Impact of temperature variation on the phytotoxic secondary metabolite production by Lasiodiplodia theobromae

Botryosphaeriaceae species are associated with grapevine trunk diseases. Lasiodiplodia theobromae plays a significant role as one of the most virulent grapevine pathogens in the world. In this study, we evaluate the effects of temperature on phytotoxin-induced virulence in Lasiodiplodia theobromae. The fungal strain is grown in Czapek-Dox liquid medium at four different temperatures (20 degrees C, 25 degrees C, 30 degrees C and 35 degrees C) for 14 days under dark conditions. The culture filtrates were screened for three selected phytotoxins, indole-3-carboxylic acid, jasmonic acid, and lasiodiplodin using UPLC MS/MS techniques. Phytotoxicity of the crude culture filtrates was tested on detached grapevine leaves. With UPLC MS/MS analysis, we identified that indole-3-carboxylic acid and jasmonic acid production varied with the increasing temperature, and did not detect any lasiodiplodin. At high temperatures, we observed a significant increase in the phytotoxicity of crude culture filtrates on the detached grapevine leaves. The most severe necrotic leaf lesions were observed when inoculated with crude culture filtrates extracted at 35 degrees C.

Automated summary

This study evaluated the impact of temperature on phytotoxin-induced virulence in Lasiodiplodia theobromae, revealing that the production of plant toxins increased at higher temperatures, resulting in significantly higher toxicity to grapevine leaves.