Peach is prone to postharvest chilling injury (CI). Here it was found that exogenous ethylene alleviated CI, accompanied by an increased endogenous ethylene production. Ethylene treatment resulted in a moderately more rapid flesh softening as a result of stronger expression of genes encoding expansin and cell wall hydrolases, especially xylosidase and galactosidase. Ethylene treatment alleviated internal browning, accompanied by changes in expression of polyphenol oxidase, peroxidase and lipoxygenases. An enhanced content of phospholipids and glycerolipids and a reduced content of ceramide were observed in ethylene-treated fruit, and these were associated with up-regulation of lipid phosphate phosphatase, fatty acid alpha-hydroxylase, and golgi-localized nucleotide sugar transporter, as well as down-regulation of aminoalcohol phosphotransferases. Expression of two ethylene response factors (ERFs), ESE3 and ABR1, was highly correlated with that of genes involved in cell wall metabolism and lipid metabolism, respectively. Furthermore, the expression of these two ERFs was strongly regulated by ethylene treatment and the temperature changes during transfer of fruit into or out of cold storage. It is proposed that ERFs fulfill roles as crucial integrators between cell wall modifications and lipid metabolism involved in CI processes ameliorated by exogenous ethylene.

Although fiber-rich diets have been positively associated with sperm quality, there have not been any studies that have examined the effects of dietary fiber and its metabolites on sperm quality in young or pre-pubescent animals. In this study, we aimed to explore the effect of dietary fiber supplementation on semen quality and the underlying mechanisms in a boar model. Sixty purebred Yorkshire weaning boars were randomly divided into the four groups (T1–T4). Groups T1, T2, and T3 boars were fed diets with different levels of fiber until reaching 160 days of age and were then fed the same diet, while group T4 boars were fed a basal diet supplemented with butyrate and probiotics. Compared with T1 boars, sperm motility and effective sperm number were significantly higher among T3 boars. Meanwhile, at 240 days of age, the acetic acid and total short-chain fatty acid (SCFA) contents in the sera of T3 and T4 boars were significantly higher than those in T1 boars. The abundance of microbiota in T2 and T3 boars was significantly higher than that in T1 boars (P < 0.01). Moreover, dietary fiber supplementation increased “beneficial gut microbes” such as UCG-005, Rumenococcus, Rikenellaceae_RC9_gut_group and Lactobacillus and decreased the relative abundance of “harmful microbes” such as Clostridium_sensu_stricto_1, Romboutsia and Turicibacter. Collectively, the findings of this study indicate that dietary fiber supplementation improves gut microbiota and promotes SCFA production, thereby enhancing spermatogenesis and semen quality. Moreover, the effects of dietary fiber are superior to those of derived metabolites.