Functional Characterization Of A CBL-Interacting Protein Kinase Gene (TaCIPK16) Reveals Its Involvement In Wheat Resistance Against Puccinia Striiformis F.sp.tritici

Calcium plays a pivotal role in regulating the physiological as well as developmental processes in plants.One of the major calcium sensors is calcineurin B-like(CBL).Calciummediated signal is transduced downstream by CBL-interacting protein kinases(CIPKs).Wheat CBL-interacting protein kinase(TaCIPK16)is a novel plant-specific family of serinethreonine kinase that CBLs specifically target.Wheat is subjected to biotic and abiotic stresses and CBL-CIPK complexes may play a critical role under these stresses.In this study,we reported that functional characterization of a CBL-interacting protein kinase gene(TaCIPK16)reveals its involvement in wheat resistance against Puccinia striiformis f.sp.tritici(Pst).The transcript levels of TaCIPK16 were up-regulated in response to an avirulent Pst race CYR23 of Pst whereas transcript levels were almost steady to the virulent raceCYR31.The expression of TaCIPK16 was increased when treated with abscisic acid(ABA)and salicylic acid(SA)and exposed to abiotic stresses,especially cold and dry treatments,suggesting TaCIPK16 is involved in the ABA and SA signaling pathways.TaCIPK16-GFP fusion protein is localized throughout the cell,especially in the nucleus and plasma membrane.Yeast two-hybrid assay showed that TaCIPK16 strongly interacts with TaCBL4 and TaCBL9.After knocking down TaCIPK16 gene by barley stripe mosaic virus(BSMV)-based virus induced gene silencing(VIGS)system,the growth of Pst hyphae,number of hyphal branches and haustorial mother cells were increased.Our findings suggest that TaCIPK16 contributes to wheat disease resistance against Pst.