanistic strategies integrating both genetic and epigenetic changes on the genome level. We analyze inter- and intra-species population diversity to discuss how methylome differences and transposon activation can be harnessed for short-term adaptive efforts to shape co-evolving traits in response to qualitatively new climate conditions and environmental stress.

Epigenetic and transcriptional responses underlying mangrove adaptation to UV-B

“…The UV-B-induced TE reactivation in R. apiculata is consistent with the genome shock hypothesis ( McClintock, 1984 ). It is thought that stress-induced reactivation of TEs can help facilitate plant adaptation to extreme environments by either increasing genetic diversity or alternating gene regulatory networks ( Almojil et al., 2021 ; Srikant and Drost, 2020 ). Although we cannot directly measure the mutational effects of TE reactivation in R. apiculata , we did observe that the relaxation of TE epigenetic regulation is associated with the up-regulation of TE-adjacent loci.…”

The Underlying Nature of Epigenetic Variation: Origin, Establishment, and Regulatory Function of Plant Epialleles

“…However, although rare, there are some examples for transgenerational stress-induced epigenetic changes [65,66,81]. The duration, magnitude, and frequency of the applied stresses may influence the heritability of these changes [166]. The second factor affecting epiallele heritability is the genetic landscape of the locus.…”

Biogenesis, Trafficking, and Function of Small RNAs in Plants

“…After Arabidopsis is exposed to infection by biotrophic or necrotrophic pathogens, its progeny inherited resistance to biotrophic or necrotrophic pathogens across generations (López Sánchez et al, 2021). Trans-generational epigenetic inheritance of RdDM makes it possible to carry out plant genetic modification without changing the genotype and provides fundamental bases for the development of next-generation plant engineering approaches (Srikant and Drost, 2021). Because of its role in DNA methylation-mediated transgenerational inheritance, sRNA can not only be applied to develop retro-resistant crops, but also to prevent triploid arrest, that is, to restore seed activity after hybridization of plants with different chromosome numbers.…”