Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Key Laboratory of Sugarcane Biotechnology and Genetic Improvement (Guangxi), Ministry of Agriculture and Rural Affairs & Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China.
Int J Mol Sci. 2022 Aug 23;23(17):9557. doi: 10.3390/ijms23179557.
The dehydration-responsive element-binding protein (DREB) is a subgroup member of the AP2/ERF family and actively participates in the response of plants to abiotic stress. Although genes have been studied in a variety of plant species, there are few reports of genes in sugarcane ( spp.). In this study, a novel full-length cDNA sequence of the gene was cloned from the hybrid ROC22, whose encoding protein contained only one AP2-conserved domain and was clustered into the DREB (A-2) subgroup. The diverse promoter elements in the gene and the accumulated transcripts of its homologous gene () in under drought stress suggest that the gene may play a role in drought response. In addition, reverse transcription quantitative PCR analysis showed that the expression level of the gene was upregulated in the root and leaf of ROC22 under polyethylene glycol, sodium chloride and abscisic acid (ABA) treatments. The yeast two-hybrid experiment demonstrated that ScDREB2B-1 had transcriptional self-activation activity. Compared with wild-type plants, the overexpression of the gene improved the drought tolerance of the transgenic by activating the ABA pathway to enhance the expression of the ABA-responsive gene () and ABA content, regulate the intracellular reactive oxygen species (ROS) level (enhance the transcripts of ROS synthase-related gene and the activities of catalase, peroxidase and superoxide dismutase) and increase the relative water content, proline content and expression level of osmotic stress-related genes ( and ). Collectively, our data indicate that is a stress-inducible and ABA-responsive transcription factor gene that responds to drought stress by regulating ABA signaling, ROS levels and stress-related gene expression. This study contributes to a better understanding of the biological function of , which could serve as a foundation for future resistance breeding in sugarcane.
脱水应答元件结合蛋白（DREB）是 AP2/ERF 家族的一个亚家族成员，积极参与植物对非生物胁迫的响应。尽管在多种植物物种中研究了 基因，但在甘蔗（ spp.）中很少有关于 基因的报道。在这项研究中，从杂交品种 ROC22 中克隆了一个新的全长 cDNA 序列的 基因，其编码的蛋白质仅含有一个 AP2 保守结构域，并被聚类到 DREB（A-2）亚组。 基因中多样化的启动子元件和其同源基因（）在干旱胁迫下在 中的转录本积累表明，该 基因可能在干旱响应中发挥作用。此外，反转录定量 PCR 分析表明，在聚乙二醇、氯化钠和脱落酸（ABA）处理下，ROC22 的根和叶中 基因的表达水平上调。酵母双杂交实验表明，ScDREB2B-1 具有转录自激活活性。与野生型植物相比， 基因的过表达通过激活 ABA 途径提高了转基因 的耐旱性，从而增强了 ABA 响应基因（）和 ABA 含量的表达，调节细胞内活性氧（ROS）水平（增强 ROS 合成酶相关基因的转录物和过氧化氢酶、过氧化物酶和超氧化物歧化酶的活性），并增加相对水含量、脯氨酸含量和渗透胁迫相关基因（和）的表达水平。总之，我们的数据表明， 是一个应激诱导和 ABA 响应的转录因子基因，通过调节 ABA 信号、ROS 水平和应激相关基因的表达来响应干旱胁迫。本研究有助于更好地理解 的生物学功能，为未来甘蔗的抗性育种奠定基础。
