OsGSK2 directly interacts with and destabilizes OsJAZ4 to activate JA-mediated defense signaling.

Sex determination and sex differentiation of plants are important physiological processes of plant development. Mulberry (Morus indica L.) is an important economic tree being cultivated in sericulture countries, and mulberry leaf is commonly used for sericulture. The transcriptomic and metabolomic differences between the staminate flowers (SFs) and pistillate flowers (PFs) of mulberry were investigated by RNA sequencing and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Overall, we uncovered 4,230 genes and 209 metabolites are significantly differentially expressed between the SFs and PFs of mulberry. The combined transcriptomic and metabolomic analysis revealed these differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) are involved in flavonoid biosynthesis, galactose metabolism, plant–pathogen interaction, and starch and sucrose metabolism, and these detected DEGs and DEMs may be associated with sex differentiation of mulberry through the regulation of the enrichment pathways, such as the MAPK pathway, flavonoid biosynthesis, galactose metabolism, plant–pathogen interaction, and starch and sucrose metabolism. This study will provide a rich source for the analysis of the molecular mechanism of mulberry sex differentiation processes.

Viruses-mediated genome editing in plants is a powerful strategy to develop plant cultivars with important and novel agricultural traits. Mulberry alba is an important economic tree species that has been cultivated in China for more than 5000 years. So far, only a few viruses have been identified from mulberry trees, and their application potential is largely unknown. Therefore, mining more virus resources from the mulberry tree can pave the way for the establishment of useful engineering tools. In this study, eight old mulberry plants were gathered in seven geographic areas for virome analysis. Based on transcriptome analysis, we discovered three viruses associated with mulberries: Citrus leaf blotch virus isolate mulberry alba 2 (CLBV-ML2), Mulberry-associated virga-like virus (MaVLV), and Mulberry-associated narna-like virus (MaNLV). The genome of CLBV-ML2 was completely sequenced and exhibited high homology with Citriviruses, considered to be members of the genus Citrivirus, while the genomes of MaVLV and MaNLV were nearly completed lacking the 5′ and 3′ termini sequences. We tentatively consider MaVLV to be members of the family Virgaviridae and MaNLV to be members of the genus Narnavirus based on the results of phylogenetic trees. The infection experiments showed that CLBV-ML2 could be detected in the inoculated seedlings of both N. benthamiana and Morus alba, while MaVLV could only be detected in N. benthamiana. All of the infected seedlings did not show obvious symptoms.

To understand the yield and quality of off-season mulberry fruits, which are cultivated in open fields from autumn, the biological characteristics, bioactive compounds, and antioxidant activities of them were analyzed. Compared with mulberry fruits in normal season, the fruit length, fruit diameter, single fruit weight, fruit yield per meter strip, and the fruits yield per 667 m²are significantly lower. The moisture content and juice yield of off-season mulberry fruits are lower than the mulberry fruits in normal season; the pH and soluble solids are higher. The contents of mass fraction of crude protein, total sugar, reducing sugar, total acids, total anthocyanins, and total flavonoids decreased significantly in all batches of off-season mulberry fruits compared with those of normal season. Of off-season mulberry fruits, the contents of glucose, fructose and sucrose, expression, anthocyanin biosynthesis genes, and antioxidant capacity are significantly lower than those in normal season.

Vegetables are essential for maintaining health and preventing diseases due to their nutrients and functional components. However, vegetables specifically designed for blood sugar control are limited. The mulberry tree (Morus) offers potential as a source of functional vegetables with blood-sugar-lowering properties, mainly attributed to 1-Deoxynojirimycin (DNJ). This study compared the nutritional composition and DNJ content in various edible parts of twelve mulberry tree varieties. Sensory evaluations were also conducted to assess sensory attributes. Interestingly, DNJ was found to show a positive correlation with sensory evaluations. Furthermore, the sugar content, particularly sucrose, was significantly higher in tender shoots than leaves, indicating tender shoots as a preferable choice for development as a functional food for blood sugar control. Finally, VM 19 and VM 22 are considered as good candidates for the mulberry vegetable using varieties after sensory evaluation and combining with the DNJ content. These findings provide valuable insights for future research into vegetable selections for blood sugar management and support the potential commercialization of mulberry leaf vegetables as functional food options.

Bud dormancy is a critical adaptive trait in woody plants, essential for enduring harsh winter conditions. The relationship between bud break timing and cold resistance is complex and has been a subject of debate. This study utilizes a Genome-Wide Association Study (GWAS) on 201 natural mulberry populations to identify the MaFAD2 gene, which shows the strongest association with bud break timing. Known for its role in cold resistance, MaFAD2′s link to bud break timing suggests a direct correlation between these traits. Expression analysis of MaFAD2 in mulberry trees indicates peak activity in dormant buds, declining as dormancy ends. Selective sweep analysis on germplasms from contrasting climates reveals positive selection in MaFAD2 in cold-resistant Uzbek germplasms. Overexpression of MaFAD2 in early-budding germplasms significantly delays bud break, confirming its regulatory role. These findings highlight MaFAD2 as a key determinant of cold tolerance variability among mulberry germplasms, with its expression directly correlated with bud break timing. This provides a molecular basis for selecting cold-resistant mulberry germplasms based on bud break timing in breeding programs.