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Fengtang plum is popular with consumers because of its unique taste and high nutritional value. In this paper, three different harvest maturity Fengtang plums were used as experimental materials. After treated with 0.5 μL/L and 1.0 μL/L 1-methylcyclopropene (1-MCP), the fruits was stored at (25 ± 2)°C for 14 days. The decay rate, respiratory intensity, ethylene release rate, firmness, color, soluble solid content, titratable acid content, and solid-acid ratio were measured every 2 days, and sensory evaluation was made. In addition, the effects of 1-MCP on the shelf quality and volatile substances of different maturity plums were analyzed by GC-MS. Results showed that the Fengtang plum was a typical non-climacteric fruit. Harvest maturity was the main reason affecting the quality change of Fengtang plums during their shelf life. The higher the harvest maturity, the higher the decay rate of plum fruit during shelf life, the more vigorous the respiration, the more rapid the quality deterioration. A high concentration of 1-MCP (1.0 μL/L) treatment could delay the quality deterioration of different maturity plum fruit during shelf life, and the effect of high maturity (110 days after flowering) fruit preservation was the most obvious. GC-MS analysis showed that aldehydes (grassy aroma) and esters (fruit aroma) were the main volatile substances in Fengtang plums, and the higher the harvest maturity, the lower the aldehyde content and the higher the ester content. Different concentrations of 1-MCP treatment could delay the decrease of aldehyde content and the increase of ester content during the shelf life of plum fruit, and more effectively maintain the inherent aroma of plum fruit. Combined with the results of the solid-acid ratio and sensory evaluation, the high-maturity plum fruit had the best flavor during shelf life. 1-MCP treatment (1.0 μL/L) could effectively delay the quality deterioration and flavor loss of different maturity plum fruit during shelf life and had the best shelf preservation effect on high-maturity plum fruit. [ABSTRACT FROM AUTHOR]

The miRNA167 (miR167a) family is a conserved type of microRNA in plants, which mainly regulates the Auxin Response Factors (ARF) family genes to influence the auxin signaling pathway and control fruit ripening. In the present study, the overexpression of miR167a (OE- miR167a) and Silencing- miR167a by short tandem target mimic (STTM- miR167a) tomato lines was obtained by Agrobacterium-mediated transformation. The results showed that the STTM- miR167a reduced the accumulation of lycopene, carotenoid and delayed preharvest ripening of tomato fruit. Additionally, STTM- miR167a lines up-regulated SlIAA genes by increasing the expression level of SlARF6 and SlARF8 to generate similar phenotypic changes to reduction in auxin response. This study expanded the cognition of function of miR167a-ARF6/8 module in the preharvest ripening and postharvest senescence of tomato fruit. • STTM- miR167a delayed preharvest ripening of tomato fruit. • OE- miR167a accelerated the preharvest ripening of tomato fruit. • The accumulation of lycopene and carotenoid were reduced in STTM- miR167a fruit. • STTM- miR167a up-regulated SlIAAs genes by increasing the expression of SlARF6 /8. [ABSTRACT FROM AUTHOR]

• Combined 1-MCP and sterilizing medium is an effective preservation technology. • 1-MCP + O 3 treatment effectively delayed the softening and senescence of fruit. • 1-MCP + O 3 treatment could induce resistance of fruit at earlier shelf storage. • 1-MCP + O 3 could maintain brighter color attributes of peaches during shelf life. • At the end of storage, 1-MCP + O 3 maintained the best integrity of flesh tissue. Physiological senescence and quality deterioration of peach after harvest were the restrict factors of peach shelf quality. As an ethylene inhibitor, 1-Methylcyclopropene (1-MCP) can effectively dealy fruit ripening and senescence, and improve storage quality. However, studies showed that the effect of fruit preservation by only using 1-MCP is unsatisfactory. Therefore, in this study, 1-MCP combined with sterilizing medium including ozone, TiO 2 photocatalytic and epsilon-polylysine (ε-PL) was applied for enhancement of preservative ability with safety and pollution-free. The flow microcirculation was used for enhancing the effect of sterilizing medium. Results showed that all these three treatment methods can enhance the shelf quality of peach fruit. Among them, the combination treatment of 1-MCP and ozone played a more active role in inhibiting decay, respiration, ethylene production, decline of nutrients such as organic acids and soluble solids. Moreover, it maintained bright color value and cell integrity of peach fruit. In addition, the combined treatment of 1-MCP and ozone had significant effects on inducing resistance in fruit and slowing down membrane lipid peroxidation. In conclusion, 1-MCP combined with ozone was an effective method to delay the senescence and improve the storage shelf quality of fruit, which is beneficial to the guidance of production practice and has potential application prospects in fruit preservation. [ABSTRACT FROM AUTHOR]

The miR160 is a highly conserved microRNA (miRNA) that regulates the auxin signaling pathway through negative regulation of auxin response factors (ARFs) and plays pivotal roles in fruit development. In the present study, the knockdown of miR160a using short tandem target mimic (STTM 160a) and overexpression of miR160a (miR160a-OE) transgenic tomato lines were generated to investigate the possible roles of miR160 in postharvest ripening tomato fruit. The results showed that the STTM 160a increased total chlorophyll content, reduced lycopene and total carotenoid accumulation, weight loss, and respiration rate while increasing firmness in tomato fruit compared with the wild-type (WT) and miR160a-OE. Additionally, miR160a-OE lines exhibited a typical auxin hypersensitivity and postharvest ripening acceleration, whereas STTM 160a lines displayed an auxin hyposensitivity and postharvest ripening reduction. Moreover, the relative expression levels of ARF10A (Solyc11g069500.2.1), ARF10B (Solyc06g075150.3.1), ARF17 (Solyc11g013480.2.1), and Aux/IAA genes were up-regulated in STTM 160a lines. The results suggest that the knockdown of Sly-miR160a delays postharvest ripening in tomato fruit, and provide valuable information for genetic engineering in controlling developmental processes. • Knockdown of miR160a delayed postharvest ripening of tomato fruit. • Overexpression of miR160a improved chlorophyll degradation, and enhanced lycopene content. • Knockdown of miR160 reduced auxin content and prolonged shelf life. • ARF10A/10B/17 targeted by miR160a are involved in regulating postharvest ripening of fruit. [ABSTRACT FROM AUTHOR]

Fruit ripening of tomato is regulated by NAC (NAM, ATAF1/2, and CUC2) domain proteins such as NOR-like1, SlNAC1, and SlNAC4. Acts as an up-stream regulator of NAC genes, the high abundance of miR164 might eliminate the impact of NAC on the ripening of fleshy fruit. In the present study, the STTM-miR164a (silencing miR164a by short tandem target mimic) and OE-miR164a (overexpression of miR164a) tomato lines were generated. Compared with those of silenced miR164a , overexpression of miR164a decreased ethylene production and lycopene accumulation, and delayed pre-and postharvest ripening of fruit. The expression analysis of target genes of miR164a revealed that the NAM3 (Solyc06g069710), GOB (Solyc07g062840) and NAC1 (Solyc07g066330) were involved in regulating fruit ripening. • Overexpression of miR164a decreased ethylene production and lycopene accumulation. • Silence of miR164a promoted chlorophyll loss and increased lycopene accumulation. • NAC was involved in miR164a regulating fruit preharvest and postharvest ripening. • Silence of miR164a accelerated fruit preharvest and postharvest ripening. • Overexpression of miR164a delayed fruit preharvest and postharvest ripening. [ABSTRACT FROM AUTHOR]

• Melatonin significantly promoted ripening of postharvest tomato fruit. • Melatonin changed the DNA methylation level of ethylene signaling genes. • Melatonin treatment induced the expression level of ethylene signaling genes. • The dynamic changes of DNA methylation were involved in fruit ripening. Melatonin (MT) as an evolutionarily highly conserved molecule plays an exceptional role in plants. In the present study, the regulation mechanism of the DNA methylation of CpG islands of ethylene signaling genes induced by MT on postharvest ripening of tomato fruit was studied. The ripening of tomato fruit was significantly promoted by the 0.5 mM MT treatment, as revealed by the appearance color, the lycopene, total soluble solids and vitamin C content of the fruit. In the MT treated fruit, the DNA methylation levels of CpG island of S lACS10 and SlERF-A1 were decreased, and the DNA methylation level of CpG island of SlCTR1 was increased. In addition, MT treatment increased the expression level of SlACS10, SlEIN3, SlERF-A1 and SlERT10 , inhibited the expression level of SlCTR1 , and by which the ethylene signaling might be activated and the ripening was promoted. The effect of MT on the DNA methylation of CpG islands of genes involved in ethylene signaling may contribute to the ripening of tomato fruit. The present study provided valuable information for understanding the essential role of DNA methylation in the postharvest ripening of tomato fruit. [Display omitted] [ABSTRACT FROM AUTHOR]