Xing Xiaozheng, Tian Zengyuan, Yang Shuran, Wang Xiaomin, Xing Zhiyang, Wu Di, Zheng Shuting, Guo Yuqi
School of Life Sciences, Zhengzhou University, Kexue Road 100, Zhengzhou, 450001, China.
School of Agriclutural Sciences, Kexue Road 100, Zhengzhou, 450001, China.
BMC Genomics. 2025 Aug 7;26(1):731. doi: 10.1186/s12864-025-11864-8.
One important component of the cytokinin signaling pathway is the histidine phosphotransferase (HP), which plays an essential role in regulating downstream gene expression by transferring phosphate groups. The role of histidine phosphotransfer proteins (HPs) in sugar beets under abiotic and biotic stresses remains unclear. The results showed that the expression of BvHP4b in red beets increased in response to the exogenous hormone 6-BA. Transgenic Arabidopsis seedlings with heterologous expression of BvHP4 T3 lines (BvHP4-OE) displayed enhanced growth and resistance to Pst DC3000. Moreover, the expression of NPR1 and PRs was increased in the T3 transgenic lines compared to the control. Subcellular localization analysis revealed that BvHP4b primarily localized to the cell membrane. Transgenic red beets overexpressing BvHP4b (BvHP4b-OX lines) and bvhp4b mutant plants (KO lines) using CRISPR/Cas9 technology were generated respectively. The BvHP4b-OX lines showed enhanced taproot development, which was attributed to the altered expression of BvXTH33, BvCESA6, BvCDC2, and BvCEL1 genes. These lines also exhibited increased tolerance to Pst DC3000 by regulating synthesis of SA and modulating the expression of genes involved in plant immunity. In contrast, the KO plants were more susceptible to Pst DC3000 compared to the control plants. Furthermore, BvHP4b was shown to interact with BvCDC2 both in vivo and in vitro. Overall, this study suggests that the BvHP4b protein acts as a positive regulator, enhancing taproot enlargement and tolerance to Pst DC3000 in sugar beet plants.
细胞分裂素信号通路的一个重要组成部分是组氨酸磷酸转移酶（HP），它通过转移磷酸基团在调节下游基因表达中起关键作用。组氨酸磷酸转移蛋白（HPs）在甜菜非生物和生物胁迫下的作用仍不清楚。结果表明，红甜菜中BvHP4b的表达对外源激素6 - BA有响应而增加。具有BvHP4 T3系异源表达的转基因拟南芥幼苗（BvHP4 - OE）表现出增强的生长和对丁香假单胞菌番茄致病变种DC3000（Pst DC3000）的抗性。此外，与对照相比，T3转基因系中NPR1和病程相关蛋白（PRs）的表达增加。亚细胞定位分析表明，BvHP4b主要定位于细胞膜。分别利用CRISPR/Cas9技术构建了过表达BvHP4b的转基因红甜菜（BvHP4b - OX系）和bvhp4b突变体植株（KO系）。BvHP4b - OX系表现出主根发育增强，这归因于BvXTH33、BvCESA6、BvCDC2和BvCEL1基因表达的改变。这些株系还通过调节水杨酸（SA）的合成和调控植物免疫相关基因的表达，表现出对Pst DC3000的耐受性增加。相比之下，KO植株比对照植株更易受Pst DC3000侵染。此外，BvHP4b在体内和体外均被证明与BvCDC2相互作用。总体而言，本研究表明BvHP4b蛋白作为一种正向调节因子，增强了甜菜植株的主根膨大以及对Pst DC3000的耐受性。
