Abstract: To investigate the effect of peach PpSnRK1 protein kinase on plant root growth，the seedling of peach[Prunus persica（L.）Batsch] was used as test material，the activity of SnRK1 in plants was regulated by exogenous application of salicylic acid and trehalose，and the effects on root structure and activity were observed. From the leaves of peach to the target gene of PpSnRKα（Ppa004347m），the PpSnRK1α-overexpressed Arabidopsis plants was obtained through Agrobacterium- mediated genetic transformation，the T3 lines was obtained through screening to observe the influence on the root structure，and auxin synthesis and transporter gene expression of the plant. The results showed that the SnRK1 enzyme activity and PpSnRK1α gene expression in peach seedling roots were up-regulated when the SnRK1 promoter salicylic acid was applied instantaneously or for a long time，and the root growth and root activity were positively regulated. However，the application of SnRK1 inhibitor trehalose inhibited the root growth and root activity. When salicylic acid and trehalose 1︰1（V︰V）was applied together，SnRK1 enzyme activity and PpSnRK1α gene expression were between the two treatments，and the inhibition of trehalose on root growth was partially alleviated. By observing the root of the PpSnRK1α-overexpressed Arabidopsis plants 4-1，4-2，4-3 homozygous lines，it can be seen that SnRK1 can increase the length and density of the roots，especially the number of lateral roots. By RT-qPCR technical analysis，the PpSnRK1α-overexpressed Arabidopsis three homozygous strain root，whether Auxin synthesis related genes（AtTAA1，AtYUC2，AtYUC6），and Auxin transport related genes（AtPIN1，AtPIN2，AtPIN3）expression quantity compared with wild type were significantly higher，and the root phenotype of exogenous applied 0.1 mg ? L-1 IAA wild type strain and three PpSnRK1α-overexpressed Arabidopsis plants is similar，root density，length，and lateral root number increased. This indicated that SnRK1’s effect on plant root system configuration was closely related to the auxin signaling pathway，which could positively regulate the synthesis and transport of auxin，and then positively regulate root growth，especially lateral root growth.

Key words: apple, exogenous gene, pollen；viability, tapetum, peach, SnRK1, the root structure, root activity；auxin