Association of volatile terpenoids and their biosynthetic genes in hightemperature stress tolerance in tomato (Solanum lycopersicum L.)

One of the major limiting factors for the production of tomato is the high temperature stress. Plants are capable of sensing the stress early and produce the terpenoid compounds which may contribute for tolerance or act as a signaling compound to trigger the expression of many tolerant genes. Therefore, the present study was conducted to understand the variability in the production of volatile terpenoid compounds in tolerant (IIHR-2841) and susceptible (IIHR-2914) genotypes and the related gene expression under high temperature stress conditions. Genotypes IIHR-2841 and IIHR-2914 were exposed to high temperature (40±2°C) at early flowering stage using polytunnel. Volatile compounds were extracted and identified using SPME-GC-MS. Higher expression of the terpenoid synthase genes and increased release of terpenoids were observed in the tolerant genotype under stress. Expression of β-Caryophyllene synthase (TPS12) and β-Phyllandrene synthase (TPS20) showed a remarkable 2-fold increase at 9th day of temperature stress in tolerant genotype IIHR-2841 whereas; IIHR-2914 did not show upregulation.