The State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.
The Key Laboratory of Plant Molecular Breeding of Guangdong Province, College of Agriculture, South China Agricultural University, Guangzhou, China.
BMC Genomics. 2022 Jul 22;23(1):529. doi: 10.1186/s12864-022-08744-w.
MYB transcription factor (TF) is one of the largest families of TFs in plants and play essential roles in plant growth and development, and is involved in responses to biological and abiotic stress. However, there are few reports on GsMYB7 gene in soybean under aluminum acid stress, and its regulatory mechanism remains unclear.
The GsMYB7 protein is localized in the nucleus and has transcriptional activation ability. Quantitative real-time PCR (qRT-PCR) results showed that GsMYB7 held a constitutive expression pattern rich in roots. When AlCl concentration was 25 µM, the total root surface area (SA) of GsMYB7 transgenic lines were 34.97% higher than that of wild-type Huachun 6 (HC6). While the accumulation of Al in root tip of transgenic plants after aluminum treatment was 17.39% lower than that of wild-type. RNA-sequencing analysis indicated that over 1181 genes were regulated by GsMYB7 and aluminum stress. Among all the regulated genes, the expression levels of glutathione peroxidase, protein kinase, cytochrome and other genes in the transgenic lines were significantly higher than those in wild type by acidic aluminum stress. The bioinformatics and qRT-PCR results showed that 9 candidate genes were induced under the treatments of acidic aluminum stress which were indirectly and/or directly regulated by GsMYB7. After AlCl treatments, the transcripts of these genes in GsMYB7 transgenic seedlings were significantly higher than those of wide-type HC6.
The results suggested that GsMYB7 may enhance soybean tolerance to acidic aluminum stress by regulating the downstream genes.
MYB 转录因子（TF）是植物中最大的 TF 家族之一，在植物生长发育中发挥着重要作用，并参与生物和非生物胁迫的响应。然而，关于大豆在铝酸胁迫下的 GsMYB7 基因的报道较少，其调控机制尚不清楚。
GsMYB7 蛋白定位于细胞核内，具有转录激活能力。定量实时 PCR（qRT-PCR）结果表明，GsMYB7 在根系中呈组成型表达模式。当 AlCl3 浓度为 25 µM 时，GsMYB7 转基因系的总根表面积（SA）比野生型华春 6（HC6）高 34.97%。而在铝处理后，转基因植物根尖的铝积累量比野生型低 17.39%。RNA-seq 分析表明，GsMYB7 及其铝胁迫调控超过 1181 个基因。在所有受调控的基因中，在酸性铝胁迫下，谷胱甘肽过氧化物酶、蛋白激酶、细胞色素等基因在转基因系中的表达水平明显高于野生型。生物信息学和 qRT-PCR 结果表明，9 个候选基因在酸性铝胁迫下受到 GsMYB7 的诱导，这些基因受 GsMYB7 的间接和/或直接调控。在 AlCl3 处理后，这些基因在 GsMYB7 转基因幼苗中的转录本明显高于野生型 HC6。
结果表明，GsMYB7 可能通过调控下游基因增强大豆对酸性铝胁迫的耐受性。
