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

我们调查是否磷脂酶发挥柑橘类水果易患由感染作用青霉，以及是否在柑橘类水果-之间的激素脱落酸（ABA）和磷脂酶存在连接状青霉互动。脐橙（柑橘）感染中PLD，PLC和PLA ₂酶活性以及编码它们的一组基因的表达变化比较了（L.）Osbeck）橙及其抗感染性较低的ABA缺失突变体Pinalate。结果表明，病害发生前受感染的脐橙果实中PLD和PLC的激活，并且这种激活在突变体中被减弱，这表明这两种酶在柑橘类水果中均具有保护作用，以应对指点疟原虫感染和ABA的参与。在他们的监管中。转录分析进一步证明了真菌对各种磷脂酶编码基因的差异激活。在CsPLD基因（CsPLDα，CsPLDβ，CsPLDδ，CsPLDγ，CsPLDζ）中，真菌对CsPLDγ和CsPLDζ具有更强的作用。这是第一个表明PLDζ同工型参与植物-微生物相互作用的报道，并表明该基因可能被ABA响应感染而调节。结果还表明，编码非特异性PLC（NPC）和磷酸肌醇特异性PLC（PI-PLC）的CsPLC亚型可能参与了柑橘类水果-数指疟原虫的相互作用，并且ABA作用发生在CsPI-PLC基因的上游在被感染的柑橘类水果中激活。真菌诱导的PLA ₂活性和基因表达的变化相关性较小。