毛白杨果胶甲酯酶PtoPME34-1调控植物抗旱性研究

Study of pectin methylesterase PtoPME34-1 regulating drought resistance in Populus tomentosa

为了探究林木植物中果胶甲酯酶PME的功能,本研究中,我们从毛白杨中克隆出拟南芥PME34的同源基因PtoPME34-1,阐述了该基因在毛白杨中的生物学功能.生物信息学分析表明,毛白杨PtoPME34-1基因与毛果杨PtrPME34-1序列相似性为100%,与拟南芥AtPME34序列相似性为93%.组织特异性表达分析显示PtoPME34-1基因在所有组织都有表达,在基部茎、木质部的表达量较高,在老叶表达量最低.蛋白亚细胞定位结果显示,绿色荧光蛋白GFP标记的PtoPME34-1-GFP融合蛋白定位在烟草叶片细胞壁.毛白杨PtoPME34-1基因过表达显著提高植株的抗旱性.毛白杨PtoPME34-1和PtoPME34-2基因的双突变体植株中果胶甲酯化程度升高,且植物抗旱性也显著增加.这些研究结果证实PtoPME34-1在调控植物生长发育和抗旱胁迫中发挥重要作用.

To explore the function of pectin methylesterase(PME) in forest plants, in this study, we cloned the Arabidopsis thaliana PME34 homologous gene PtoPME34-1 from Populus tomentosa, and elucidated the biological function of this gene in Populus tomentosa. Bioinformatics analysis shows that the similarity between the PtoPME34-1 gene of Populus tomentosa and the PtrPME34-1 of Populus tomentosa is 100%, and the similarity of the sequence with AtPME34 of Arabidopsis thaliana was 93%. Tissue specific expression analysis shows that PtoPME34-1 gene is expressed in all tissues, with higher expression levels in the basal stems and xylem, and the lowest expression level in the old leaves. The results of subcellular localization show that GFP-labeled PtoPME34-1-GFP fusion protein is localized in the cell wall of tobacco leaves. The overexpression of PtoPME34-1 gene significantly improved drought resistance of Populus tomentosa. The double mutants of Populus tomentosa PtoPME34-1 and PtoPME34-2 increased the degree of pectin methylesterification level and drought resistance. These results confirm that PtoPME34-1 plays an important role in regulating plant development and drought stress resistance.