Alam Mohammad Shah, Kong Jiarui, Tao Ruofu, Ahmed Temoor, Alamin Md, Alotaibi Saqer S, Abdelsalam Nader R, Xu Jian-Hong
Institute of Crop Science, Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou 310058, China.
Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China.
Plants (Basel). 2022 Apr 27;11(9):1184. doi: 10.3390/plants11091184.
Salinity stress is one of the most prominent abiotic stresses that negatively affect crop production. Transcription factors (TFs) are involved in the absorption, transport, or compartmentation of sodium (Na) or potassium (K) to resist salt stress. The basic helix-loop-helix (bHLH) is a TF gene family critical for plant growth and stress responses, including salinity. Herein, we used the CRISPR/Cas9 strategy to generate the gene editing mutant to investigate the role of in rice under salt stress. The A nucleotide base deletion was identified in the mutant (A91). Exposure of the A91 under salt stress resulted in a significant increase in the shoot weight, the total chlorophyll content, and the chlorophyll fluorescence. Moreover, high antioxidant activities coincided with less reactive oxygen species (ROS) and stabilized levels of MDA in the A91. This better control of oxidative stress was accompanied by fewer Na but more K, and a balanced level of Ca, Zn, and Mg in the shoot and root of the A91, allowing it to withstand salt stress. Furthermore, the A91 also presented a significantly up-regulated expression of the ion transporter genes (, , and ) in the shoot when exposed to salt stress. These findings imply that the might play the role of a negative regulator of salt stress, which will help to understand better the molecular basis of rice production improvement under salt stress.
盐胁迫是对作物生产产生负面影响的最突出的非生物胁迫之一。转录因子（TFs）参与钠（Na）或钾（K）的吸收、运输或区室化以抵抗盐胁迫。基本螺旋-环-螺旋（bHLH）是一个对植物生长和胁迫反应（包括盐胁迫）至关重要的TF基因家族。在此，我们使用CRISPR/Cas9策略生成基因编辑突变体，以研究其在水稻盐胁迫下的作用。在突变体（A91）中鉴定到一个A核苷酸碱基缺失。在盐胁迫下A91的地上部重量、总叶绿素含量和叶绿素荧光显著增加。此外，A91中高抗氧化活性与较少的活性氧（ROS）和稳定水平的丙二醛（MDA）同时出现。对氧化胁迫的这种更好控制伴随着A91地上部和根部较少的Na但较多的K，以及Ca、Zn和Mg的平衡水平，使其能够耐受盐胁迫。此外，A91在盐胁迫下地上部离子转运蛋白基因（、和）的表达也显著上调。这些发现表明可能在盐胁迫中起负调控因子的作用，这将有助于更好地理解水稻在盐胁迫下产量提高的分子基础。
