Wang Peijie, Wu Xiaojuan, Li Nan, Nie Hushuai, Ma Yu, Wu Juan, Zhang Zhicheng, Ma Yanhong
Agricultural College, Faculty of Agricultural College, Inner Mongolia Agricultural University, Hohhot, 010019, China.
Institute of Ulanqab Agricultural and Forestry Sciences, Ulanqab, 012000, China.
BMC Plant Biol. 2025 Jan 4;25(1):14. doi: 10.1186/s12870-024-06010-7.
Drought stress is a major environmental constraint affecting crop yields. Plants in agricultural and natural environments have developed various mechanisms to cope with drought stress. Identifying genes associated with drought stress tolerance in potato and elucidating their regulatory mechanisms is crucial for the breeding of new potato germplasms. The bHLH transcription factors involved play crucial roles not only in plant development and growth but also in responsesresponse to abiotic stress.
In this study, the StbHLH47 gene, which is highly expressed in potato leaves, was cloned and isolated. Subcellular localization assays revealed that the gene StbHLH47 performs transcriptional functions in the nucleus, as evidenced by increased malondialdehyde (MDA) content and relative conductivity under drought stress. These findings indicate that overexpressing plants are more sensitive to drought stress. Differential gene expression analysis of wild-type plants (WT) and plants overexpressing StbHLH47 (OE-StbHLH47) under drought stress revealed that the significantly differentially expressed genes were enriched in metabolic pathways, biosynthesis of various plant secondary metabolites, biosynthesis of metabolites, plant hormone signal transduction, mitogen-activated protein kinase (MAPK) signalling pathway-plant, phenylpropanoid biosynthesis, and plant‒pathogen interactions. Among these pathways, the phenylalanine and abscisic acid (ABA) signal transduction pathways were enriched in a greater number of differentially expressed genes, and the expression trends of these differentially expressed genes (DEGs) were significantly different between WT and OE-StbHLH47. Therefore, it is speculated that StbHLH47 may regulate drought resistance mainly through these two pathways. Additionally, RT‒qPCR was used for fluorescence quantification of the expression of StNCED1 and StERD11, which are known for their drought resistance, and the results revealed that the expression levels were much lower in OE-StbHLH47 than in WT plants.
RNA-seq, RT‒qPCR, and physiological index analyses under drought conditions revealed that overexpression of the StbHLH47 gene increased the sensitivity of potato plants to drought stress, indicating that StbHLH47 negatively regulates drought tolerance in potato plants. In summary, our results indicate that StbHLH47 is a negative regulator of drought tolerance and provide a theoretical basis for further studies on the molecular mechanism involved.
干旱胁迫是影响作物产量的主要环境限制因素。农业和自然环境中的植物已形成多种机制来应对干旱胁迫。鉴定马铃薯中与耐旱性相关的基因并阐明其调控机制对于培育新的马铃薯种质至关重要。所涉及的bHLH转录因子不仅在植物发育和生长中起关键作用，而且在对非生物胁迫的响应中也起关键作用。
在本研究中，克隆并分离了在马铃薯叶片中高表达的StbHLH47基因。亚细胞定位分析表明，StbHLH47基因在细胞核中发挥转录功能，干旱胁迫下丙二醛（MDA）含量和相对电导率增加证明了这一点。这些结果表明，过表达植株对干旱胁迫更敏感。对干旱胁迫下的野生型植株（WT）和过表达StbHLH47的植株（OE-StbHLH47）进行差异基因表达分析，结果显示，显著差异表达的基因富集在代谢途径、各种植物次生代谢物的生物合成、代谢物的生物合成、植物激素信号转导、丝裂原活化蛋白激酶（MAPK）信号通路-植物、苯丙烷类生物合成以及植物-病原体相互作用中。在这些途径中，苯丙氨酸和脱落酸（ABA）信号转导途径富集了更多的差异表达基因，并且这些差异表达基因（DEGs）在WT和OE-StbHLH47之间的表达趋势显著不同。因此，推测StbHLH47可能主要通过这两条途径调节抗旱性。此外，使用RT-qPCR对已知具有抗旱性的StNCED1和StERD11的表达进行荧光定量，结果显示，OE-StbHLH47中的表达水平远低于WT植株。
干旱条件下的RNA测序、RT-qPCR和生理指标分析表明，StbHLH47基因的过表达增加了马铃薯植株对干旱胁迫的敏感性，表明StbHLH47负向调节马铃薯植株的耐旱性。总之，我们的结果表明StbHLH47是耐旱性的负调节因子，并为进一步研究其涉及的分子机制提供了理论基础。
