Abstract
Methyl jasmonate (MJ) is an important plant growth regulator that plays a key role in tolerance to biotic and abiotic stresses. In this research, the effects of exogenous MJ on cold tolerance, photosynthesis, activity and gene expression of antioxidant enzymes, proline accumulation, and expression of cold-regulated (COR) genes in wheat seedlings under low temperature (4 °C) were investigated. Exogenous MJ treatment (1 µM) promoted wheat cold tolerance before and during cold exposure. Low temperature significantly decreased photosynthetic parameters, whereas MJ application led to their partial recovery under cold exposure. Hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels increased in response to low temperature, and this was counteracted by MJ application. Exogenous MJ significantly enhanced the activities of antioxidant enzymes and upregulated the expression of MnSOD and CAT during cold exposure. MJ application also led to enhanced proline content before 4 °C exposure, whereas the P5CS gene expression was upregulated by MJ’s presence at both normal (22 °C) and low (4 °C) temperatures. It was also shown that MJ tended to upregulate the expression of the COR genes WCS19 and WCS120 genes. We conclude that exogenous MJ can alleviate the negative effect of cold stress thus increasing wheat cold tolerance.
Highlights
Low temperature is a major environmental stress that limits distribution, growth, development, and yield of crop plants
Our results indicated that application of methyl jasmonate (MJ) at low concentration (1 μM) upon prolonged incubation (7 day) further reduced the water loss in leaves of wheat seedlings exposed to low temperature
The results show that cold-induced expression levels of WCS19 and WCS120 genes were significantly upregulated by MJ before cold exposure
Summary
Low temperature is a major environmental stress that limits distribution, growth, development, and yield of crop plants. They are lipid-derived oxylipins produced as a result of lipoxygenases-mediated oxygenation of polyunsaturated fatty acids [3,4] These crucial plant hormones are known to modulate morphological, physiological, and biochemical processes in plants, playing important roles in regulation of plant growth and development, flowering, trichome initiation, and leaf senescence [2,5,6]. They mediate defense responses against herbivores, necrotrophic pathogens, and nematodes as well as mutualistic symbiotic microorganisms [3,7]. They regulate adaptation of plants to abiotic stresses in-
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
