Identification Of The Interaction Between ZmCCaMK And ZmWRKY62 And Functional Analysis Of The ZmWRK62

Absicic acid(ABA)as a vital phytohormone,plays an essential role in the growth and development of the plants.Moreover,ABA regulates the adaptive plant responses to various stresses via inducing the antioxidant defense system.Many signaling molecules,such as H2O2,calcium ion(Ca2+)and nitric oxide(NO),and protein kinases,such as mitogen-activated protein kinase(MAPK)and calcium/calmodulin-dependent protein kinase(CCaMK)have been found to involve in this process.However,the mechanism of ZmCCaMK in ABA-induced antioxidant defense remains unclear.Using the two yeast-hybrid system,we screened a transcription factor-ZmWRKY62 which could interact with ZmCCaMK in yeast.In this chapter,the authenticity of their interaction was further confirmed and the function of ZmWRKY62 in ABA-induced antioxidant system was investigated.The results as follows:1.ZmWRKY62 was confirmed to interact with ZmCCaMK in vivo and in vitro using the GST-pull down assay,BiFC test and Co-IP analysis;2.Exogenous ABA significantly increased the texpression of ZmWRKY62 in 90 min and the expression of ZmCCaMK in 30 min;3.Transient expressing the ZmWRKY62 in maize protoplasts showed that overexpress the ZmWRKY62 resulted in significant increases in the activities of APX and SOD when comparedwith the control,which were further enhanced by ABA treatment;Conversely,transient silencing of ZmWRKY62 decreased the activities of APX and SOD,which could not be restored to the level of controls by ABA treatment,these results showed that ZmWRKY62 is involved in the ABA-induced antioxidant defense system;4.Transient expressing or transient silencing the ZmWRKY62 in maize protoplasts,the results showed that overexpress the ZmWRKY62 resulted in significant increases the fluorescences intensityin when comparedwith the control,which were further enhanced by ABA treatment;Conversely,transient silencing of ZmWRKY62 decreased the fluorescences intensity when compared with the control,which could not be restored to the level of controls by ABA treatment,Experiments show ZmWRKY62 pathway involved in H2O2-induced ABA;From the above results showed that ZmWRKY62 was confirmed to interact with ZmCCaMK in vivo and in vitro,ZmWRKY62 and ZmCCaMK are involved in ABA-induced antioxidant defense,but the relationship between the two has to be further studied.