Isolation And Identification Of Cassava Aux/IAA Family As Well As Its Function In Response To Cassava Bacterial Blight

Cassava(Manihot esculenta Crantz)is an important food crop in low income tropical regions.Cassava is not only used for human and animal consumption,but also has a wide range of applications in industrial production.Cassava gets attention for the environment as a green energy alcohol raw material,and its industry scale is expanding.However,with the frequent exchange of cassava germplasm resources between China and other countries,worldwide diseases such as cassava bacterial blight have been widely spread in China,and directly affecting the development of cassava industry in China.Therefore,it is very significance to improve the disease resistance ability in cassava and excavate disease resistance genes.As the earliest plant hormone discovered,auxin plays an important role in plant growth and development,while IAA(indole-3-acetic acid)is the main form of auxin.In this experiment,we analyzed the expression profile of 37 MeIAAs members in response to Xam stress and selected 11 candidate genes of MeIAA1,MeIAA2,MeIAA4,MeIAA5,MeIAA10.MeIAA11,MeIAA17,MeIAA18,MeIAA19,MeIAA34 and MeIAA35 for further study.The specific results are as follows:1.The bioinformatics analysis showed that MelAAs and AtIAAs had higher homology,and functions in MelAAs may be similar to that in AtIAAs.All the 37 MeIAAs contained introns and exons with different lengths.2.By analyzing the expression profile of 37 MelAAs members in response to Xam stress,11 candidate genes with high relative expression levels of MeIAA1,MeIAA2,MelAA4,MeIAA5,MeIAA10,MeIAA11,MeIAA17,MeIAA18,MeIAA19,MeIAA34 and MeIAA35 were selected for further study.3.After the instantaneous transformation of 11 candidate genes into tobacco,the subcellular localization was observed,and it was found that all the 11 candidate genes were located in the nucleus.4.By transiently transforming 11 candidate genes into tobacco,the number of bacteria after Xam inoculation was found that the number of bacteria in candidate genes was less than that in the control group.5.Gene silencing of MeIAA1/2,MeIAA4/5,MeIAA10/11,MeIAA18/19 and MeIAA34/35 through VIGS found that the number of bacteria were higher than that in the control group after Xam inoculation.The number of deposited corpus callosum in the same period after gene silence was lower than that in the control group.MePRs gene expression level suggested that MePRs expressed lower in the experimental group than that in control group.