Project description:Wax apple is one of the most popular tropical fruit but undergoes serious post-harvest decay during storage, transportation and marketing. Melatonin (MT) plays important roles in plant growth, development and stress responses. However, its function in post-harvest preservation of fruit remains largely unknown. In the present study, the physiological function and molecular mechanism of exogenous MT for post-harvest preservation were evaluated in wax apple fruit. Results showed that MT treatment remarkably reduced decay incidence and the accumulation of excess reactive oxygen species (ROS) but increased the activity of antioxidant enzymes, suggesting that exogenous MT alleviates the post-harvest decay of wax apple by regulating the balance between ROS production and antioxidant system. Meanwhile, the gene expression was analyzed by transcriptome confirmed by quantitative PCR. This study provides insights into the regulatory mechanism and proper application strategies for post-harvest preservation of wax apple and other fruits though melatonin manipulation.
Project description:Our experiments show that exogenous MT treatment can effectively delay the decay and water loss rate of post-harvest wax apples, which may be related to reducing the degree of membrane lipid peroxidation and inhibiting enzymatic browning. MT treatment also maintains the quality of post-harvest wax apple by enhancing the activity of antioxidant enzymes. At the same time, it can reduce the incidence of post-harvest diseases of wax apple by increasing the JA and SA contents. MT can down-regulate the expression of genes related to oxidation, and up-regulate the expression of related genes in antioxidant enzymes and non-enzymatic antioxidant pathways, suggesting that exogenous melatonin can reduce the production of excess ROS and maintain the redox homeostasis of post-harvest wax apple. Therefore, melatonin, as a strong and effective free radical scavenger and antioxidant, plays an important role in delaying the decay of post-harvest wax apples and prolonging the shelf life.
Project description:The effect of four commercial Saccharomyces cerevisiae strains (D254, VIC, BV818, and RV100) on the volatile profile of wax apple (Syzygium samarangense) wine was investigated in this study. Alcohols and esters were the most two abundant groups of identified volatiles in wax apple wines. However, different S. cerevisiae strains possess various capacities in releasing/synthesizing volatiles with varied mRNA levels of genes involved in volatiles metabolism during wax apple wine fermentation. VIC, which yielded the highest total concentration of volatiles and largest number of volatiles with odor activity value (OAV) > 1, could be used as a starter culture to produce wax apple wine characterized with intense aroma. D254 and RV100, which produced the greatest variety of volatiles and scored the highest in global aroma, respectively, could be used to enhance the wine complexity. Four wax apple wines could be differentiated by their main volatile compounds.