关键词: 非生物逆境, 逆境锻炼, 当代锻炼, 跨代锻炼, 生理机制, 信号调控机制

Abstract:

Abiotic stress factors, including heat stress, cold stress, drought stress, waterlogging stress etc., are the limiting factors for plant growth and crop production. Moreover, the frequency, extent and duration of abiotic stresses have predicted to be increased with global climate change. Therefore, improving crops resistance to abiotic stress or finding strategy to reduce the adverse effects of abiotic stress on crop yield and quality is of great significance for ensuring stable crop production and food security. “Priming” by exposing plants to moderate stress in the early growth stage can induce plant resistance to a later severe stress episode which happened during critical stage of the plant growth. The priming is an adaptive strategy that primed plants could effectively mount a faster and/or stronger defense response and actively improve the defensive capacity of plants under stress, compared with non-primed plants. According to the reoccurred stress types, the priming can be generally separated to four types, including in-generational stress tolerance (the priming stimulus and the stress occurred at later stage are the same stress type), intra-generational cross tolerance (the priming stimulus and the stress occurred at later stage are different stress types), transgenerational stress tolerance (the priming stimulus and the stress occurred at next generations are the same stress type), and transgenerational cross tolerance (the priming stimulus and the stress occurred at next generations are different stress types). In this review, the main physiological mechanisms were discussed, including plant photosynthetic response mechanism, antioxidant mechanism, and osmotic regulation, signal transduction mechanisms (plant hormones, Ca²⁺, hydrogen peroxide, nitric oxide, etc.), and epigenetic modification mechanisms (DNA methylation, histone modification, etc.). Then, the perspectives for the further research on understanding the underlying mechanisms of stress priming and the application of priming effects in the crop production were suggested. After revealing the mechanisms of priming, the candidate genes and proteins which play key regulatory roles in the acquisition of crop stress tolerance are found. And then, we can stimulate the related genes and protein expression which can actively induce the formation of stress tolerance in the critical crops growth stage, thereby effectively alleviating the adverse effects of abiotic stress on crop yield during the critical stage, which is meaningful for the crop production.

Key words: abiotic stress, priming, intra-generational priming, transgenerational priming, physiological mechanisms, signal transduction mechanisms