Aug 2026· Frontiers in Plant Science· Vol 17· 0 citations· 46 references
TL;DR
These findings provide the first comprehensive evidence that alkaloid metabolism, particularly the isoquinoline alkaloid pathway, are transcriptionally and metabolically reprogrammed during blister blight infection, suggesting a potential role in tea’s defense against this pathogen.
Abstract
Blister blight disease, caused by the fungus
Exobasidium vexans
, severely threatens tea production and yield. This study investigates the molecular and metabolic responses of tea to blister blight infection, with a focus on alkaloid metabolism. Here, integrated transcriptomics and metabolomics were employed to investigate the differences between healthy leaves and infected leaves at three disease stages. In total, 79 alkaloid metabolites were identified, with 30 differential metabolites shared across all infection stages. Transcriptome sequencing revealed 846 differentially expressed genes, many of which were enriched in the isoquinoline alkaloid biosynthesis pathway. Key structural genes (e.g.
TAT
,
PPO
) and transcription factors (e.g.,
WRKY
,
GRAS
) were significantly upregulated during infection, correlating with altered alkaloid profiles. Notably, dopamine, a key intermediate, was downregulated, suggesting a potential shift in metabolic flux toward downstream defense-related alkaloid synthesis. qRT-PCR validation confirmed the expression patterns of selected DEGs. Our findings provide the first comprehensive evidence that alkaloid metabolism, particularly the isoquinoline alkaloid pathway, are transcriptionally and metabolically reprogrammed during blister blight infection, suggesting a potential role in tea’s defense against this pathogen. These results offer valuable insights for breeding resistant tea cultivars.
BACKGROUND
Natural plant metabolites, such as flavonoids and lignin, exhibited safe and environmentally friendly roles in defending against pathogen attack. However, their functional roles in the interaction between wheat and Puccinia triticina (Pt) remained poorly characterized.
RESULTS
In this study, we integrated transcriptomic and quasi-targeted metabolomic analyses to systematically characterize differentially expressed genes (DEGs) and metabolites associated with the compatible and incompatible interactions between wheat and Pt. In the wheat-Pt interaction system, a total of 1,242 metabolites were identified, predominantly classified into amino acids and derivatives, flavonoids, and related compound classes. In the flavonoid and lignin biosynthesis-related pathways-namely, Flavonoid biosynthesis and Phenylpropanoid biosynthesis-significant differences were observed in both the accumulation levels of key metabolites and the expression of genes associated with their biosynthetic pathways. Notably, in the incompatible interaction, the expression of TaCAD, a gene implicated in syringyl lignin (S-lignin) biosynthesis, was significantly up-regulated. Gene regulatory network (GRN) analysis further suggested that transcription factors (TFs) including ERF, LBD, BBR-BPC, and C2H2 may play critical regulatory roles in mediating wheat resistance to leaf rust. Moreover, the key flavonoid hesperetin was markedly enriched in the incompatible combination (TcLr24_120 h vs. TcLr24_0 h). Exogenous application of hesperetin significantly inhibited urediniospores germination in vitro. More importantly, it significantly reduced disease severity of wheat leaf rust in vivo.
CONCLUSIONS
These findings indicated that hesperetin may serve as a potential defense compound in wheat during the early stages of leaf rust infection, providing crucial insights for developing novel natural products and a theoretical foundation for genetic improvement in disease-resistant wheat breeding.
Yaqiong Zhao, Weiwei Gong, Ruimin Wang et al.· BMC Genomics· 0 citations
The combined transcriptome and metabolome analysis revealed that plant hormone signal transduction, phenylpropanoid biosynthesis, and flavonoid biosynthesis were significantly enriched in resistant rice varieties, providing valuable information on the molecular mechanisms by which rice defends against U. virens infection.
Rongtao Fu, Huan Li, Xi Luo et al.· BMC Plant Biology· 0 citations
Tobacco is a model plant as well as an important economic crop. Black shank disease, caused by Phytophthora nicotianae, severely undermines tobacco yield and quality, yet the molecular basis of differential cultivar resistance remains incompletely understood. Here, we compared the resistant cultivar, 'Xiangyan 7' (X7) and the susceptible cultivar 'Honghuadajinyuan' (HD), after inoculation with P. nicotianae race 0. Disease evaluation showed that X7 had a significantly lower disease index than HD. Transcriptomic and metabolomic analyses were performed on leaves collected at 0, 1, 2, 4, 8, and 12 days post-inoculation (dpi). RNA-seq identified extensive transcriptional responses in both cultivars; the inter-cultivar differentially expressed gene (DEG) number peaked at 8 dpi with 14,160 DEGs (7057 up-regulated and 7103 down-regulated). Widely targeted metabolomics detected 1092 metabolites, and the inter-cultivar differentially accumulated metabolite (DAM) number peaked at 12 dpi with 355 DAMs (95 up-regulated and 260 down-regulated). Weighted Gene Co-expression Network Analysis (WGCNA) identified 593 hub genes from three resistance-associated modules (Coral3, Lightblue3, and Lavender). Integrated Kyoto Encyclopedia of Genes and Genomes (KEGG) co-enrichment analysis revealed that phenylpropanoid biosynthesis, biosynthesis of secondary metabolites, and plant hormone signal transduction were common transcriptional-metabolic pathways enriched in X7, together with early calcium-related signaling in the plant-pathogen interaction pathway. These results suggest that the stronger resistance to P. nicotianae by X7 is associated with rapid coordination of defense-related transcription, phenylpropanoid and flavonoid metabolism, hormone signaling, and suppression of photosynthesis and primary metabolism. Our study provides multi-omics resources and candidate genes, including Nitab4.5_0000101g0110, Nitab4.5_0000101g0120, Nitab4.5_0001915g0140, and Nitab4.5_0002942g0040, for improving tobacco resistance to black shank disease.
Guo Li, Changjiang Zhang, Bei Yu et al.· Plant physiology and biochem...· 0 citations
Background/Objectives: This study aims to reveal the physiological and molecular regulatory mechanisms of the genuine medicinal herb I. suzhouensis K. F. Zhai, Z. B. Han & S. B. Zhou (Wangzaozi) of Anhui province in response to drought stress, and clarify the regulatory patterns of drought adversity on the accumulation of its medicinal active ingredients. Methods: Mild natural drought treatment was applied to I. suzhouensis. Combined with Illumina high-throughput transcriptome sequencing and HPLC-MS/MS targeted metabolomics detection, this study jointly deciphered the dynamic changes in gene expression and metabolite accumulation of I. suzhouensis under drought. Key drought-responsive metabolic pathways, core regulatory genes and marker metabolites were screened. Results: A total of 56,823 high-quality unigenes were obtained via transcriptome sequencing, among which 23,580 differentially expressed genes (DEGs) were identified. Functional enrichment analysis revealed that DEGs were predominantly enriched in pathways, including plant hormone signal transduction, phenylpropanoid biosynthesis, flavonoid biosynthesis and photosynthesis. A total of 4171 metabolites were qualitatively and quantitatively characterized via metabolomics, and 1632 differentially expressed metabolites (DEMs) were screened, mainly enriched in phenylpropanoid biosynthesis, tyrosine metabolism, flavone and flavonol biosynthesis pathways. Physiological measurements of antioxidant indices demonstrated that the activities of SOD and POD increased by approximately 2-fold, while PAL activity rose by 1.55-fold, and chlorophyll content decreased significantly. Multi-omics joint analysis indicated that mild drought stress modulates the expression of genes involved in phenylpropanoid, flavonoid and diterpenoid biosynthetic pathways, alters antioxidant enzyme activities, and coordinately regulates the formation of drought tolerance and the accumulation of bioactive compounds in I. suzhouensis. Conclusions: This study systematically elucidates the drought response mechanism of I. suzhouensis cultivated in northern Anhui province. It provides theoretical evidence and candidate core responsive gene resources for standardized cultivation of I. suzhouensis and precise regulation of medicinal quality in drought-prone production areas.
The results suggest that the flavonoid biosynthesis pathway in potatoes plays a key role in responding to PVS infection and promotes the selection and utilization of disease-resistant varieties.
Kuo Wu, Xia Liu, Yu Li et al.· Frontiers in Microbiology· 0 citations