园艺研究(英文)最新文献

[This corrects the article DOI: 10.1093/hr/uhad050.].

[This corrects the article DOI: 10.1093/hr/uhac113.].

With advances in next-generation sequencing technologies, various marker genotyping systems have been developed for genomics-based approaches such as genomic selection (GS) and genome-wide association study (GWAS). As new genotyping platforms are developed, data from different genotyping platforms must be combined. However, the potential use of combined data for GS and GWAS has not yet been clarified. In this study, the accuracy of genomic prediction (GP) and the detection power of GWAS increased for most fruit quality traits of apples when using combined data from different genotyping systems, Illumina Infinium single-nucleotide polymorphism array and genotyping by random amplicon sequencing-direct (GRAS-Di) systems. In addition, the GP model, which considered the inbreeding effect, further improved the accuracy of the seven fruit traits. Runs of homozygosity (ROH) islands overlapped with the significantly associated regions detected by the GWAS for several fruit traits. Breeders may have exploited these regions to select promising apples by breeders, increasing homozygosity. These results suggest that combining genotypic data from different genotyping platforms benefits the GS and GWAS of fruit quality traits in apples. Information on inbreeding could be beneficial for improving the accuracy of GS for fruit traits of apples; however, further analysis is required to elucidate the relationship between the fruit traits and inbreeding depression (e.g. decreased vigor).

The secondary metabolism of plants is an essential life process enabling organisms to navigate various stages of plant development and cope with ever-changing environmental stresses. Secondary metabolites, abundantly found in nature, possess significant medicinal value. Among the regulatory mechanisms governing these metabolic processes, alternative splicing stands out as a widely observed post-transcriptional mechanism present in multicellular organisms. It facilitates the generation of multiple mRNA transcripts from a single gene by selecting different splicing sites. Selective splicing events in plants are widely induced by various signals, including external environmental stress and hormone signals. These events ultimately regulate the secondary metabolic processes and the accumulation of essential secondary metabolites in plants by influencing the synthesis of primary metabolites, hormone metabolism, biomass accumulation, and capillary density. Simultaneously, alternative splicing plays a crucial role in enhancing protein diversity and the abundance of the transcriptome. This paper provides a summary of the factors inducing alternative splicing events in plants and systematically describes the progress in regulating alternative splicing with respect to different secondary metabolites, including terpenoid, phenolic compounds, and nitrogen-containing compounds. Such elucidation offers critical foundational insights for understanding the role of alternative splicing in regulating plant metabolism and presents novel avenues and perspectives for bioengineering.

Mango (Mangifera indica L.) has been widely cultivated as a culturally and economically significant fruit tree for roughly 4000 years. Despite its rich history, little is known about the crop's domestication, genomic variation, and the genetic loci underlying agronomic traits. This study employs the whole-genome re-sequencing of 224 mango accessions sourced from 22 countries, with an average sequencing depth of 16.37×, to explore their genomic variation and diversity. Through phylogenomic analysis, M. himalis J.Y. Liang, a species grown in China, was reclassified into the cultivated mango group known as M. indica. Moreover, our investigation of mango population structure and differentiation revealed that Chinese accessions could be divided into two distinct gene pools, indicating the presence of independent genetic diversity ecotypes. By coupling genome-wide association studies with analyses of genotype variation patterns and expression patterns, we identified several candidate loci and dominant genotypes associated with mango flowering capability, fruit weight, and volatile compound production. In conclusion, our study offers valuable insights into the genetic differentiation of mango populations, paving the way for future agronomic improvements through genomic-assisted breeding.

Postharvest decay, primarily caused by pathogenic fungi in ripening fruits and fresh vegetables, poses a challenge to agricultural sustainability and results in significant economic losses. The regulation of the fruit ripening by DNA methylation has been well demonstrated, while defense response of fruit underlying epigenetic regulation against postharvest decay remains uncertain. In the present study, treatment of tomato fruits with the DNA methyltransferase inhibitor 5-Azacytidine (5-Aza) notably decreased their susceptibility to gray mold. Following 5-Aza treatment, we observed a substantial increase in activities of chitinase (CHI) and glucanase (GLU) in tomato fruits, as well as an increase in the expression of the dicer-like SlDCL2 gene family. Suppression of SlDCL2c through double-stranded RNA-induced RNA interference (RNAi) resulted in a decrease in the expression of chitinases CHI3, CHI9, Class V chitinase, and endochitinase 4 by 71%, 29%, 55%, 64%, as well as glucanases Cel1, Cel2, and GluB by 19%, 93%, and 87%, respectively. This was accompanied by decreased activities of resistance-related enzymes, including CHI and GLU. The expression levels of genes phenylalanine ammonia-lyase PAL2, peroxidase POD 12, POD P7, CCR1, CYP84A2, and COMT in phenylpropanoid biosynthesis pathway also decreased by 33%, 53%, 18%, 50%, 30%, and 24% in SlDCL2c-RNAi fruit, resulting in decreased activities of PAL and POD. Consequently, the lesion diameter of gray mold in SlDCL2c-RNAi fruit increased by 55% compared to the control group. Overall, the present study indicated that DNA methyltransferase inhibitor 5-Aza reduces susceptibility of tomato fruit to gray mold through regulation of DCL2c-mediated inducible defense response.

Sinojackia Hu represents the first woody genus described by Chinese botanists, with all species classified as endangered ornamental plants endemic to China. Their characteristic spindle-shaped fruits confer high ornamental value to the plants, making them favored in gardens and parks. Nevertheless, the fruits likely pose a germination obstacle, contributing to the endangered status of this lineage. Here we report the chromosome-scale genome of S. xylocarpa, and explore the mechanisms underlying its endangered status, as well as its population dynamics throughout evolution. Population genomic analysis has indicated that S. xylocarpa experienced a bottleneck effect following the recent glacial period, leading to a continuous population reduction. Examination of the pericarp composition across six stages of fruit development revealed a consistent increase in the accumulation of lignin and fiber content, responsible for the sturdiness of mature fruits' pericarps. At molecular level, enhanced gene expression in the biosynthesis of lignin, cellulose and hemicellulose was detected in pericarps. Therefore, we conclude that the highly lignified and fibrotic pericarps of S. xylocarpa, which inhibit its seed germination, should be its threatening mechanism, thus proposing corresponding strategies for improved conservation and restoration. This study serves as a seminal contribution to conservation biology, offering valuable insights for the study of other endangered ornamental plants.