Methyl jasmonate treatment alleviates chilling injury and improves antioxidant system of okra pod during cold storage

Abstract

Okra pod is sensitive to low temperature, which results in chilling injury under improper low‐temperature storage. This study aimed to evaluate the effect of different concentrations of methyl jasmonate (MeJA) treatment on okra pod stored at 4 ± 1°C for 12 days and illuminate the mechanism of MeJA alleviating chilling injury. Compared to the control, MeJA treatments maintained lower relative electric conductivity (REC), chilling injury (CI) degree, and lignin content, as well as higher total soluble solids, total soluble sugar, pectin content, and chlorophyll content. The factor analysis was applied to comprehensively evaluate the effects of MeJA so that 1 μmol/L MeJA was screened as the optimum concentration to maintain the okra quality throughout the storage time. In contrast with control, MeJA not only accelerated the generation of antioxidant substances (phenolics and flavonoids) but also increased the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) activity, inhibited malondialdehyde (MDA), hydrogen peroxide (H2O2) content accumulation, and the polyphenol oxidase (PPO) activity. This work confirmed that MeJA could effectively alleviate chilling injury and maintain the quality during cold‐stored by regulating reactive oxygen species (ROS) metabolism. These results provide theoretical guidance for the application of MeJA in okra storage and preservation.

IbNIEL‐mediated degradation of IbNAC087 regulates jasmonic acid‐dependent salt and drought tolerance in sweet potato

“…JA was much more abundant in IbNAC087 ‐OE plants but significantly less abundant in IbNAC087 ‐Ri lines under normal, salt, and drought conditions than in WT plants (Figure 3D; Table S4). Because JA is a crucial regulator in activating antioxidant enzymes to promote reactive oxygen species (ROS) scavenging mechanisms under abiotic stress in plants (Ma et al, 2021; Liu et al, 2023), several related physiological indices were measured. Compared with WT plants, IbNAC087 ‐OE lines had higher SOD, CAT, and peroxidase (POD) activities and accumulated less MDA and H 2 O 2 under salt and drought stresses, whereas the opposite patterns were observed in IbNAC087 ‐Ri plants (Figure 3E–I; Table S4).…”

“…JA was much more abundant in IbNAC087-OE plants but significantly less abundant in IbNAC087-Ri lines under normal, salt, and drought conditions than in WT plants (Figure 3D; Table S4). Because JA is a crucial regulator in activating antioxidant enzymes to promote reactive oxygen species (ROS) scavenging mechanisms under abiotic stress in plants (Ma et al, 2021;Liu et al, 2023), several related physiological indices were measured.…”