Identification Of Disease Resistance And Physiological Parameters In StRac Transgenic Potato

Small G proteins belong to a super-family of monomeric GTP-binding proteins,which has GTPase activity.Rac is an very important family member of small G proteins.As the previous findings indicated that Rac is involved in many signal pathways,including plant defense responses,pollen tube elongation,cell differentiation,root-hair development,hydrogen peroxide accumulation and cytoskeleton recombination.In this study.StRac transgenic potato plants were used to verify whether and how StRac play a role in mediating plant physiological characteristics and broad-spectrum resistance.The results are as follows:1.We measured different physiological charateristics of potato seedlings from tissue culture.The results showed that different physiological charateristics of the line over-expressing CA-StRac was higher than control only contains empty vector p1300-GFP,the fresh weight and dry weight of different tissues(root,stem and leaf),plant height,stem diameter,leaf number,leaf area,internode length,internode number,root length and root number being increased by 64.82%,42.31%,46.67%,63.28%,35.30%,40%,8.7%,8.4%,39%,4.7%,1.9%,35.42%,35.42%and 10.61%,respectively.However,except for stem diameter,all other physiological charateristics of the line over-expressing DN-StRac transgenic plants were lower than than control only contains empty vector p1300-GFP,being decreased by64.82%?42.31%?46.67%?63.28%?35.30%?40%?8.7%?8.4%?39%?4.7%?1.9%?35.42%?35.42%?10.61%.2.We measured different physiological characteristics of potato plants from the pots as well.The results showed that the flowering time of CA-StRac transgenic plants was one day earlier than p1300-GFP ones.Compare to the line of p1300-GFP,tuber size,tuber weight,bud number and branches number of CA-StRac transgenic plants were increased by 22.12%?49.82%?2.71%?10.41%,respectively.3.We also tested broad-spectrum resistance of the transgenic lines of CA-StRac and p1300-GFP.The results showed that CA-StRac transgenic plants are more resistant against Alteraria solani,Fusarium oxysporum,Verticillium dahliae and Rhizoctonia solani,the disease symptom being decreased by 72.8%.35.6%.40%and 11.6%,respectively?...