A Comprehensive Analysis of Physiologic and Hormone Basis for the Difference in Room-Temperature Storability between ‘Shixia’ and ‘Luosanmu’ Longan Fruits

Abstract

Although the effects of phytohormones (mainly salicylic acid) on the storability of longan fruit have been reported, the relationship between postharvest hormone variation and signal transduction and storability remains unexplored. The basis of physiology, biochemistry, hormone content and signalling for the storability difference at room-temperature between ‘Shixia’ and ‘Luosanmu’ longan fruit were examined. ‘Luosanmu’ longan exhibited faster pericarp browning, aril breakdown and rotting during storage. ‘Luosanmu’ pericarp exhibited higher malondialdehyde but faster decreased total phenolics, flavonoid, glutathione, vitamin C, catalase activity and gene expression. Higher H2O2 and malondialdehyde but lower glutathione, glutathione-reductase and peroxidase activities, while higher activities and gene expressions of polygalacturonase, β-galactosidase and cellulose, lower covalent-soluble pectin, cellulose and hemicellulose but higher water-soluble pectin were observed in ‘Luosanmu’ aril. Lower abscisic acid and methyl jasmonate but higher expressions of LOX2, JAZ and NPR1 in pericarp, while higher abscisic acid, methyl jasmonate and salicylic acid together with higher expressions of ABF, JAZ, NPR1 and PR-1 in ‘Luosanmu’ aril were observed. In conclusion, the imbalance between the accumulation and scavenging of active oxygen in ‘Luosanmu’ longan might induce faster lipid peroxidation and senescence-related hormone signalling and further the polymerization of phenolics in pericarp and polysaccharide degradation in aril.

Changes in Polyphenolic Compounds of Hutai No. 8 Grapes during Low-Temperature Storage and Their Shelf-Life Prediction by Identifying Biomarkers

“…During the storage period of Shixia and Luosanmu longan at room temperature (25 ± 1 °C), although the content of malondialdehyde was higher, the total phenolic, flavonoid, glutathione, vitamin C, catalase and gene expression activities decreased. The results indicated that the scavenging ability of active oxygen was decreased and membrane lipid peroxidation was accelerated . A similar situation emerged with Baiyushizi pomegranates, which were stored at 25 °C for six days .…”

“…The results indicated that the scavenging ability of active oxygen was decreased and membrane lipid peroxidation was accelerated. 9 A similar situation emerged with Baiyushizi pomegranates, which were stored at 25 °C for six days. 10 Peaches exposed to 4 or 6 °C accumulated more phenolic compounds than when exposed to 0 or 2 °C.…”

Comprehensive Evaluation of the ‘Shixia’ Longan Quality under Postharvest Ambient Storage: The Volatile Compounds Played a Critical Part

“…Longan fruit ripens and is harvested in hot summer with high prevailing temperatures (25-33 • C) and humidity (>75%), which results in the extreme irresistance to postharvest long-term storage and long-distance transportation [6][7][8][9]. In general, longan fruit can be stored for about 30 days at 4-5 • C, but its shelf life is shorter (6-7 days) under ambient conditions (about 25-33 • C, >75% relative humidity) without any postharvest handlings due to its rapid peel browning, highly perishable nature, and susceptibility to postharvest pathogens such as Phomopsis longanae Chi [10] and Lasiodiplodia theobromae (Pat.)…”

“…However, the flavor quality of fruits may generally decline rapidly and undergo the processes of flavor loss as well as the production of off-flavor during the postharvest period [14]. Longan fruit, one of the typical non-climacteric fruits, is prone to rot and deteriorate in the postharvest stage manifested by pericarp browning and aril breakdown, along with the production of an unpleasant and strong off-odor, especially during storage under an ambient environment [7]. Although a series of strategies comprising physical, chemical, and biological treatments have been applied to reduce postharvest loss and extend the storage life of longan fruit over the past several decades, it cannot reverse the ultimate declining trend of quality [7,8,[15][16][17].…”

“…Longan fruit, one of the typical non-climacteric fruits, is prone to rot and deteriorate in the postharvest stage manifested by pericarp browning and aril breakdown, along with the production of an unpleasant and strong off-odor, especially during storage under an ambient environment [7]. Although a series of strategies comprising physical, chemical, and biological treatments have been applied to reduce postharvest loss and extend the storage life of longan fruit over the past several decades, it cannot reverse the ultimate declining trend of quality [7,8,[15][16][17]. Most previous studies focused on the mechanisms of the pericarp browning and aril breakdown, which are the common appearance indexes that affect the color of the longan pericarp and indicate of interior quality deterioration, respectively [9].…”