Functional Analyses Of Wheat Copine Genes TaBON1 And TaBON3 In Disease Resistanse Against Powdery Mildew

Powdery mildew,caused by the biotrophic fungal pathogen Blumeria graminis f.sp.Tritici(Bgt),is a major threat for the production of wheat(Triticum aestivum L.).It is of great importance to identify new resistance genes for generating Bgt resistant or tolerant wheat varieties.Here,we show that wheat copine genes TaBON1 and TaBON3 negatively regulate wheat disease resistance to Bgt.Two copies of TaBONl and three copies of TaBON3 located on chromosomes 6AS,6BL,1AL,1BL and 1DL,respectively,were identified from the current common wheat genome sequences.The expression of TaBON1 and TaBON3 are in different tissues,including including root,stem,young leaf,senescent leaf and spike,among which the expression was highest in the young leaf and the lowest in the root.The expression of TaBONl and TaBON3 are responsive to both pathogen infection and temperature changes.Knocking down of TaBON1 or TaBON3 by virus induced gene silencing(VIGS)each induces upregulation of defense responses in wheat.These TaBON1 or TaBON3 silenced plants exhibit enhanced wheat disease resistance to Bgt accompanied by higher accumulation of hydrogen peroxide and heightened cell death.In addition,high temperature has little effect on the upregulation of defense response genes and ROS marker genes conferred by silencing TaBON1 or TaBON3,which is different from the high temperature inhibition of defense upregulation in the Arabidopsis BON1 knockout mutant.Our study shows a conserved function of the plant copine genes in plant immunity and provides new genetic resources for improving resistance to powdery mildew in wheat.