百脉根伸展蛋白基因LjEXT1调控根系生长的功能分析OA

The extensin protein plays an important role in the formation of plant cell morphology,cell wall syn-thesis and root growth.To investigate the regulatory role of the LjEXT1 gene in root development,the function of the LjEXT1 gene in Lotus corniculatus was studied through bioinformatics prediction and plant genetic trans-formation methods.Gene expression analysis and transgenic identification were conducted using qRT-PCR,GUS histochemical staining and genomic PCR.Calcium white fluorescence staining and paraffin sectioning were used to observe root cell wall formation and cell structure and the root vitality was determined by the TTC method.The results showed that the LjEXT1 gene was mainly expressed in the roots and was highly conserved in Fabaceae plants,related to stress response and root development;overexpression of LjEXT1 delayed root differentiation by 3-6 days,inhibited root elongation and the formation of adventitious roots and reduced root vitality to 62.50％.The tissue sections and protoplast observations revealed that the cell walls of cells at the site of adventi-tious roots in transgenic plants were thickened by 20.42％and root cell wall formation was advanced by approxi-mately 24 hours.The gene expression analysis found that LjEXT1 affected the expression of cell wall regulation-related genes LjEXP,LjRLAF,and LjRHS.The study showed that the LjEXT1 gene negatively regulates root growth and could be related to promoting cell wall thickening.