Jiao Feng, Chen Yang, Zhang Dongdong, Wu Jinhua
College of Agriculture, Heilongjiang Bayi Agricultural University, Daqing 163319, China.
Plants (Basel). 2023 Aug 30;12(17):3121. doi: 10.3390/plants12173121.
Hexokinase (HXK) proteins catalyze hexose phosphorylation and are important for the sensing and signaling of sugar. In order to determine the roles played by HXKs in soybean growth and stress responsiveness, seventeen HXK genes () were isolated and analyzed. The phylogenic analysis and subcellular location prediction showed that GmHXKs were clearly classified into type A (GmHXK1-4) and type B (GmHXK5-17). There were similar protein structures and conserved regions in GmHXKs to the HXKs of other plants. An expression analysis of the genes in soybean organs or tissues demonstrated that and , , and were the dominant HXKs in all the examined tissues. In addition, salt, osmotic, and alkaline stress treatments dramatically increased the activity and transcripts of . There is the possibility that a type-B isoform (GmHXK15) plays a crucial role in soybean adaptation to alkali, as the expression levels of this isoform correlate well with the HXK enzyme activity. Based on an enzyme assay performed on recombinant plant HXK15 proteins expressed in , we found that GmHXK15 had functional HXK activities. A further analysis indicated that GmHXK15 specifically targeted the mitochondria, and the overexpression of the gene could significantly enhance the resistance of transgenic soybean to alkali stress. The present findings will serve as a basis for a further analysis of the function of the gene family.
己糖激酶（HXK）蛋白催化己糖磷酸化，对糖的感知和信号传导至关重要。为了确定HXKs在大豆生长和胁迫响应中所起的作用，分离并分析了17个HXK基因（）。系统发育分析和亚细胞定位预测表明，GmHXKs明显分为A类（GmHXK1 - 4）和B类（GmHXK5 - 17）。GmHXKs与其他植物的HXKs具有相似的蛋白质结构和保守区域。对大豆器官或组织中的基因进行表达分析表明，和，，以及是所有检测组织中的主要HXKs。此外，盐、渗透和碱性胁迫处理显著提高了的活性和转录本水平。一种B型异构体（GmHXK15）在大豆适应碱性环境中可能起关键作用，因为这种异构体的表达水平与HXK酶活性密切相关。基于对在中表达的重组植物HXK15蛋白进行的酶活性测定，我们发现GmHXK15具有功能性的HXK活性。进一步分析表明，GmHXK15特异性定位于线粒体，该基因的过表达可显著增强转基因大豆对碱性胁迫的抗性。本研究结果将为进一步分析基因家族的功能奠定基础。
