Cloning And Functional Analysis Of Auxin Response Genes IbIAA13 And IbIAA22 In Sweetpotato

As an important food crop and a new energy crop,sweetpotato has strong adaptability and high yield.However,the development of sweetpotato industry is limited by many adverse factors such as biological stresses and abiotic stresses.Aux/IAA genes family is a member of the early auxin response gene family,which is involved in auxin regulation of many stages of plant development.At present,Aux/IAA genes have been isolated from a variety of plants and their functions have been identified,but the functions of Aux/IAA genes family members in sweetpotato have not been reported.In this study,IbIAA13 and IbIAA22 genes were cloned from Jishu25,and overexpressing sweetpotato plants were obtained by Agrobacterium tumefaciens mediated method.The functions of IbIAA13 and IbIAA22 genes were preliminatively identified.(1)The total length of IbIAA13 gene is 915 bp,encoding 304 amino acids.The relative molecular weight of encoded protein is 32.3 k Da,and the isoelectric point is 6.46.The encoded protein is a hydrophilic protein,which is localized in the nucleus.The q RT-PCR analysis showed that IbIAA13 gene was up-regulated by IAA,ABA,GA3,salt stress and drought stress in Jishu25.The overexpression vector p CAMBIA-1301-IbIAA13 was constructed and overexpressing sweetpotato plants were obtained.The result showed that overexpressed sweetpotato was less sensitive to IAA and more resistant to drought and salt stresses compared with WT.(2)The total length of IbIAA22 gene is 582 bp,encoding 193 amino acids.The relative molecular weight of encoded proteinis 21.7 k Da,and the isoelectric point is 8.24.The encoded protein is a hydrophilic protein,which is located in the nucleus.The q RT-PCR analysis showed that IbIAA22 gene was up-regulated by IAA,ABA,salt stress and drought stress,and down-regulated by GA3.The overexpression vector p CAMBIA-1301-IbIAA22 was constructed and overexpressing sweetpotato plants were obtained.