Analysis Of Pr Protein Family And Functional Study Of PR10 And PR17 In Cotton

Pathogenesis-related proteins are induced by adversity stress, playing an important role in plant disease resistance reaction. Verticillium wilt caused by Verticillium dahliae is the “cancer” for cotton. In order to study the role of PR proteins in disease resistance, and to provide candidate genes for resistance breeding in cotton, PRs are chosen by being compared with the Cotton D genome based on a full-length c DNA library of Gossypium barbadense Pima90-53 under Verticillium dahliae stress. Quantitative real-time PCR is used to analyze the expression of several genes under V. dahliae stress and hormones. Furthermore, the Verticillium wilt resistance of silenced plants was analysis; the physiological structure and the influence to other PRs were also detected in the silenced cotton seedlings. The main results were as follows:1. Fifty genes belonging to 9 families were chosen from the full-length c DNA library of Gossypium barbadense Pima90-53 under V. dahliae stress. 3 PR1 s, 1 PR2, 2 PR3 s, 7 PR4 s, 12 PR5 s, 2 PR8 s, 19 PR9 s, 3 PR10 s, and 1 PR17 were included.2. In Pima90-53, PR1, PR4, PR8, PR10, and PR17 were highly induced by V. dahliae, while PR2, PR3, PR5 and PR9 could also be induced. In CCRI8, PR1, PR3, PR8, PR9, PR10 and PR17 were induced by V. dahliae, while the expression of PR2, PR4 and PR5 were inhibited. Indicating that, PR proteins response to the V. dahlia inoculation in cotton.3. In Pima90-53, PR1, PR4, PR8, and PR17 could be induced by SA, ET, and Me JA. PR10 could also be induced by SA and ET, but was inhibited by Me JA. In CCRI8, PR1、PR4 and PR17 were induced by SA, while PR8 and PR10 were inhibited; PR4, PR8, PR10 and PR17 could be induced by ET, while PR1 was inhibited; PR1, PR4 and PR17 could be induced by Me JA, while PR8 and PR10 were inhibited. Based on the expression of these genes, it could be speculated that, PR1, PR4 and PR8 maight participate in JA signaling pathways, while PR10 and PR17 maight participate in the SA signaling pathways4. Comparing with control plants containing empty vector, those in which PR10 was silenced appeared a high resistance to V. dahlia. Meanwhile, more lignin accumulated in the stems. Compared to the control plants, the enzymatic activity of SOD and POD showed higher activity while CAT showed lower activity, H2O2 content increased while MDA reduced in the silenced plants. Besides, silencing the PR10 could influence the expression of PR4 and PR17. Results improved that PR10 playing an important role in cotton resistence to V. dahlia.5. Furthermore, PR17 silenced plants showed a high resistance to too. And more lignin accumulatied in the stems. Compared to the control plants, both the enzymatic activity of SOD and H2O2 content were higher than the control plants; while the enzymatic activity of CAT and MDA were reduced in silenced plants. Furthermore, silencing the PR17 could influence the expression of PR1, PR4 and PR17. Results indicated that PR17 playing an important role in cotton resistence to V. dahlia.