Tea’s molecular shield against anthracnose
image: Proposed model for JA-mediated SAK-dependent anthracnose resistance. Upon C. camelliae infection, pathogen attack triggers differential JA signaling responses between tea cultivars. In the resistant cultivar Zijuan (ZJ), enhanced JA accumulation leads to stronger activation of the transcription factor CsMYC2.1, which directly binds to the CsNOMT promoter and activates its expression. Elevated CsNOMT expression drives increased SAK biosynthesis through the methylation of naringenin. The accumulated SAK acts as a potent phytoalexin, providing enhanced antifungal activity against anthracnose pathogens and contributing to the disease-resistant phenotype. In contrast, the susceptible cultivar Longjing 43 (LJ43) exhibits weaker JA signaling, resulting in lower CsMYC2.1 activation, reduced CsNOMT expression, minimal SAK accumulation, and consequently increased susceptibility to anthracnose infection. This model illustrates how cultivar-specific differences in JA signaling efficiency determine the strength of the CsMYC2.1–CsNOMT–SAK defense axis, ultimately controlling disease resistance outcomes in tea plants.
Credit: Horticulture Research
Anthracnose is one of the most destructive diseases affecting tea, threatening yield, leaf quality, and the sustainability of tea production. A new study reveals how resistant tea plants activate a natural chemical defense after pathogen attack. By comparing the anthracnose-resistant tea cultivar ‘Zijuan’ with the susceptible cultivar ‘Longjing43’, researchers identified sakuranetin (SAK) as a pathogen-induced antifungal compound in tea. They further traced its production to a jasmonic acid (JA)-responsive pathway controlled by the transcription factor CsMYC2.1 and the biosynthetic gene CsNOMT. The study uncovers an inducible immune mechanism in tea and offers molecular targets for breeding disease-resistant cultivars with reduced reliance on synthetic fungicides.
Tea (Camellia sinensis) is one of the world’s most widely consumed beverages and an economically important perennial crop. However, anthracnose caused by Colletotrichum camelliae (C. camelliae) can spread through wind and rain, establish latent infections, and cause serious field losses. Disease control still depends largely on synthetic fungicides, raising concerns about environmental pressure and chemical residues in a crop consumed as direct infusions. Although tea is rich in defensive metabolites, previous studies have mainly focused on constitutive compounds such as catechins and caffeine. Due to these challenges, in-depth research is needed into inducible immune mechanisms activated by tea plants after pathogen infection.
Researchers from the Zhejiang Academy of Agricultural Sciences published (DOI: 10.1093/hr/uhag022) the study in Horticulture Research on 29 January 2026. The research was conducted by teams from the State Key Laboratory for Quality and Safety of Agro-Products, the Institute of Virology and Biotechnology, and the Institute of Sericulture and Tea. Using integrated transcriptomic, metabolomic, biochemical, and functional analyses, the team investigated why ‘Zijuan’ shows stronger resistance to anthracnose than ‘Longjing43’ and identified a JA–CsMYC2.1–CsNOMT–sakuranetin (SAK) module that drives cultivar-specific defense.
The study first showed clear disease differences between the two tea cultivars: ‘Zijuan’ restricted lesion development and fungal accumulation, whereas ‘Longjing43’ allowed broader pathogen spread. Multi-omics analysis revealed stronger activation of JA signaling and flavonoid-related metabolism in the resistant cultivar. Among several caffeic acid O-methyltransferase (COMT)-like genes, CsNOMT was identified as encoding naringenin 7-O-methyltransferase (NOMT), the enzyme responsible for converting naringenin into SAK. Liquid chromatography–mass spectrometry (LC–MS) confirmed that SAK accumulated strongly in infected ‘Zijuan’ leaves but remained low in ‘Longjing43’. In antifungal assays, SAK suppressed C. camelliae more effectively than epigallocatechin gallate (EGCG), a major tea catechin. Functional validation strengthened the conclusion: silencing CsNOMT reduced SAK accumulation and increased disease susceptibility, while overexpressing CsNOMT raised SAK levels and reduced lesion formation. Further assays showed that CsMYC2.1 directly binds the CsNOMT promoter and activates its expression under JA signaling.
The authors said the findings show that tea anthracnose resistance is not simply a matter of possessing a resistance-related gene, but of how strongly and rapidly the plant activates its defense network. They said the JA-responsive CsMYC2.1–CsNOMT module works as a molecular relay: pathogen infection stimulates JA signaling, CsMYC2.1 activates CsNOMT, and CsNOMT drives SAK production. This inducible response gives resistant tea plants a timely chemical barrier against fungal invasion and helps explain why some cultivars are naturally better protected than others.
The discovery provides practical tools for sustainable tea production. CsNOMT and CsMYC2.1 could serve as functional markers for screening anthracnose-resistant germplasm and accelerating marker-assisted breeding. Because SAK showed strong antifungal activity, it may also guide the development of natural biopesticides or defense-priming strategies that reduce chemical fungicide use. More broadly, the work demonstrates that inducible phytoalexin-mediated immunity, previously well characterized in model plants and rice, also plays an important role in woody perennial crops. By linking hormone signaling, transcriptional regulation, metabolite biosynthesis, and disease resistance, this study offers a clearer molecular framework for building resilient, high-quality tea cultivars.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhag022
Funding information
This research was supported by the Zhejiang Provincial Natural Science Foundation (grant LY24C160004), the Natural Science Foundation of China (grants 32470267 and 32272553), the Major Science and Technology Special Project of Variety Breeding of Zhejiang Province (2021C02067-7).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.