The 4-phosphopantetheinyl transferase of Trichoderma virens plays a role in plant protection against Botrytis cinerea through volatile organic compound emission.

Aims: This work was conducted to examine the effects of volatile organic compounds (VOCs) from Trichoderma virens and the 4-phosphopantetheinyl transferase 1 (TvPPT1) mutant in growth promotion and induction of defense responses of Arabidopsis thaliana seedlings using a co-cultivation system in vitro . Methods: The contribution of VOCs to plant development and immunity was assessed by comparing the effectiveness of WT and Δ ppt1 mutant strains of T. virens in the formation of lateral roots and protection conferred against Botrytis cinerea. VOCs released by T. virens and Δ ppt1 mutant were compared by gas chromatography-mass spectrometry. Results: Plants exposed to volatiles from WT T. virens showed 2-fold increase in fresh weight when compared to axenically-grown seedlings, which correlated with increased root branching and enhanced expression of the jasmonic acid-responsive marker pLox2:uidA as well as accumulation of jasmonic acid and hydrogen peroxide. T. virens produced a series of hydrocarbon terpenes, including the sesquiterpenes β-caryophyllene, (−)-β-elemene, germacrene D, τ-cadinene, δ-cadinene, α-amorphene, and τ-selinene and the monoterpenes β-myrcene, trans-β-ocimene, and cis-β-ocimene that were absent in TvPPT1 mutant. Conclusions: Our results indicate that T. virens VOCs elicit both development and defense programs and that PPT1 plays an important role in biosynthesis of terpenes and plant protection against B. cinerea. [ABSTRACT FROM AUTHOR]