Laboratory Center of Life Sciences, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Int J Mol Sci. 2021 Nov 9;22(22):12119. doi: 10.3390/ijms222212119.
Hydrogen sulfide (HS) is an important signaling molecule that regulates diverse cellular signaling pathways through persulfidation. Our previous study revealed that HS is involved in the improvement of rice drought tolerance. However, the corresponding enzymatic sources of HS and its regulatory mechanism in response to drought stress are not clear. Here, we cloned and characterized a putative () gene in rice, which encodes a protein possessing HS-producing activity and was named . Overexpression of results in enhanced HS production, persulfidation of total soluble protein, and confers rice drought tolerance. Further, we found that nitrate reductase (NR) activity was decreased under drought stress, and the inhibition of NR activity was controlled by endogenous HS production. Persulfidation of NIA2, an NR isoform responsible for the main NR activity, led to a decrease in total NR activity in rice. Furthermore, drought stress-triggered inhibition of NR activity and persulfidation of NIA2 was intensified in the overexpression line. Phenotypical and molecular analysis revealed that mutation of enhanced rice drought tolerance by activating the expression of genes encoding antioxidant enzymes and ABA-responsive genes. Taken together, our results showed the role of in modulating HS production and provided insight into HS-regulated persulfidation of NIA2 in the control of rice drought stress.
硫化氢（HS）是一种重要的信号分子，通过过硫化作用调节多种细胞信号通路。我们之前的研究表明，HS 参与了提高水稻耐旱性。然而，HS 的相应酶源及其对干旱胁迫的调节机制尚不清楚。在这里，我们克隆并鉴定了水稻中一个假定的（）基因，该基因编码一种具有 HS 产生活性的蛋白质，被命名为。过表达导致 HS 产生增加、总可溶性蛋白过硫化以及赋予水稻耐旱性。此外，我们发现干旱胁迫下硝酸还原酶（NR）活性降低，NR 活性的抑制受内源性 HS 产生的控制。NR 同工型 NIA2 的过硫化导致水稻中总 NR 活性降低。此外，在过表达系中，干旱胁迫触发的 NR 活性抑制和 NIA2 过硫化加剧。表型和分子分析表明，通过激活编码抗氧化酶和 ABA 响应基因的表达，突变增强了水稻的耐旱性。总之，我们的研究结果表明了在调节 HS 产生中的作用，并为 HS 调节 NIA2 过硫化在控制水稻干旱胁迫中的作用提供了新的认识。
