Kiwifruit spatiotemporal multiomics networks uncover key tissue-specific regulatory processes throughout the life cycle.

Kiwifruit (Actinidia chinensis), a recently commercialized horticultural crop, is rich in various nutrient compounds. However, the regulatory networks controlling the dynamic changes in key metabolites among different tissues remain largely unknown. Here, high-resolution spatiotemporal datasets obtained by ultraperformance liquid chromatography-tandem mass spectrometry methodology and RNA-seq were employed to investigate the dynamic changes in the metabolic and transcriptional landscape of major kiwifruit tissues across different developmental stages, including from fruit skin, outer pericarp, inner pericarp, and fruit core.

Multi-omics analyses reveal the importance of chromoplast plastoglobules in carotenoid accumulation in citrus fruit.

Chromoplasts act as a metabolic sink for carotenoids, in which plastoglobules serve as versatile lipoprotein particles. PGs in chloroplasts have been characterized. However, the features of PGs from non-photosynthetic plastids are poorly understood.

Comparative transcriptomic and plastid development analysis sheds light on the differential carotenoid accumulation in kiwifruit flesh.

Carotenoids are colorful lipophilic isoprenoids synthesized in all photosynthetic organisms which play roles in plant growth and development and provide numerous health benefits in the human diet (precursor of Vitamin A). The commercially popular kiwifruits are golden yellow-fleshed () and green fleshed () cultivars which have a high carotenoid concentration. Understanding the molecular mechanisms controlling the synthesis and sequestration of carotenoids in species is key to increasing nutritional value of this crop via breeding.

Genome-wide characterization of long terminal repeat retrotransposons provides insights into trait evolution of four cucurbit species.

Cucurbits are a diverse plant family that includes economically important crops, such as cucumber, watermelon, melon, and pumpkin. Knowledge of the roles that long terminal repeat retrotransposons (LTR-RTs) have played in diversification of cucurbit species is limited; to add to understanding of the roles of LTR-RTs, we assessed their distributions in four cucurbit species. We identified 381, 578, 1086, and 623 intact LTR-RTs in cucumber (Cucumis sativus L.

Overexpression of increases fruit skin and flesh carotenoid content and reveals associated transcription factors in apple ( × ).

Knowledge of the transcriptional regulation of the carotenoid metabolic pathway is still emerging and here, we have misexpressed a key biosynthetic gene in apple to highlight potential transcriptional regulators of this pathway. We overexpressed phytoene synthase (), which controls the key rate-limiting biosynthetic step, in apple and analyzed its effects in transgenic fruit skin and flesh using two approaches. Firstly, the effects of PSY overexpression on carotenoid accumulation and gene expression was assessed in fruit at different development stages.

A simple and efficient protocol for transient transformation of sliced grape berries.

Grape is an economically important crop but recalcitrant to Agrobacterium-mediated genetic transformation and in vitro regeneration. Here, we have developed a protocol for transient transformation of grapes by investigating the effects of explant pre-culture and duration of vacuum infiltration on transformation efficiency. Using sliced grape berries of "Shine-Muscat" (Vitis labrusca × Vitis vinifera) between the end of fruit expansion phase and the mature stage as explants, we firstly compared the effect of pre-culture explants into a susceptible state (incubation on Murashige and Skoog (MS) agar plate in the dark at 25 ± 1 °C for 48 h) with no pre-culture and then tested different vacuum infiltration times on transformation efficiency using β-glucuronidase (GUS) reporter system.

Elevating fruit carotenoid content in apple (Malus x domestica Borkh).

Carotenoid compounds accumulate to confer coloration to plant tissues and have some established health benefits in humans. These pigments have antioxidant properties and are precursors of vitamin A, which is important for human vision. Apple is widely consumed globally, but most commercial apple cultivars have low fruit carotenoid content because these pigments accumulate mostly in the fruit skin rather than the flesh (the majority of the edible portion).

Transposon insertions regulate genome-wide allele-specific expression and underpin flower colour variations in apple (Malus spp.).

Allele-specific expression (ASE) can lead to phenotypic diversity and evolution. However, the mechanisms regulating ASE are not well understood, particularly in woody perennial plants. In this study, we investigated ASE genes in the apple cultivar 'Royal Gala' (RG).

PpIAA1 and PpERF4 form a positive feedback loop to regulate peach fruit ripening by integrating auxin and ethylene signals.

The signaling pathways of both auxin and ethylene regulate peach fruit ripening via the Aux/IAA and ERF transcription factors, respectively. However, the molecular mechanisms that coordinate both auxin and ethylene signals during peach fruit ripening remain unclear. In this study, we show that PpIAA1 and PpERF4 act as key players in a positive feedback loop, and promote peach fruit ripening by directly binding to and enhancing the activity of target gene promoters.

Optimizing pollencounter for high throughput phenotyping of pollen quality in tomatoes.

The macro "PollenCounter" in ImageJ was initially developed to assess pollen viability in grapevine. We set out to see if PollenCounter could be used to assess pollen number and viability in tomatoes.•We tested different optimization scenarios by adjusting the pollen size (100-900, 200-900 pixel) and circularity of pollen grains (0.

The involvement of in light-induced anthocyanin accumulation via the activation of through binding to tandem G-boxes in its promoter.

To gain insight into how anthocyanin biosynthesis is controlled by light in fruit, transcriptome and metabolome analyses were performed in the Chinese sand pear cultivar "Mantianhong" () after bagging and bag removal. We investigated transcriptional and metabolic changes and gene-metabolite correlation networks. Correlation tests of anthocyanin content and transcriptional changes revealed that 1,530 transcripts were strongly correlated with 15 anthocyanin derivatives (  > 0.

A kiwifruit (Actinidia deliciosa) R2R3-MYB transcription factor modulates chlorophyll and carotenoid accumulation.

MYB transcription factors (TFs) regulate diverse plant developmental processes and understanding their roles in controlling pigment accumulation in fruit is important for developing new cultivars. In this study, we characterised kiwifruit TFMYB7, which was found to activate the promoter of the kiwifruit lycopene beta-cyclase (AdLCY-β) gene that plays a key role in the carotenoid biosynthetic pathway. To determine the role of MYB7, we analysed gene expression and metabolite profiles in Actinidia fruit which show different pigment profiles.

A manually annotated Actinidia chinensis var. chinensis (kiwifruit) genome highlights the challenges associated with draft genomes and gene prediction in plants.

Background: Most published genome sequences are drafts, and most are dominated by computational gene prediction. Draft genomes typically incorporate considerable sequence data that are not assigned to chromosomes, and predicted genes without quality confidence measures. The current Actinidia chinensis (kiwifruit) 'Hongyang' draft genome has 164 Mb of sequences unassigned to pseudo-chromosomes, and omissions have been identified in the gene models.

Carotenoid accumulation in durian (Durio zibethinus) fruit is affected by ethylene via modulation of carotenoid pathway gene expression.

Carotenoid content in durian (Durio zibethinus) fruit is an important aspect of fruit quality, with different cultivars distinguished by differing pigmentation. We have studied the dependence of carotenogenesis on ethylene. Fruit of the cultivar 'Chanee' harvested at the mature stage were either left untreated (controls), treated with 1-methylcyclopropene (1-MCP) for 12 h, or treated with application of an aqueous ethephon solution to the stem end, or treated for 12 h with 1-MCP followed by ethephon application.

The Phytoene synthase gene family of apple (Malus x domestica) and its role in controlling fruit carotenoid content.

Background: Carotenoid compounds play essential roles in plants such as protecting the photosynthetic apparatus and in hormone signalling. Coloured carotenoids provide yellow, orange and red colour to plant tissues, as well as offering nutritional benefit to humans and animals. The enzyme phytoene synthase (PSY) catalyses the first committed step of the carotenoid biosynthetic pathway and has been associated with control of pathway flux.

Control of carotenoid biosynthesis through a heme-based cis-trans isomerase.

Plants synthesize carotenoids, which are essential for plant development and survival. These metabolites also serve as essential nutrients for human health. The biosynthetic pathway for all plant carotenoids occurs in chloroplasts and other plastids and requires 15-cis-ζ-carotene isomerase (Z-ISO).

Metabolic and gene expression analysis of apple (Malus x domestica) carotenogenesis.

Carotenoid accumulation confers distinct colouration to plant tissues, with effects on plant response to light and as well as health benefits for consumers of plant products. The carotenoid pathway is controlled by flux of metabolites, rate-limiting enzyme steps, feed-back inhibition, and the strength of sink organelles, the plastids, in the cell. In apple (Malus × domestica Borkh), fruit carotenoid concentrations are low in comparison with those in other fruit species.

The kiwifruit lycopene beta-cyclase plays a significant role in carotenoid accumulation in fruit.

The composition of carotenoids, along with anthocyanins and chlorophyll, accounts for the distinctive range of colour found in the Actinidia (kiwifruit) species. Lutein and beta-carotene are the most abundant carotenoids found during fruit development, with beta-carotene concentration increasing rapidly during fruit maturation and ripening. In addition, the accumulation of beta-carotene and lutein is influenced by the temperature at which harvested fruit are stored.

Analysis of expressed sequence tags from Actinidia: applications of a cross species EST database for gene discovery in the areas of flavor, health, color and ripening.

Background: Kiwifruit (Actinidia spp.) are a relatively new, but economically important crop grown in many different parts of the world. Commercial success is driven by the development of new cultivars with novel consumer traits including flavor, appearance, healthful components and convenience.

Gain-of-function phenotypes of many CLAVATA3/ESR genes, including four new family members, correlate with tandem variations in the conserved CLAVATA3/ESR domain.

Secreted peptide ligands are known to play key roles in the regulation of plant growth, development, and environmental responses. However, phenotypes for surprisingly few such genes have been identified via loss-of-function mutant screens. To begin to understand the processes regulated by the CLAVATA3 (CLV3)/ESR (CLE) ligand gene family, we took a systems approach to gene identification and gain-of-function phenotype screens in transgenic plants.

Down-regulation of TM29, a tomato SEPALLATA homolog, causes parthenocarpic fruit development and floral reversion.

We have characterized the tomato (Lycopersicon esculentum Mill.) MADS box gene TM29 that shared a high amino acid sequence homology to the Arabidopsis SEP1, 2, and 3 (SEPALLATA1, 2, and 3) genes. TM29 showed similar expression profiles to SEP1, with accumulation of mRNA in the primordia of all four whorls of floral organs.