Phosphate deficiency enhances cotton resistance to Verticillium dahliae through activating jasmonic acid biosynthesis and phenylpropanoid pathway.

Living in natural environment, plants often suffer from various biotic and abiotic stresses. Phosphate deficiency is a common factor affecting crop production in field, while pathogen invasion is another serious problem. Here we report that Pi-deficient cotton plants exhibit enhanced resistance to Verticillium dahliae. Transcriptomic and histochemical analysis revealed that cotton phenylpropanoid pathway was activated under phosphate deficiency, including lignin and flavonoid biosynthesis. Metabolomic data showed that Pi-deficient cotton accumulates many flavonoids metabolites and displays obvious anti-fungi activity in terms of methanolic extract. Additionally, JA biosynthesis was activated under phosphate deficiency and the Pi-deficiency induced disease resistance was significantly attenuated in GhAOS knock down plants. Taken together, our study demonstrated that phosphate deficiency enhanced cotton resistance to V. dahliae through activating phenylpropanoid pathway and JA biosynthesis, providing new insights into how phosphate deficiency affects plant disease resistance.