The MADS-box protein SlTAGL1 regulates a ripening-associated SlDQD/SDH2 involved in flavonoid biosynthesis and resistance against Botrytis cinerea in post-harvest tomato fruit.

3-Dehydroquinate dehydratase/shikimate dehydrogenase (DQD/SDH) is a key rate-limiting enzyme that catalyzes the synthesis of the shikimate, which is an important metabolic intermediate in plants and animals. However, the function of SlDQD/SDH family genes in tomato (Solanum lycopersicum) fruit metabolites is still unknown. In the present study, we identified a ripening-associated SlDQD/SDH member, SlDQD/SDH2, that plays a key role in shikimate and flavonoid metabolism.

Genome-wide characterization of the tomato GASA family identifies SlGASA1 as a repressor of fruit ripening.

Gibberellins (GAs) play crucial roles in a wide range of developmental processes and stress responses in plants. However, the roles of GA-responsive genes in tomato () fruit development remain largely unknown. Here, we identify 17 () family genes in tomato.

SlERF.F12 modulates the transition to ripening in tomato fruit by recruiting the co-repressor TOPLESS and histone deacetylases to repress key ripening genes.

Ethylene response factors (ERFs) are downstream components of ethylene-signaling pathways known to play critical roles in ethylene-controlled climacteric fruit ripening, yet little is known about the molecular mechanism underlying their mode of action. Here, we demonstrate that SlERF.F12, a member of the ERF.

Ethylene response factor AcERF91 affects ascorbate metabolism via regulation of GDP-galactose phosphorylase encoding gene (AcGGP3) in kiwifruit.

Kiwifruit is known as 'the king of vitamin C' because of the high content of ascorbic acid (AsA) in the fruit. Deciphering the regulatory network and identification of the key regulators mediating AsA biosynthesis is vital for fruit nutrition and quality improvement. To date, however, the key transcription factors regulating AsA metabolism during kiwifruit developmental and ripening processes remains largely unknown.

Molecular basis of the formation and removal of fruit astringency.

Astringency is a dry puckering mouthfeel mainly generated by the binding of tannins with proteins in the mouth. Tannins confer benefits such as resistance to biotic stresses and have antioxidant activity, and moderate concentrations of tannins can improve the flavor of fruits or their products. However, fruits with high contents of tannins have excessive astringency, which is undesirable.

Integrative analyses of metabolome and genome-wide transcriptome reveal the regulatory network governing flavor formation in kiwifruit (Actinidia chinensis).

Soluble sugars, organic acids and volatiles are important components that determine unique fruit flavor and consumer preferences. However, the metabolic dynamics and underlying regulatory networks that modulate overall flavor formation during fruit development and ripening remain largely unknown for most fruit species. In this study, by integrating flavor-associated metabolism and transcriptome data from 12 fruit developmental and ripening stages of Actinidia chinensis cv Hongyang, we generated a global map of changes in the flavor-related metabolites throughout development and ripening of kiwifruit.

Genome-Wide Identification of DNA Methylases and Demethylases in Kiwifruit ().

DNA methylation plays an important role in a wide range of developmental and physiological processes in plants. It is primarily catalyzed and regulated by cytosine-5 DNA methyltransferases (C5-MTases) and a group of DNA glycosylases that act as demethylases. To date, no genome-scale analysis of the two kiwifruit () families has been undertaken.

Nonaqueous fractionation and overexpression of fluorescent-tagged enzymes reveals the subcellular sites of L-theanine biosynthesis in tea.

l-Theanine is a specialized metabolite in the tea (Camellia sinensis) plant which can constitute over 50% of the total amino acids. This makes an important contribution to tea functionality and quality, but the subcellular location and mechanism of biosynthesis of l-theanine are unclear. Here, we identified five distinct genes potentially capable of synthesizing l-theanine in tea.

Like Heterochromatin Protein 1b represses fruit ripening via regulating the H3K27me3 levels in ripening-related genes in tomato.

Polycomb group (PcG) proteins play vital roles in plant development via epigenetically repressing the transcription of target genes. However, to date, their function in fruit ripening is largely unknown. Combining reverse genetic approaches, physiological methods, yeast two-hybrid, co-immunoprecipitation, and chromatin immunoprecipitation assays, we show that Like Heterochromatin Protein 1b (SlLHP1b), a tomato Polycomb Repressive Complex 1 (PRC1)-like protein with a ripening-related expression pattern, represses fruit ripening via colocalization with epigenetic mark H3K27me3.

The persimmon ( Cheng) genome provides new insights into the inheritance of astringency and ancestral evolution.

Persimmon () is an oriental perennial woody fruit tree whose popular fruit is produced and consumed worldwide. The persimmon fruit is unique because of the hyperaccumulation of proanthocyanidins during fruit development, causing the mature fruit of most cultivars to have an astringent taste. In this study, we obtained a chromosome-scale genome assembly for 'Youshi' (, 2n = 2x = 30), the diploid species of persimmon, by integrating Illumina sequencing, single-molecule real-time sequencing, and high-throughput chromosome conformation capture techniques.

Effect of Ethylene on Cell Wall and Lipid Metabolism during Alleviation of Postharvest Chilling Injury in Peach.

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.

Genome-Wide Identification and Functional Analysis of Carboxylesterase and Methylesterase Gene Families in Peach ( L. Batsch).

Carboxylesterases (CXE) and methylesterases (MES) are hydrolytic enzymes that act on carboxylic esters and are involved in plant metabolic processes and defense responses. A few functions of plant and genes have been identified but very little information is available about the role of most members. We made a comprehensive study of this gene family in a commercially important species, peach ( L.

Lycopene cyclases determine high α-/β-carotene ratio and increased carotenoids in bananas ripening at high temperatures.

Bananas are a recommended food source to alleviate vitamin A deficiency because they contain a high ratio of provitamin A precursors. The objective of this study was to investigate carotenoid accumulation pattern in banana fruits during postharvest ripening and the mechanisms regulating this process. Ripe banana pulp had an unusually high α-/β-carotene ratio (1.

Microscopic Analyses of Fruit Cell Plastid Development in Loquat () during Fruit Ripening.

Plastids are sites for carotenoid biosynthesis and accumulation, but detailed information on fruit plastid development and its relation to carotenoid accumulation remains largely unclear. Here, using Baisha (BS; white-fleshed) and Luoyangqing (LYQ; red-fleshed) loquat (), a detailed microscopic analysis of plastid development during fruit ripening was carried out. In peel cells, chloroplasts turned into smaller chromoplasts in both cultivars, and the quantity of plastids in LYQ increased by one-half during fruit ripening.

A critical evaluation of the role of ethylene and MADS transcription factors in the network controlling fleshy fruit ripening.

Contents Summary 1724 I. Introduction 1725 II. Ripening genes 1725 III.

Transcriptomic changes triggered by carotenoid biosynthesis inhibitors and role of Citrus sinensis phosphate transporter 4;2 (CsPHT4;2) in enhancing carotenoid accumulation.

Carotenoid accumulation and chromoplast development in orange were perturbed by carotenoid inhibitors, and candidate genes were identified via transcriptomic analysis. The role of CsPHT4;2 in enhancing carotenoid accumulation was revealed. Carotenoids are important plant pigments and their accumulation can be affected by biosynthesis inhibitors, but the genes involved were largely unknown.

Cytological and molecular characterization of carotenoid accumulation in normal and high-lycopene mutant oranges.

Ripe Cara Cara sweet orange contains 25 times as much carotenoids in flesh as Newhall sweet orange, due to high accumulation of carotenes, mainly phytoene, lycopene and phytofluene. Only yellow globular chromoplasts were observed in Newhall flesh. Distinct yellow globular and red elongated crystalline chromoplasts were found in Cara Cara but only one type of chromoplast was present in each cell.

Transcriptomic and metabolic analyses provide new insights into chilling injury in peach fruit.

Low temperature conditioning (LTC) alleviates peach fruit chilling injury but the underlying molecular basis is poorly understood. Here, changes in transcriptome, ethylene production, flesh softening, internal browning and membrane lipids were compared in fruit maintained in constant 0 °C and LTC (pre-storage at 8 °C for 5 d before storage at 0 °C). Low temperature conditioning resulted in a higher rate of ethylene production and a more rapid flesh softening as a result of higher expression of ethylene biosynthetic genes and a series of cell wall hydrolases.

Genetic improvement of tomato by targeted control of fruit softening.

Controlling the rate of softening to extend shelf life was a key target for researchers engineering genetically modified (GM) tomatoes in the 1990s, but only modest improvements were achieved. Hybrids grown nowadays contain 'non-ripening mutations' that slow ripening and improve shelf life, but adversely affect flavor and color. We report substantial, targeted control of tomato softening, without affecting other aspects of ripening, by silencing a gene encoding a pectate lyase.

Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses.

γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency.

Involvement of multiple phytoene synthase genes in tissue- and cultivar-specific accumulation of carotenoids in loquat.

Differences in carotenoid accumulation between tissues and cultivars is common in plants. White-fleshed loquat cultivars had low levels of carotenoids in the flesh, but accumulated carotenoids in peel when ripe, and the leaves accumulated similar carotenoids to those in the red-fleshed loquat cultivars. The catalytic activity and expression patterns of four phytoene synthase (PSY) genes, EjPSY1, EjPSY2A, EjPSY2B, and EjPSY3, were analysed to understand their roles in different loquat (Eriobotrya japonica Lindl.