MYB proteins play important roles in the regulation of plant growth, development, and stress responses. Overexpression of BplMYB46 from Betula platyphylla improved plant salt and osmotic tolerances. In the present study, the interaction of eight avian myeloblastosis viral oncogene homolog (MYB) transcription factors with BplMYB46 was investigated using the yeast two-hybrid system, which showed that BplMYB46 could form homodimers and heterodimers with BplMYB6, BplMYB8, BplMYB11, BplMYB12, and BplMYB13. Relative beta-glucuronidase activity and chromatin immunoprecipitation assays showed that the interaction between BplMYB46 and the five MYBs increased the binding of BplMYB46 to the MYBCORE motif. A subcellular localization study showed that these MYBs were all located in the nucleus. Real-time fluorescence quantitative PCR results indicated that the expressions of BplMYB46 and the five MYB genes could be induced by salt and osmotic stress, and the BplMYB46 and BplMYB13 exhibited the most similar expression patterns. BplMYB46 and BplMYB13 co-overexpression in tobacco using transient transformation technology improved tobacco’s tolerance to salt and osmotic stresses compared with overexpressing BplMYB13 or BplMYB46 alone. Taken together, these results demonstrated that BplMYB46 could interact with five other MYBs to form heterodimers that activate the transcription of target genes via an enhanced binding ability to the MYBCORE motif to mediate reactive oxygen species scavenging in response to salt and osmotic stresses.

Lonicera caerulea L. has high nutritional and health value, and it is an important emerging small berry tree species. In this study, the morphology and nutrient composition of 60 cultivars were used to analyze and evaluate the diversity of the genus. Morphological analysis showed that the phenotypic traits of different cultivars had significant differences (p < 0.01). The phenotypic coefficient of variation (PCV) of each trait was 12.42%~84.06%, and the coefficient of genetic variation (GCV) was between 7.07%~71.72%. The analysis of nutrient content showed significant differences among the cultivars (p < 0.01). The PCV of each trait was 3.95%~96.10%, and the GCV was 0.13%~32.83%. Based on breeding objectives, cultivars with excellent growth and leaf quantitative traits, fruit quantitative traits and nutrient contents were selected through the method of comprehensive analysis of multiple characters. Traits of the selected varieties were all above average, and specific genetic gain was higher. At the same time, the selection of varieties was carried out according to flowering and fruiting phenology, which provided an indication for the breeding of improved varieties. In this study, growth, leaf and fruit quantitative traits, phenological period and nutrient components of different cultivars provided valuable information for the breeding of improved varieties.

Lonicera caerulea is a wild fruit species with high edible and medicinal value. However, the molecular regulation and metabolic mechanisms of L. caerulea under salt stress are still unclear. Salt stress causes damage to the cell membrane of L. caerulea and induces changes in malondialdehyde content, relative electrolyte leakage, leaves’ stomatal opening, and the water loss rate. It also increases the activity of antioxidant enzymes and the content of soluble sugars. A comprehensive transcriptomic and metabolomic analysis of L. caerulea exposed to salt stress at four different (treatment) time intervals yielded a total of 99,574 unigenes and 1375 metabolites. Among these, 4081, 4042, and 4403 differentially expressed genes (DEGs) were identified in 12 transcriptomes, while 776, 832, and 793 differentially accumulated metabolites (DAMs) were detected in 12 metabolomes. The DEGs play important roles in several signaling pathways, including MAPK signaling, fatty acid metabolism, starch and sucrose metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction. KEGG pathway enrichment analysis revealed that these DEGs and DAMs are associated with flavonoid and lipid biosynthesis pathways. The combined transcriptomic and metabolomic analyses suggest that flavonoid and fatty acid compounds may be involved in regulating plant responses to salt stress. These findings will lay the foundation for the selection of L. caerulea germplasm resources and the expansion of its cultivation area. These research findings will lay the foundation for the cultivation of salt-tolerant new varieties of L. caerulea and their planting in saline–alkali soils.

The Short Internodes-Related Sequence (SRS) family is a class of transcription factors unique to plants that are essential for controlling their growth, development, and stress responses. Nevertheless, information regarding the characterization and biological function of poplar SRS family members remains limited. In this study, we identified 10 members of the SRS gene family in the genome of Populus tremula using bioinformatics, distributed on seven chromosomes and named PtSRS01-PtSRS10 based on their locations. Our phylogenetic analysis results indicated that PtSRS genes can be categorized into five subfamilies and that members of each subfamily have similar gene structures and motifs. Collinearity analysis indicated that the expansion of the PtSRS gene family is caused by segmental duplication and is influenced by purifying selection during its evolutionary process. Cis-acting element analysis revealed that PtSRS was enriched in cis-acting elements related to growth and development, light response, hormone induction, and stress response. Quantitative real-time PCR revealed that drought and salt (NaCl) treatments affected the expression of several PtSRS genes, with PtSRS04 and PtSRS05 being the two genes with the most significant expression levels, with PtSRS04 showing a 700-fold increase in relative gene expression level after 8 d of drought stress and the PtSRS05 gene showing a 38-fold increase in gene expression level at 48 h of NaCl stress, suggesting that they could be crucial in salt and drought stress. The results presented herein provide a theoretical basis for subsequent in-depth studies on the involvement of poplar SRS gene family members in drought and salt stress resistance.