Fang Qilong, Wu Di, Sun Hu, Wang Luyao, Liu Yuping, Mei Wenfeng, Guo Huiyan
College of Forestry Shenyang Agricultural University Shenyang China.
The Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province Shenyang Agricultural University Shenyang China.
Plant Direct. 2024 Dec 17;8(12):e70029. doi: 10.1002/pld3.70029. eCollection 2024 Dec.
Basic helix-loop-helix (bHLH) proteins comprise a large family of transcription factors that are involved in plant growth and development, as well as responses to various types of environmental stress. (birch) is a pioneer tree species in secondary forest that plays a key role in maintaining ecosystem stability and forest regeneration, but few bHLHs involved in abiotic stress responses have been unveiled in birch. In this study, nine BpbHLH TFs related to stress responses in the birch genome were identified. Quantitative real-time polymerase chain reaction (RT-PCR) analysis indicated that the expression of these TFs can be induced by salt stress, and the expression of was higher than that of other genes. Particle bombardment analysis revealed that BpbHLH1 was localized to the nucleus. Yeast transformation found that BpbHLH1 has transcriptional activation activity. We generated -overexpressing and silencing transgenic birch plants and subjected them to salt stress analysis. can enhance the salt tolerance of birch plants by increasing the reactive oxygen species scavenging ability and inhibiting cell death. Yeast one-hybrid, ß-glucuronidase, and chromatin immunoprecipitation assays revealed that BpbHLH1 can regulate the expression of target genes involved in stress resistance by binding to the E-box-1, E-box-2 and G-box elements in their promoters. The results of this study enhanced our understanding of the salt tolerance conferred by BpbHLH TFs in and identified useful genes for the breeding of novel birch germplasm.
基本螺旋-环-螺旋（bHLH）蛋白构成了一个庞大的转录因子家族，它们参与植物的生长发育以及对各种环境胁迫的响应。白桦是次生林中的先锋树种，在维持生态系统稳定性和森林更新中起着关键作用，但白桦中参与非生物胁迫响应的bHLH蛋白却鲜有报道。在本研究中，我们在白桦基因组中鉴定出了9个与胁迫响应相关的BpbHLH转录因子。定量实时聚合酶链反应（RT-PCR）分析表明，这些转录因子的表达可被盐胁迫诱导，且其中一个基因的表达高于其他基因。粒子轰击分析表明BpbHLH1定位于细胞核。酵母转化实验发现BpbHLH1具有转录激活活性。我们构建了过表达和沉默该基因的转基因白桦植株，并对其进行盐胁迫分析。该基因可通过提高活性氧清除能力和抑制细胞死亡来增强白桦植株的耐盐性。酵母单杂交、β-葡萄糖醛酸酶和染色质免疫沉淀分析表明，BpbHLH1可通过结合其启动子中的E-box-1、E-box-2和G-box元件来调控参与抗逆的靶基因的表达。本研究结果加深了我们对白桦中BpbHLH转录因子赋予耐盐性的理解，并为新型白桦种质的培育鉴定出了有用的基因。
