Author: fperfect

The TransRapid project investigates how transgenerational phenotypic plasticity may help plants respond rapidly to rising temperatures and recurrent heatwaves. The project compares Moricandia arvensis, a highly plastic Brassicaceae species with intermediate C3–C4 photosynthesis, with M. moricandioides, a related species that is less tolerant of thermal stress. It will integrate phenotyping, ecophysiology, transcriptomics, small RNAs, and DNA methylation to link molecular mechanisms with plant performance and reproductive success across multiple generations.

The TransRapid project—Transgenerational phenotypic plasticity as a mechanism of rapid adaptation to climate change—has been funded by the Spanish AEI to investigate how some plants may respond to an increasingly warmer climate and recurrent heatwaves. The research will be carried out by a team from the University of Granada and the CSIC Experimental Station of Arid Zones, led by Francisco Perfectti and Cristina Armas. It will combine functional ecology, plant physiology, genetics, epigenetics, and bioinformatics.

The project begins with a simple, though difficult, question: when a plant experiences high temperatures, can its offspring be better prepared to face similar conditions? This possibility is known as transgenerational phenotypic plasticity. It refers to changes in the development, physiology, or reproduction of one generation that are influenced by the environment experienced by its parents. These effects do not replace genetic evolution through natural selection, but they may help populations respond rapidly when environmental conditions change persistently

A Mediterranean plant model

TransRapid will use Moricandia arvensis as its main study species. This Brassicaceae species occurs in arid and semi-arid environments of southern Europe and North Africa. It belongs to the same family as agriculturally important plants such as cabbages, mustards, and radishes. In Mediterranean environments, M. arvensis can grow and reproduce both during the relatively mild and wet spring and during the much hotter and drier summer.

This capacity is associated with remarkable phenotypic plasticity: the same individual can modify multiple features of its leaves, flowers, physiology, and life cycle in response to environmental conditions. These include traits related to leaf economics, water-use efficiency, leaf anatomy, photorespiration, and reproduction. The species also has an intermediate C3–C4 photosynthetic metabolism, associated with mechanisms that may enhance the reassimilation of CO₂ released through photorespiration under warm conditions.

The project will also include Moricandia moricandioides, a related species with C3 photosynthesis and a less flexible phenotypic response. This comparison will allow researchers to test whether greater plasticity is associated with a better capacity to maintain performance and reproduction at high temperatures, without assuming in advance that every plastic response is necessarily adaptive.

Three interconnected objectives

The first objective is to describe how plasticity changes within and across generations under contrasting thermal conditions. Plants will be grown for several generations in controlled environments representing, on the one hand, benign spring-like conditions and, on the other, stressful high-temperature conditions. Researchers will measure reproductive, vegetative, functional, and photosynthetic traits, as well as indicators of growth and seed production. The experimental design will make it possible to analyse reaction norms—that is, how the phenotype of a given genotype changes across environments—and to test whether those responses are modified after repeated exposure to thermal stress.

The second objective will investigate the molecular mechanisms underlying these responses. Transcriptomic data will be generated to identify genes whose expression changes in response to heat stress and either persists or changes over multiple generations. The project will also examine regulatory small RNAs, including microRNAs, which can modulate the expression of other genes, as well as patterns of DNA methylation. Integrating these datasets will allow the team to explore associations between changes in gene expression, regulation by small RNAs, and epigenetic variation.

The third objective will focus on the functional and evolutionary consequences of these responses. The team will analyse plant size, growth, flowering onset, flower number, fruit production, and seed yield. It will also examine phenotypic integration, defined as the extent to which different traits covary with one another. High phenotypic integration may constrain the combinations of traits a plant can express, but it may also help stabilize sets of characteristics that are advantageous under recurrent stress.