Knockdown of Sly-miR164a Enhanced Plant Salt Tolerance and Improved Preharvest and Postharvest Fruit Nutrition of Tomato.

Salinity stress is a serious limitation to tomato growth and development. The aim of this study was to investigate the effects of Sly-miR164a on tomato growth and fruit nutritional quality under salt stress. The results showed that the root length, fresh weight, plant height, stem diameter and ABA content of miR164a#STTM (knockdown of Sly-miR164a) lines were higher than those of WT and miR164a#OE (overexpression of Sly-miR164a) lines under salt stress. Compared with WT, miR164a#STTM tomato lines exhibited lower ROS accumulation under salt stress. In addition, the fruits of miR164a#STTM tomato lines had higher soluble solids, lycopene, ascorbic acid (ASA) and carotenoid content compared with WT. The study indicated that tomato plants were more sensitive to salt when Sly-miR164a was overexpressed, while knockdown of Sly-miR164a enhanced plant salt tolerance and improved fruit nutritional value.

The effect of BVOCs produced by Lysinibacillus fusiformis and LED irradiation on pigment metabolism in stored broccoli.

Volatile organic compounds produced by bacteria (BVOCs) have been proven to effect the postharvest metabolism of fruits and vegetables. The quality, color and antioxidant capacity of membrane lipids of broccoli in storage were effectively maintained by fumigation with BVOCs produced by Lysinibacillus fusiformis combined with white light emitting diode (LED) technology. An analysis of the transcriptome and metabolome of broccoli treated with the combined LED-BVOCs technology resulted in the identification of 49 differentially expressed genes (DEGs) and 13 differentially abundant metabolites (DAMs) involved in photosynthesis (32/0 DEGs upregulated/downregulated; 0/0 DAMs with increased/decreased abundance), chlorophyll (7/0; 1/2), carotenoid (5/0; 1/4) and flavonoid (3/3; 3/2) metabolism. The maintenance of green color in harvested broccoli treated by LED-BVOCs was associated with DEGs and DAMs that inhibited chlorophyll degradation and carotenoid accumulation. Our study provides a theoretical basis for understanding the delayed senescence of broccoli during storage using BVOCs-LED technology.

Silencing of Sly-miR171d increased the expression of GRAS24 and enhanced postharvest chilling tolerance of tomato fruit.

The role of Sly-miR171d on tomato fruit chilling injury (CI) was investigated. The results showed that silencing the endogenous Sly-miR171d effectively delayed the increase of CI and electrolyte leakage (EL) in tomato fruit, and maintained fruit firmness and quality. After low temperature storage, the expression of target gene GRAS24 increased in STTM-miR171d tomato fruit, the level of GA3 anabolism and the expression of CBF1, an important regulator of cold resistance, both increased in STTM-miR171d tomato fruit, indicated that silencing the Sly-miR171d can improve the resistance ability of postharvest tomato fruit to chilling tolerance.