Climate change and plant genomic plasticity

Abstract

Genome adaptation, driven by mutations, transposable elements, and structural variations, relies on plasticity and instability. This allows populations to evolve, enhance fitness, and adapt to challenges like climate change. Genomes adapt via mutations, transposable elements, DNA structural changes, and epigenetics. Genome plasticity enhances fitness by providing the genetic variation necessary for organisms to adapt their traits and survive, which is especially critical during rapid climate shifts. This plasticity often stems from genome instability, which facilitates significant genomic alterations like duplications or deletions. While potentially harmful initially, these changes increase genetic diversity, aiding adaptation. Major genome reorganizations arise from polyploidization and horizontal gene transfer, both linked to instability. Plasticity and restructuring can modify Quantitative Trait Loci (QTLs), contributing to adaptation. Tools like landscape genomics identify climate-selected regions, resurrection ecology reveals past adaptive responses, and pangenome analysis examines a species' complete gene set. Signatures of past selection include reduced diversity and allele frequency shifts. Gene expression plasticity allows environmental adaptation without genetic change through mechanisms like alternative splicing, tailoring protein function. Co-opted transposable elements also generate genetic and regulatory diversity, contributing to genome evolution. This review consolidates these findings, repositioning genome instability not as a mere source of random error but as a fundamental evolutionary engine that provides the rapid adaptive potential required for plant survival in the face of accelerating climate change.

Fig. 1

Plant genomic plasticity mechanisms under climate change-induced abiotic stress involve diverse genomic, genic, chromatin-epigenetic, and transcriptomic adaptations that collectively contribute to genome instability, novel gene functions, reversible epigenetic modifications, and transcriptomic changes, enhancing plant resilience and adaptation. The green arrows illustrate how each set of molecular mechanisms (top)—such as genome duplication or methylation—gives rise to a specific category of plasticity and its functional consequences (bottom). Genic plasticity refers to stress-induced changes occurring at the level of individual genes, leading to new genetic variations. Chromatin and epigenetic plasticity involves modifications to the chromatin structure that regulate gene accessibility and expression without altering the underlying DNA sequence. These responses are often rapid and reversible, allowing plants to adapt flexibly to environmental stress. Transcriptomic plasticity refers to changes at the RNA level that allow for flexible adaptation to the environment without any genetic change