Crosstalk between hydrogen peroxide and nitric oxide mediates priming‐induced drought tolerance in wheat
Xiao Wang, Qing Li, Mengxiang Yang, Zhang Jia, Mei Huang, Jian Cai, Qin Zhou, Tingbo Dai, Bernd Wollenweber, Dong Jiang
Abstract
Abstract Drought is a limiting factor for wheat production. Nitric oxide (NO) and hydrogen peroxide (H 2 O 2 ) are key signalling molecules produced in response to drought stress. Drought priming is a promising strategy for enhancing drought tolerance. Here, the roles of NO and H 2 O 2 in drought priming were investigated. The results showed that the scavengers of NO or H 2 O 2 reduced the effects of priming‐induced tolerance to drought stress during seedling and grain filling stages. Drought priming induced the production of H 2 O 2 and NO, suggesting that H 2 O 2 and NO were involved in priming‐induced drought tolerance and that the synthesis of H 2 O 2 could be related to respiratory burst oxidase homologues (RBOH). Further, nitrate reductase (NR) activity was not the unique source for NO production. The elevated production of NO in the primed plants was blocked by scavengers of both H 2 O 2 and NO, whereas the H 2 O 2 concentration was not affected by a scavenger of NO. Osmolyte accumulation induced by drought priming was partly inhibited by the removal of NO, but was higher than in non‐primed plants. NO worked downstream of H 2 O 2 ‐mediated the accumulation of proline and glycine‐betaine in primed plants under drought stress during grain filling. The results increase our understanding of the roles of H 2 O 2 and NO in priming‐induced drought tolerance in wheat.