Horticulture research 

About: Horticulture research is an academic journal published by Nature Portfolio. The journal publishes majorly in the area(s): Biology & Medicine. It has an ISSN identifier of 2052-7276. It is also open access. Over the lifetime, 1316 publications have been published receiving 26342 citations. The journal is also known as: Yuanyi yanjiu.

Carotenoid metabolism and regulation in horticultural crops.

Abstract: Carotenoids are a diverse group of pigments widely distributed in nature. The vivid yellow, orange, and red colors of many horticultural crops are attributed to the overaccumulation of carotenoids, which contribute to a critical agronomic trait for flowers and an important quality trait for fruits and vegetables. Not only do carotenoids give horticultural crops their visual appeal, they also enhance nutritional value and health benefits for humans. As a result, carotenoid research in horticultural crops has grown exponentially over the last decade. These investigations have advanced our fundamental understanding of carotenoid metabolism and regulation in plants. In this review, we provide an overview of carotenoid biosynthesis, degradation, and accumulation in horticultural crops and highlight recent achievements in our understanding of carotenoid metabolic regulation in vegetables, fruits, and flowers.

Genome Triplication Drove the Diversification of Brassica Plants

Abstract: The genus Brassica belongs to the plant family Brassicaceae, which includes many important crop species that are used as oilseed, condiments, or vegetables throughout the world. Brassica plants comprise many diverse species, and each species contains rich morphotypes showing extreme traits. Brassica species experienced an extra whole genome triplication (WGT) event compared with the model plant Arabidopsis thaliana. Whole genome sequencing of the Brassica species Brassica rapa, Brassica oleracea and others demonstrated that WGT plays an important role in the speciation and morphotype diversification of Brassica plants. Comparative genomic analysis based on the genome sequences of B. rapa and A. thaliana clearly identified the WGT event and further demonstrated that the translocated Proto-Calepine Karyotype (tPCK, n=7) was the diploid ancestor of the three subgenomes in B. rapa. Following WGT, subsequent extensive genome fractionation, block reshuffling and chromosome reduction accompanied by paleocentromere descent from the three tPCK subgenomes during the rediploidization process produced stable diploid species. Genomic rearrangement of the diploid species and their hybridization then contributed to Brassica speciation. The subgenome dominance effect and biased gene retention, such as the over-retention of auxin-related genes after WGT, promoted functional gene evolution and thus propelled the expansion of rich morphotypes in the Brassica species. In conclusion, the WGT event initiated subsequent genomic and gene-level evolution, which further drove Brassica speciation and created rich morphotypes in each species.

The bZIP transcription factor MdHY5 regulates anthocyanin accumulation and nitrate assimilation in apple.

Abstract: The basic leucine zipper (bZIP) transcription factor HY5 plays a multifaceted role in plant growth and development. Here the apple MdHY5 gene was cloned based on its homology with Arabidopsis HY5. Expression analysis demonstrated that MdHY5 transcription was induced by light and abscisic acid treatments. Electrophoretic mobility shift assays and transient expression assays subsequently showed that MdHY5 positively regulated both its own transcription and that of MdMYB10 by binding to E-box and G-box motifs, respectively. Furthermore, we obtained transgenic apple calli that overexpressed the MdHY5 gene, and apple calli coloration assays showed that MdHY5 promoted anthocyanin accumulation by regulating expression of the MdMYB10 gene and downstream anthocyanin biosynthesis genes. In addition, the transcript levels of a series of nitrate reductase genes and nitrate uptake genes in both wild-type and transgenic apple calli were detected. In association with increased nitrate reductase activities and nitrate contents, the results indicated that MdHY5 might be an important regulator in nutrient assimilation. Taken together, these results indicate that MdHY5 plays a vital role in anthocyanin accumulation and nitrate assimilation in apple. The regulatory gene HY5 plays an important role in two biochemical pathways controlling fruit quality and coloration in apple. The gene HY5 has long been recognized as a key regulator of other genes, controlling multiple processes in plant growth and development. A team from Shandong Agricultural University, China, led by Xiao-Fei Wang and Yu-Jin Hao, investigated the gene‘s action in apples, one of the world‘s most important fruit crops. They found that HY5 strongly influences the production of pigments known as anthocyanins, which help give apples their appealing color. They also found evidence that it is involved in regulating nitrogen uptake, a crucial process for plant growth, and that its action is light-activated. These results may prove useful to breeders engineering better quality and more attractive apples for the consumer market.

Improved Brassica rapa reference genome by single-molecule sequencing and chromosome conformation capture technologies.

Abstract: Brassica rapa comprises several important cultivated vegetables and oil crops. Current reference genome assemblies of Brassica rapa are quite fragmented and not highly contiguous, thereby limiting extensive genetic and genomic analyses. Here, we report an improved assembly of the B. rapa genome (v3.0) using single-molecule sequencing, optical mapping, and chromosome conformation capture technologies (Hi-C). Relative to the previous reference genomes, our assembly features a contig N50 size of 1.45 Mb, representing a ~30-fold improvement. We also identified a new event that occurred in the B. rapa genome ~1.2 million years ago, when a long terminal repeat retrotransposon (LTR-RT) expanded. Further analysis refined the relationship of genome blocks and accurately located the centromeres in the B. rapa genome. The B. rapa genome v3.0 will serve as an important community resource for future genetic and genomic studies in B. rapa. This resource will facilitate breeding efforts in B. rapa, as well as comparative genomic analysis with other Brassica species.

Breeding better cultivars, faster: applications of new technologies for the rapid deployment of superior horticultural tree crops.

Abstract: Woody perennial plants, including trees that produce fruits and nuts of horticultural value, typically have long breeding cycles, and development and introduction of improved cultivars by plant breeders may require many breeding cycles and dozens of years. However, recent advances in biotechnologies and genomics have the potential to accelerate cultivar development greatly in all crops. This mini-review summarizes approaches to reduce the number and the duration of breeding cycles for horticultural tree crops, and outlines the challenges that remain to implement these into efficient breeding pipelines.