A defensive pathway from NAC and TCP transcription factors activates a BAHD acyltransferase for (Z)-3-hexenyl acetate biosynthesis to resist herbivore in tea plant (Camellia sinensis)

Summary Numerous herbivore-induced plant volatiles (HIPVs) play important roles in plant defense. In tea plants ( Camellia sinensis ), (Z)-3-hexenyl acetate (3-HAC) has been characterized as associated with resistance to herbivores. To date, how tea plants biosynthesize and regulate 3-HAC to resist herbivores remain unclear. Based on transcriptomes assembled from Ectropis obliqua- fed leaves, a cDNA encoding BAHD acyltransferase, namely CsCHAT1 , was highly induced in leaves fed with E. obliqua . Enzymatic assays showed that CsCHAT1 converted (Z)-3-hexenol into 3-HAC. Further suppression of CsCHAT1 expression reduced the accumulation of 3-HAC and lowered the resistance of tea plants to E. obliqua , while 3-HAC replenishment rescued the reduced resistance of CsCHAT1 -silenced tea plants against E. obliqua . Two transcription factors (TFs), CsNAC30 and CsTCP11 , were co-expressed with CsCHAT1 . An integrative approach of biochemistry, DNA–protein interaction, gene silencing, and metabolic profiling revealed that the two TFs positively regulated the expression of CsCHAT1 . The suppression of either one decreased the production of 3-HAC and eliminated the resistance of tea plants to E. obliqua . Notably, the suppression of either one considerably impaired JA-induced 3-HAC biosynthesis in tea plant. The proposed pathway can be targeted for innovative agro-biotechnologies protecting tea plants from damage by E. obliqua .