Light Regulated Osa-miR169e Is Implicated during Priming under High Temperature Stress in Rice

Abstract

Plants face biotic and abiotic stresses during their entire life cycle, which leads to the loss in crop productivity. It has been shown that a relatively shorter exposure to heat stress, called priming, results in better adaptation of plants under subsequent stresses, which plants may face. While rice plants in nature often encounter high temperature stress conditions, the strategies to cope with those are poorly understood. We identified the involvement of microRNA pathways in the adaptation to heat stress (HS) at the physiological and molecular levels. It was observed that osa-miR169 levels are altered after HS and in response to light conditions. Its expression was also regulated by heat priming during anthesis and effectively responds to the successive exposure to high temperature stress during grain filling in rice. Osa-miR169 targets nuclear factor Y (NF-Y). We propose that osa-miR169: NF-Y regulatory module may be important for HS memory induced during high temperature priming and thus may serve to integrate stress responses with light regulated development. The future study in this direction will be useful to understand how plants acclimatize to the changing environment and thus help in generating stress tolerant crops.