Investigating on intergenerational drought stress memory in tomato (Solanum lycopersicum).

Drought is one of the most significant environmental stresses affecting plant growth, productivity, and agricultural sustainability, particularly under the increasing pressures of climate change. Plants have evolved complex adaptive mechanisms to cope with recurrent stress conditions, including the development of stress memory, whereby prior exposure to stress enhances subsequent responses. Emerging evidence suggests that epigenetic modifications and transcriptional regulation play crucial roles in establishing and maintaining such memory, which may even be transmitted across generations. This thesis investigates the potential existence of intergenerational drought stress memory in tomato (Solanum lycopersicum) by examining the expression patterns of selected drought memory-associated genes. The study focuses on the progeny (S1 generation) of parental tomato plants (S0 generation) previously exposed to drought and recovery cycles. Gene expression analysis was conducted using quantitative PCR (RT-qPCR) on leaf tissues collected at two developmental stages, designated as Time Point 1 (T1) and Time Point 2 (T2). Candidate genes analysed included AP2B3, HHO2, HHO6, ABIG1, and NFYA which were selected through RNA-seq datasets, these genes are known to participate in drought signalling, ABA-mediated responses, transcriptional regulation, and stress adaptation pathways. By evaluating transcript accumulation patterns in S1 of drought-exposed plants, this research aims to determine whether parental stress experiences induce heritable molecular changes indicative of intergenerational stress memory. The findings are expected to contribute to a deeper understanding of the transcriptional and epigenetic mechanisms underlying drought adaptation in tomato. Such knowledge may support future breeding strategies aimed at developing crop varieties with enhanced resilience to water scarcity and climate change.