Zheng Hongxiang, Gao Yinping, Sui Yi, Dang Yingying, Wu Fenghui, Wang Xuemei, Zhang Fangning, Du Xihua, Sui Na
Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan, 250014, China.
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Theor Appl Genet. 2023 Jan;136(1):5. doi: 10.1007/s00122-023-04292-3. Epub 2023 Jan 19.
SbMYBHv33 negatively regulated biomass accumulation and salt tolerance in sorghum and Arabidopsis by regulating reactive oxygen species accumulation and ion levels. Salt stress is one of the main types of environmental stress leading to a reduction in crop yield worldwide. Plants have also evolved a variety of corresponding regulatory pathways to resist environmental stress damage. This study aimed to identify a SbMYBHv33 transcription factor that downregulates in salt, drought, and abscisic acid (ABA) in the salt-tolerant inbred line sorghum M-81E. The findings revealed that overexpression of SbMYBHv33 in sorghum significantly reduced sorghum biomass accumulation at the seedling stage and also salinity tolerance. Meanwhile, a heterologous transformation of Arabidopsis with SbMYBHv33 produced a similar phenotype. The loss of function of the Arabidopsis homolog of SbMYBHv33 resulted in longer roots and increased salt tolerance. Under normal conditions, SbMYBHV33 overexpression promoted the expression of ABA pathway genes in sorghum and inhibited growth. Under salt stress conditions, the gene expression of SbMYBHV33 decreased in the overexpressed lines, and the promotion of these genes in the ABA pathway was attenuated. This might be an important reason for the difference in growth and stress resistance between SbMYBHv33-overexpressed sorghum and ectopic expression Arabidopsis. Hence, SbMYBHv33 is an important component of sorghum growth and development and the regulation of salt stress response, and it could negatively regulate salt tolerance and biomass accumulation in sorghum.
SbMYBHv33通过调节活性氧积累和离子水平对高粱和拟南芥的生物量积累和耐盐性起负调控作用。盐胁迫是导致全球作物减产的主要环境胁迫类型之一。植物也进化出了多种相应的调控途径来抵抗环境胁迫的损害。本研究旨在鉴定一个在耐盐自交系高粱M-81E中受盐、干旱和脱落酸（ABA）下调的SbMYBHv33转录因子。研究结果表明，在高粱中过表达SbMYBHv33显著降低了幼苗期高粱的生物量积累以及耐盐性。同时，用SbMYBHv33对拟南芥进行异源转化也产生了类似的表型。SbMYBHv33在拟南芥中的同源基因功能缺失导致根更长且耐盐性增强。在正常条件下，SbMYBHV33过表达促进了高粱中ABA途径基因的表达并抑制生长。在盐胁迫条件下，过表达株系中SbMYBHV33的基因表达下降，ABA途径中这些基因的促进作用减弱。这可能是过表达SbMYBHv33的高粱与异位表达拟南芥在生长和抗逆性方面存在差异的一个重要原因。因此，SbMYBHv33是高粱生长发育以及盐胁迫反应调控的重要组成部分，并且它可能对高粱的耐盐性和生物量积累起负调控作用。
