The development of stress tolerance is regulated via the transcriptional regulatory networks involving regulatory homeostasis mediated by protein–DNA interactions. LcNAC73 from Lonicera caerulea was characterized to understand the underlying mechanism of low-temperature and drought stress response in L. caerulea. To better understand the transcription pathway of LcNAC73, we cloned the promoter and screened proteins that could interact with the promoter. Using Yeast one-hybrid, electrophoretic mobility shift, and chromatin immunoprecipitation assays, we found that the LcMYB71 protein specifically bound to the promoter of LcNAC73. The transient transformation and stable transgenic system were used to produce transgenic L. caerulea plants with overexpressed and silenced LcNAC73, elucidating the effect of LcNAC73 on low-temperature and drought stress tolerance. LcNAC73 positively regulated the proline content and enhanced the scavenging of reactive oxygen species, thus improving tolerance to low-temperature and drought stress. Further studies revealed that LcMYB71 and LcNAC73 had similar functions and could improve plant low-temperature and drought tolerance. It is necessary to identify the upstream regulators of a specific gene to characterize gene functions and the associated transcriptional pathways.

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.

Bog bilberry (Vaccinium uliginosum L.) is considered a highly valued non-wood forest product (NWFP) species with edible and medicinal uses in East Asia. It grows in the northeastern forests of China, where stand attributes and structure jointly determine its population characteristics and individuals’ growth. Mapping the regional distributions of its population characteristics can be beneficial in the management of its natural resources, and this mapping should be predicted using machine learning modeling to obtain accurate results. In this study, a total of 60 stands were randomly chosen and screened to investigate natural bog bilberry populations in the eastern mountains of Heilongjiang and Jilin provinces in northeastern China. Individual height, canopy cover area, and fresh weight all increased in stands at higher latitudes, and shoot height was also higher in the eastern stands. The rootstock grove density showed a polynomial quadratic distribution pattern along increasing topographical gradients, resulting in a minimum density of 0.43–0.52 groves m⁻² in stands in the southern part (44.3016° N, 129.4558° E) of Heilongjiang. Multivariate linear regression indicated that the bog bilberry density was depressed by host forest tree species diversity; this was assessed using both the Simpson and Shannon–Wiener indices, which also showed polynomial quadratic distribution patterns (with a modeling minimum of 0.27 and a maximum of 1.21, respectively) in response to the increase in latitude. Structural equation models identified positive contributions of tree diameter at breast height and latitude to shoot height and a negative contribution of longitude to the bog bilberry canopy area. Random forest modeling indicated that dense populations with heavy individuals were distributed in eastern Heilongjiang, and large-canopy individuals were distributed in Mudanjiang and Tonghua. In conclusion, bog bilberry populations showed better attributes in northeastern stands where host forest trees had low species diversity, but the dominant species had strong trunks.

Late spring frost (LSF) poses a threat to temperate forest ecosystems; however, its combined effects with soil properties on triterpene glycosides in the buds of valuable shrubs are still unclear. In this study, natural Aralia elata (Miq.) Seem. populations were investigated in 15 counties in Heilongjiang and Jilin provinces in Northeast China. Buds were sampled in 3–5 cm length and used for determining triterpene glycosides (TGs) of Araloside VI, Araloside V, and 4-F8 (structural analogs) in spring of 2023. LSF in Heilongjiang showed longer days reaching 20 °C (CD20) (6.0 ± 2.5 d), LSF number (NLSF) (1.8 ± 0.5 times) and duration (DLSF) (21.5 ± 5.2 d), and days of temperature rise (DTR) (15.9 ± 3.8 d) compared to Jilin (4.4 ± 0.4 d, 1.2 ± 0.4 times, 17.4 ± 3.9 d, 12.0 ± 3.3 d, respectively). Araloside VI (0.30–0.59%) was positively driven by DLSF but negatively driven by DTR. Araloside V (0.04–0.17%) and 4-F8 (0.09–0.44%) were positively influenced by the lowest temperature, DTR, and CD20, negatively influenced by NLSF, and slightly influenced by organic matter. In LSF-prone regions, soil organic matter and nutrient availability do not need to be enriched, and soil pH should be higher than 5.7 if high TGs are the objective in A. elata buds.