Lushan Yunwu tea (LSYWT) is a famous green tea in China. However, the effects of intercropping tea with flowering cherry on the overall aroma of tea have not been well understood. In this study, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) was used for analysis. A total of 54 volatile compounds from eight chemical classes were identified in tea samples from both the intercropping and pure-tea-plantation groups. Principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), and odor activity value (OAV) methods combined with sensory evaluation identified cis-jasmone, nonanal, and linalool as the key aroma compounds in the intercropping group. Benzaldehyde, α-farnesene, and methyl benzene were identified as the main volatile compounds in the flowering cherry using headspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC–MS). These findings will enrich the research on tea aroma chemistry and offer new insights into the product development and quality improvement of LSYWT.

The Camellia weevil, Curculio chinensis (Chevrolat, 1978), is a dominant oligophagous pest that bores into the fruit of oil-tea Camellia. Genetic differentiation among populations in various hosts can easily occur, which hinders research on pest management. In this study, the genetic structure, genetic diversity, and phylogenetic structure of local C. chinensis populations were examined using 147 individuals (from 6 localities in Jiangxi), based on 2 mitochondrial COI markers. Results indicated that the C. chinensis population in Jiangxi exhibits a high haplotype diversity, especially for the populations from Cam. meiocarpa plantations. Structural differentiation was observed between Haplogroup 1 (73 individuals from Ganzhou, Jian, and Pingxiang) in the monoculture plantations of Cam. meiocarpa and Haplogroup 2 (75 individuals from Pingxiang and Jiujiang) in Cam. oleifera. Two haplogroups have recently undergone a demographic expansion, and Haplogroup 1 has shown a higher number of effective migrants than Haplogroup 2. This suggests that C. chinensis has been spreading from Cam. meiocarpa plantations to other oil-tea Camellia, such as Cam. oleifera. The increased cultivation of oil-tea Camellia in Jiangxi has contributed to a unique genetic structure within the C. chinensis population. This has, in turn, expanded the distribution of C. chinensis and increased migration between populations.

Plants face various biotic and abiotic stress factors during their growth and development, among which, drought is a serious adverse factor that affects yield and quality in agriculture and forestry. Several transcription factors are involved in regulating plant responses to drought stress. In this study, the B-box (BBX) transcription factor CoBBX24 was cloned from Camellia oleifera. This gene encodes a 241-amino-acid polypeptide containing two B-box domains at the N-terminus. A phylogenetic analysis revealed that CoBBX24 and CsBBX24 from Camellia sinensis are in the same branch, with their amino acid sequences being identical by 96.96%. CoBBX24 was localized to the nucleus and acted as a transcriptional activator. The overexpression of CoBBX24 in Arabidopsis heightened its drought tolerance along with a relatively high survival rate, and the rate of water loss in the OX-CoBBX24 lines was observably lower than that of the wild-type. Compared to the wild-type, the root lengths of the OX-CoBBX24 lines were significantly inhibited with abscisic acid. Leaf senescence was delayed in the OX-CoBBX24 lines treated with abscisic acid. The expression of genes related to leaf senescence and chlorophyll breakdown (e.g., SAG12, SAG29, NYC1, NYE1, and NYE2) was downregulated in the OX-CoBBX24 lines. This study indicated that CoBBX24 positively regulates the drought tolerance in Arabidopsis through delayed leaf senescence.

Chrysanthemum morifolium Ramat. is an important ornamental plant, holding dual economic value as a medicinal and edible plant. Jinsi Huangju is a popular healthy tea drink prepared from the large and elegant shaped flowers of C. morifolium. However, the suboptimal accumulation of bioactive flavonoids during conventional harvest (full bloom stage) limits its commercial potential. To elucidate the molecular mechanisms governing flavonoid biosynthesis in Jinsi Huangju flowers and identify key genetic regulators for metabolic engineering, we performed integrated metabolomic and transcriptomic analyses of flowers at distinct developmental stages using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) and RNA-seq. Differential metabolites were screened, and candidate genes were validated via transient transformation assays. Among 2146 identified metabolites, flavonoids were the predominant differential compounds, with accumulation patterns being strongly stage dependent. Thirty-eight flavonoid biosynthetic genes and key transcription factors from the MYB, bHLH, and WD40 families exhibited dynamic expression. The CmMYB8a was confirmed as a positive regulator of flavonoid biosynthesis through transient overexpression. This study deciphers the stage-specific flavonoid accumulation in Jinsi Huangju and identifies CmMYB8a as a pivotal regulatory target. Our findings provide genetic resources for breeding high-flavonoid cultivars via molecular design.

Ning black autumn tea from Jiangxi, China, is often neglected by farmers due to quality decline under hot and arid autumn conditions. In this study, four soil moisture levels (T1–T4, ranging from 32.75% to 18.36%) were established through different sprinkler irrigation frequencies to investigate their effects on tea quality. T2 (27.98% soil moisture) exhibited the highest content of total free amino acids (13.77 mg/g), which was 13.33% higher than that in T4 (12.15 mg/g). Notably, T2 had the highest content of umami amino acids (6.75 mg/g) and the lowest content of bitter amino acids (3.07 mg/g) among all treatments. The total non-esterified catechin content in T2 (18.92 mg/g) was 2.74-fold higher than that in T4 (6.90 mg/g). Among the 55 volatile compounds identified, trans-nerolidol reached its highest odor activity value in T2 (11.77), contributing to a distinctive fruity and floral aroma. Sensory evaluation confirmed that T2 had the highest taste score (89.7), with significantly reduced bitterness and astringency, consistent with its enriched umami amino acids (6.75 mg/g) and lower bitter amino acids (3.07 mg/g). These findings demonstrate that maintaining soil moisture at approximately 28% through moderate sprinkler irrigation effectively balances flavor-related metabolites and improves autumn tea quality, offering a practical strategy to reduce resource waste and increase economic returns.