Metabolic change of oxylipin pathway in cold responses of chickpea plants

Abstract

Oxylipins the products of fatty acid oxidation, to acclimate biotic and abiotic stresses. In this study, we evaluate the effects of cold stress by measuring manlodialdehyde (as membrane damage index), the activity of lipoxygenase (LOX) and allene oxide synthase (AOS) enzymes, the levels of transcript LOX, AOS and allene oxide cyclase (AOC) genes using quantitative reverse-transcriptase polymerase chain reaction (qPCR) under cold stress (4°C) in tolerant (Sel96Th11439) and susceptible (ILC533) chickpea (Cicer arietinum L.) genotypes. The data analysis revealed that under cold stress, MDA content significantly increased in both genotypes so that MDA content in susceptible plants was maximum on day 6 of cold stress ( by 57%) whereas in tolerant genotype, after an increase on day 1 of cold stress its content did not significantly change. Such increase in MDA content showed signaling role and induction of defense mechanisms in tolerant genotype. Under cold stress, the activity of LOX and AOS significantly increased in susceptible genotype compared to tolerant one. Therefore, the activity of AOS pathway, as main pathway of oxylipin was considered in chickpea under cold stress, indicating probably its role in creating jasmonates and induction of defense genes. The analysis of transcription level of LOX, AOS and AOC genes with REST software confirmed changes in oxylipin components. Thus degree of cold tolerance in tolerant plants was related with cell damages content and the activity of oxylipin pathway under cold stress.

Keywords

• gene expression
• cold stress
• oxylipin
• allene oxide synthase