Identification of a tomato UDP-arabinosyltransferase for airborne volatile reception

Volatiles from herbivore-infested plants function as a chemical warning of future herbivory for neighboring plants. ( Z )-3-Hexenol emitted from tomato plants infested by common cutworms is taken up by uninfested plants and converted to ( Z )-3-hexenyl β-vicianoside (HexVic). Here we show that a wild tomato species ( Solanum pennellii ) shows limited HexVic accumulation compared to a domesticated tomato species ( Solanum lycopersicum ) after ( Z )-3-hexenol exposure. Common cutworms grow better on an introgression line containing an S. pennellii chromosome 11 segment that impairs HexVic accumulation, suggesting that ( Z )-3-hexenol diglycosylation is involved in the defense of tomato against herbivory. We finally reveal that HexVic accumulation is genetically associated with a uridine diphosphate-glycosyltransferase (UGT) gene cluster that harbors UGT91R1 on chromosome 11. Biochemical and transgenic analyses of UGT91R1 show that it preferentially catalyzes ( Z )-3-hexenyl β- d -glucopyranoside arabinosylation to produce HexVic in planta .