Influence of abiotic stresses in root regeneration

Resumen

Plants possess outstanding regenerative capabilities, and the root system is no exception. Root growth is centred around the root apical meristem (RAM), which houses the stem cell niche (SCN) and, with in it, the Quiescent Centre (QC) organizer. Lesions to the meristem trigger a regenerative process involving hormonal changes, transitions of cell identity and activation of key stemness regulators, ultimately leading to the restoration of a new root SCN and meristem. How abiotic stresses influence root regeneration is poorly understood. Recent studies have showed that moderate cold exposure has a positive effect on the root tip regeneration process.

This study investigates the hypothesis that cold is integrated into canonical developmental networks that regulate regeneration. Specifically, regeneration may be directly influenced by cold response regulators such as C-BINDING FACTOR 3 (CBF3), in a process modulated by stead temperatures (spring conditions) and temperature fluctuations (cold snaps and warm spells). Our results show that moderate cold slows down development and enhances early WOX5 expression patterns in the QC alongside CBF3. Furthermore, cold accelerates morphological root regeneration and promotes stem cell induction in a CBF3-dependent manner, while warm spell represses this latter effect. Preliminary real-time quantitative PCR data indicate that cold influences the expression of key stem cell and regeneration regulators, suggesting increased stem cell induction efficiency.