Transcriptomics and Metabolomics Reveal the Possible Mechanism by which 1-MCP Regulates the Postharvest Senescence of Zizania latifolia

To understand the mechanism governing the postharvest senescence of Zizania latifolia, and the regulatory mechanism induced by 1-methylcyclopropene (1-MCP) during storage at 25°C, physiobiochemical and conjoint analyses of the transcriptome and metabolome were performed. The results indicated that 1-MCP treatment engendered changes in the expression of genes and metabolites during the postharvest storage of Z. latifolia. The 1-MCP treatment maintained a good visual appearance, preserved the cell structure, and membrane integrity of Z. latifolia by keeping the expression of membranes-related lipolytic enzymes (and related genes) low and the amount of phosphatidylethanolamine high. Compared to the control group, 1-MCP treatment enhanced the activities of antioxidant enzymes, resulting in a decrease of reactive oxygen species (ROS) and malondialdehyde (MDA) contents, and thus inhibition of oxidative damage and loss of membrane integrity. In addition, 1-MCP treatment retarded the senescence of Z. latifolia by down-regulating the expression of ethylene biosynthesis-related genes and promoting up-regulation of brassinosteroid insensitive 1 (BRI1) kinase inhibitor 1, calmodulin (CaM), glutathione reductase, jasmonate amino acid synthase, and mitogen-activated protein kinase (MAPK)-related genes. Moreover, 1-MCP retarded Z. latifolia senescence by inducing the activity of ATP-biosynthesis related genes and metabolites. Our findings should facilitate future research on the postharvest storage of Z. latifolia, and could help delay senescence and prolong the storage time for commercial applications.

Kinetics of low-temperature catalytic combustion of ethylene at wet conditions for postharvest storage applications

The study addresses the reduction of ethylene levels in postharvest storage applications using a Pd-Zn-Sn/TiO2 catalyst, which is capable of reacting trace concentrations of ethylene at temperatures as low as 278 K and at relative humidity as high as 90%. The rate law is derived from data collected using a constant volume batch reactor and a model for a storage room with associated packed bed reactor is developed. The amount of catalyst required to maintain an ethylene concentration of 0.1 ppmv in a room containing 20 tons of fruit having an ethylene metabolism of 0.1 ul/kg hr was calculated as a function of air temperature and water content. While the catalyst is capable of continuously removing ethylene from saturated, refrigerated air, the amount of catalyst required can be reduced significantly by incorporating conventional air conditioning solutions upstream of the catalyst bed. Such combined systems and their functions are discussed

Application and toxicity studies of arabinoxylan and β-d-glucan stearic acid ester composite coatings in extending postharvest storage of peach

Peaches are good source of nutrients and known for their taste and aroma. The highly perishable nature of the peaches tends to decay rapidly during transportation and storage is a serious constraint for efficient transportation and storage. Therefore, the effect of arabinoxylan (AX) and β-D-glucan stearic acid ester (SABG) composite coating material was examined for the postharvest storage quality of peach under storage at 22 ± 2 °C with 85% relative humidity (RH). Both, AX-SABG and shellac (1–2%) coatings significantly reduced the change in the quality attributes like weight loss (1.2–1.4 fold), respiration rate (1.1–1.2 fold), ripening index (1.3–1.5 fold) and firmness (1.3–1.5 fold) during 6 days storage as compared to the uncoated peaches. In addition, AX-SABG (1–2%) coating was more effective in retaining aroma volatiles and reducing disease incidence compared to shellac. Further, acute and chronic toxicological studies have shown no tissue related toxicity and mortality in mice. Our results suggest that AX-SABG as an edible coating has the potential to preserve the fruit quality during 6 days storage at 22 ± 2 °C and extend the postharvest shelf life of peach during storage.