Contents Summary1724I.Introduction1725II.Ripening genes1725III.The importance of ethylene in controlling ripening1727IV.The importance of MADS‐RIN in controlling ripening1729V.Interactions between components of the ripening regulatory network1734VI.Conclusions1736Acknowledgements1738Author contributions1738References1738 Summary Understanding the regulation of fleshy fruit ripening is biologically important and provides insights and opportunities for controlling fruit quality, enhancing nutritional value for animals and humans, and improving storage and waste reduction. The ripening regulatory network involves master and downstream transcription factors (TFs) and hormones. Tomato is a model for ripening regulation, which requires ethylene and master TFs including NAC‐NOR and the MADS‐box protein MADS‐RIN. Recent functional characterization showed that the classical RIN‐MC gene fusion, previously believed to be a loss‐of‐function mutation, is an active TF with repressor activity. This, and other evidence, has highlighted the possibility that MADS‐RIN itself is not important for ripening initiation but is required for full ripening. In this review, we discuss the diversity of components in the control network, their targets, and how they interact to control initiation and progression of ripening. Both hormones and individual TFs affect the status and activity of other network participants, which changes overall network signaling and ripening outcomes. MADS‐RIN, NAC‐NOR and ethylene play critical roles but there are still unanswered questions about these and other TFs. Further attention should be paid to relationships between ethylene, MADS‐RIN and NACs in ripening control.

This article focuses on the molecular and hormonal mechanisms underlying the control of fleshy fruit ripening and quality. Recent research on tomato shows that ethylene, acting through transcription factors, is responsible for the initiation of tomato ripening. Several other hormones, including abscisic acid (ABA), jasmonic acid (JA) and brassinosteroids (BR), promote ripening by upregulating ethylene biosynthesis genes in different fruits. Changes to histone marks and DNA methylation are associated with the activation of ripening genes and are necessary for ripening initiation. Light, detected by different photoreceptors and operating through ELONGATED HYPOCOTYL 5(HY5), also modulates ripening. Re-evaluation of the roles of ‘master regulators’ indicates that MADS-RIN, NAC-NOR, Nor-like1 and other MADS and NAC genes, together with ethylene, promote the full expression of genes required for further ethylene synthesis and change in colour, flavour, texture and progression of ripening. Several different types of non-coding RNAs are involved in regulating expression of ripening genes, but further clarification of their diverse mechanisms of action is required. We discuss a model that integrates the main hormonal and genetic regulatory interactions governing the ripening of tomato fruit and consider variations in ripening regulatory circuits that operate in other fruits.

A high-fat diet (HFD) has been a major contributor to increasing morbidity caused by metabolic syndromes. Functional foods from natural sources are potential choices for addressing metabolic diseases because they provide many health benefits with a low level of adverse side effects. In our former reports, fucoidan from Pearsonothuria graeffei (fuc-Pg), a type of sulfated polysaccharides with a repeating structure, was shown to be a potential functional food ingredient. In this work, we investigated the effects of fuc-Pg on gut microbiota dysbiosis and metabolic syndromes caused by HFD. Our results indicated that fuc-Pg could reduce weight gains, alleviate hyperlipidemia, and protect the liver from steatosis in HFD-fed mice. Meanwhile, fuc-Pg decreases serum inflammatory cytokines and reduces macrophages infiltrating into adipose tissue. The gut microbiota dysbiosis caused by HFD was alleviated by administration of fuc-Pg, mainly working in the colon. Fuc-Pg increased abundances of Bacteroidetes and Actinobacteria while decreased Firmicutes and Proteobacteria. Our results indicated that fuc-Pg could be a functional food for gut microbiota dysbiosis and metabolic syndromes.