S11 - Session P3 - Unraveling drought tolerance in pepper plants through RNA-seq analysis

Authors: Yaiza Padilla *, Ramón Gisbert Mullor, Eduardo Bueso, Salvador López Galarza, Angeles Calatayud

Among abiotic stresses affecting crops, water scarcity rises as a major problem in many parts of the world, causing important losses in productivity every year (Ashraf, 2010). Grafting, meaning the fusion between the root and the shoot from different plants, emerges as a sustainable and eco-friendly technique that can be used to face this threat, particularly in Solanaceae species, usually cultivated in areas suffering from water starvation (Fullana-Pericas et al., 2020; Gisbert-Mullor et al., 2020, Rouphael et al., 2018). Little has been published about the processes underlying grafted plants tolerance to water stress, especially in pepper plants. This work aimed to unravel tolerance mechanisms by studying the transcriptomic profile of two pepper rootstocks: NIBER®, designed to cope with water stress, and A10, sensitive to water stress. Plants were exposed to 4% polyethylene glycol in hydroponic culture for 24h to induce water stress and RNA-sequencing was performed with root samples. Differences among rootstocks in the transcriptomic profile for genes related to ROS detoxification, stomata control, sugar metabolism, polyamines regulation and hormonal network were found. These results suggest differential strategies when facing water stress that lead to tolerance (NIBER®) or sensitivity (A10). Therefore, these DEGs can be employed as biomarkers to select tolerant rootstocks and use them in grafting under water stress conditions.