Horticulture Research

Tomato is considered as the genetic model for climacteric fruits, in which three major players control the fruit ripening process: ethylene, ripening transcription factors, and DNA methylation. The fruitENCODE project has now shown that there are multiple transcriptional circuits regulating fruit ripening in different species, and H3K27me3, instead of DNA methylation, plays a conserved role in restricting these ripening pathways. In addition, the function of the core tomato ripening transcription factors is now being questioned...

Our previous studies indicated that tomato miR482b could negatively regulate the resistance of tomato to Phytophthora infestans and the expression of miR482b was decreased after inoculation with P. infestans . However, the mechanism by which the accumulation of miR482b is suppressed remains unclear. In this study, we wrote a program to identify 89 long noncoding RNA (lncRNA)-originated endogenous target mimics (eTMs) for 46 miRNAs from our RNA-Seq data. Three tomato lncRNAs, lncRNA23468, lncRNA01308 and lncRNA13262, contained conserved eTM sites for miR482b...

Petunia is a very important flower in the global floriculture industry and has played a critical role as a model in plant genetic studies. Owing to limited genetic variability in commercial germplasm, development of novel petunia phenotypes and new varieties has become increasingly difficult. To enrich petunia germplasm and facilitate genetic improvement, it is important to explore genetic variation in progenitor species that may contain highly valuable genes/alleles. In this study, an interspecific recombinant inbred population (168 recombinant inbreds) derived from Petunia integrifolia  ×  P...

The perception and signal transduction of the plant hormone abscisic acid (ABA) are crucial for strawberry fruit ripening, but the underlying mechanism of how ABA regulates ripening-related genes has not been well understood. By employing high-throughput sequencing technology, we comprehensively analyzed transcriptomic and miRNA expression profiles simultaneously in ABA- and nordihydroguaiaretic acid (NDGA, an ABA biosynthesis blocker)-treated strawberry fruits with temporal resolution. The results revealed that ABA regulated many genes in different pathways, including hormone signal transduction and the biosynthesis of secondary metabolites...

SCR/SP11 encodes the male determinant of recognition specificity of self-incompatibility (SI) in Brassica species and is sporophytically expressed in the anther tapetum. Based on dominance relationships in pollen and nucleotide sequence similarity, the S haplotypes in Brassica have been classified as class I or class II, with class-I S haplotypes being dominant over class-II S haplotypes. Here, we revealed that S-22 in B. rapa belonging to class I is recessive to class-II S-44 and class-I S-36 in pollen, whereas it is dominant over S-60 , S-40 , and S-29 based on pollination tests...

Prunus mume is the only plant in the genus Prunus of the Rosaceae family with a characteristic floral scent, and the main component of this scent is benzyl acetate. By contrast, benzyl acetate is not synthesized in Prunus persica flowers. Here, we searched for benzyl alcohol acetyltransferase ( BEAT ) genes based on genomic data from P. mume and P. persica and found 44 unique PmBEATs in P. mume . These genes, which were mainly detected in clusters on chromosomes, originated from gene duplication events during the species evolution of P...

Many studies suggest that there are distinct regulatory processes controlling compound leaf development in different clades of legumes. Loss of function of the LEAFY ( LFY ) orthologs results in a reduction of leaf complexity to different degrees in inverted repeat-lacking clade (IRLC) and non-IRLC species. To further understand the role of LFY orthologs and the molecular mechanism in compound leaf development in non-IRLC plants, we studied leaf development in unifoliate leaf ( un ) mutant, a classical mutant of mungbean ( Vigna radiata L...

Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality. However, the use of a single gene to impact several metabolic pathways is difficult. Here, we show that overexpression of the single gene SlMYB75 ( SlMYB75 -OE) is effective at improving multiple fruit quality traits. In these engineered fruits, the anthocyanin content reached 1.86 mg g-1 fresh weight at the red-ripe stage, and these SlMYB75 -OE tomatoes displayed a series of physiological changes, including delayed ripening and increased ethylene production...

Chrysanthemums are sensitive to waterlogging stress, and the development of screening methods for tolerant germplasms or genes and the breeding of tolerant new varieties are of great importance in chrysanthemum breeding. To understand the genetic basis of waterlogging tolerance (WT) in chrysanthemums, we performed a genome-wide association study (GWAS) using 92,811 single nucleotide polymorphisms (SNPs) in a panel of 88 chrysanthemum accessions, including 64 spray cut and 24 disbud chrysanthemums. The results showed that the average MFVW (membership function value of waterlogging) of the disbud type (0...

Cabbage ( Brassica oleracea var. capitata ) is a biennial plant with strong self-incompatibility and an obligate requirement for prolonged vernalization by exposure to low temperatures to induce flowering. These characteristics significantly increase the difficulty of exploiting novel germplasm induced by physical or chemical mutagens. In this study, we report a CRISPR/Cas9 gene-editing system based on endogenous tRNA processing to induce high efficiency and inheritable mutagenesis in cabbage. Using the phytoene desaturase gene BoPDS , the S-receptor kinase gene BoSRK , and the male-sterility-associated gene BoMS1 as the target genes, multisite and multiple gene mutations were achieved using a construct with tandemly arrayed tRNA-sgRNA architecture to express multiple sgRNAs...

The plant hormone ethylene regulates ripening in climacteric fruits. The phytohormone abscisic acid (ABA) affects ethylene biosynthesis, but whether ethylene influences ABA biosynthesis is unknown. To explore this possibility, we investigated the interactions between the ABA biosynthesis genes PpNCED2/3 and the ethylene response transcription factor PpERF3 in peach fruit. The ABA content increased during fruit maturation and reached a peak at stage S4 III. The increase was greatly inhibited by the ethylene inhibitor 1-MCP, which also suppressed PpERF3 expression...

Apple latent spherical virus (ALSV) vector is a convenient alternative to genetic transformation in horticultural plants, especially in species recalcitrant to genetic transformation. ALSV, an RNA virus, can infect a wide variety of plant species including major horticultural plants without inducing symptoms. Here, methodologies were developed for infection of ALSV vectors to strawberry seedlings and plantlets cultured in vitro. A seed-propagated F1 hybrid strawberry cultivar 'Yotsuboshi' was aseptically grown on half-strength Murashige-Skoog medium for 1 month and true leaves were inoculated with an ALSV RNA preparation by particle bombardment...

Fruit cracking is an important problem in horticultural crop production. Polygalacturonase (SlPG) and expansin (SlEXP1) proteins cooperatively disassemble the polysaccharide network of tomato fruit cell walls during ripening and thereby, enable softening. A Golden 2-like (GLK2) transcription factor, SlGLK2 regulates unripe fruit chloroplast development and results in elevated soluble solids and carotenoids in ripe fruit. To determine whether SlPG, SlEXP1, or SlGLK2 influence the rate of tomato fruit cracking, the incidence of fruit epidermal cracking was compared between wild-type, Ailsa Craig (WT) and fruit with suppressed SlPG and SlEXP1 expression ( pg/exp ) or expressing a truncated nonfunctional Slglk2 ( glk2 )...

Phloem plays a fundamental role in plants by transporting hormones, nutrients, proteins, RNAs, and carbohydrates essential for plant growth and development. However, the identity of the underlying phloem genes and pathways remain enigmatic especially in agriculturally important perennial crops, in part, due to the technical difficulty of phloem sampling. Here, we used two phloem-specific promoters and a translating ribosome affinity purification (TRAP) strategy to characterize the phloem translatome during leaf development at 2, 4, and 6 weeks post vernalization in plum ( Prunus domestica L...

Fleshy fruit ripening is governed by multiple external and internal cues and accompanied by changes in color, texture, volatiles, and nutritional quality traits. While extended shelf-life and increased phytonutrients are desired, delaying ripening via genetic or postharvest means can be accompanied by reduced nutritional value. Here we report that the high pigment 1 ( hp1 ) mutation at the UV-DAMAGED DNA BINDING PROTEIN 1 ( DDB1 ) locus, previously shown to influence carotenoid and additional phytonutrient accumulation via altered light signal transduction, also results in delayed ripening and firmer texture, resulting at least in part from decreased ethylene evolution...

Red skin colour is an important target trait in various pear breeding programmes. In this study, the genetic control of red skin colour was investigated in an interspecific population derived using the descendants of the red sport European pear cultivar 'Max Red Bartlett' (MRB) and the red-blushed Chinese pear cultivar 'Huobali'. Approximately 550 seedlings from nine families were phenotyped for red skin over-colour coverage (Ocolcov) and the intensity of red over-colour (Ocolint) on a 0-9 scale, and genotyped using genotyping-by-sequencing...

Ethylene plays a pivotal role in climacteric fruit ripening; whereas 1-MCP, a non-toxic antagonist of ethylene, prevents ethylene-dependent responses and fruit ripening. In this study, a short-term treatment (1 h) with 400 nL L-1 1-MCP delayed the ripening of harvested papaya. However, long-term application of 1-MCP (400 nL L-1 , 16 h) resulted in abnormal fruit ripening, with the fruits exhibiting normal yellowing without softening, significantly higher cellulose and lignin contents, and intact cell walls (CW)...

A genome-wide association study (GWAS) was applied to detect single nucleotide polymorphisms (SNPs) significantly associated with resistance to Heterodera glycines (HG) also known as the soybean cyst nematode (SCN) in the core collection of common bean, Phaseolus vulgaris . There were 84,416 SNPs identified in 363 common bean accessions. GWAS identified SNPs on chromosome (Chr) 1 that were significantly associated with resistance to HG type 2.5.7. These SNPs were in linkage disequilibrium with a gene cluster orthologous to the three genes at the Rhg1 locus in soybean...

Anthocyanins are a group of secondary metabolites that colour fruit and flowers orange, red, purple or blue depending on a number of factors, such as the basic structure, co-pigmentation, metal ion complexation and vacuolar pH. The biosynthesis of anthocyanin is regulated at the transcriptional level by a group of transcription factors, the MYB-bHLH-WD40 (MBW) complex. In this study, the purple colouration in several kiwifruit ( Actinidia) species was identified and characterised as red cyanidin-based and blue delphinidin-based anthocyanins...

Proanthocyanidins (PAs), also known as "condensed tannins", are colorless metabolites produced through the flavonoid pathway that are involved in stress resistance in plants. Because PAs are involved in the anthocyanin biosynthetic pathway, they play a role in the modification of pigmentation conferred by anthocyanins in ornamental organs. In this study, we isolated the gene and functionally characterized an R2R3-MYB transcription factor (TF), AaMYB3, and a basic helix-loop-helix TF, AabHLH1, from Anthurium andraeanum (Hort...