Effects of cold stress on Abscisic acid composition by examining the gene expression and non-enzymatic antioxidants changes of Tomato (Solanum lycopersicum 'Red Cloud cultivar)

Tomato (Solanum lycopersicom L.) a main agricultural crops that is important in most countries including Iran. In this study, we investigated the SlNCED1 gene expression of biosynthetic Abscisic acid pathway by Real Time qRT-PCR and measured some of the physiological characteristics under cold stress. After fruiting, plants were placed under 2° and 4° C temperatures for 12 and 24 hours. Then, the fruits were collected for gene expression and measuring non-enzymatic antioxidant by DPPH and total phenols by Folin Ciocalteo. Results showed that the fruits at 4° C for 24 and 12 hours had more gene expression compared to other treatments. Also, non-enzymatic and total phenols had increased significantly at 2° C for 12 hours. Generally, since tomato Red Cloud cultivar belongs to tropical region, at temperatures below 12° C it is influenced by cold stress and, subsequently, it makes changes in gene expression and antioxidants to protect itself against stress.