Interrelation between ABA and phospholipases D, C and A2 in early responses of citrus fruit to Penicillium digitatum infection

Abstract We investigated whether phospholipases play a role in citrus fruit susceptibility to be infected by Penicillium digitatum, and connection exists between hormone abscisic acid (ABA) the fruit-P. digitatum interaction. Changes both activity of enzymes PLD, PLC PLA2 expression set genes encoding them response infection Navelate (Citrus sinensis (L.) Osbeck) orange its ABA-deficient mutant Pinalate, which is less resistant infection, were compared. The results showed activation PLD before disease development, this was attenuated mutant, suggests that protective cope with P. participation ABA their regulation. transcriptional analyses further demonstrated differential various phospholipases-encoding fungus. Of CsPLD (CsPLDα, CsPLDβ, CsPLDδ, CsPLDγ, CsPLDζ), fungus had stronger effect on CsPLDγ CsPLDζ. This first report suggest PLDζ isoform plant-microbe interaction, indicate gene may modulated infection. also revealed CsPLC isoforms non-specific (NPC) phosphoinositide-specific PLCs (PI-PLC) participate action occurs upstream CsPI-PLC fruit. changes induced relevant.