Tea plant defense: new insights into anthracnose resistance mechanisms

In a recent study, researchers identified key genetic factors that enhance tea plant resistance to Colletotrichum gloeosporioides, the pathogen responsible for anthracnose, a devastating disease in tea cultivation. The study revealed how two specific transcription factors, CsNAC17 and CsbHLH62, work together to activate the resistance gene CsRPM1. This gene regulates plant immune responses, triggering a hypersensitive reaction and heightened defense against the pathogen. By understanding these genetic interactions, this research provides new avenues for breeding tea plants with enhanced disease resistance, critical for sustaining tea production in vulnerable regions.

Anthracnose, caused by Colletotrichum gloeosporioides, is a significant threat to tea crops, particularly in humid regions where the disease spreads rapidly. Current disease management relies heavily on chemical treatments, which pose risks to food safety and the environment. Exploring the genetic basis of plant resistance offers a sustainable alternative to chemical solutions. Previous studies suggested the involvement of NAC transcription factors in enhancing resistance, but the exact mechanisms remained unclear. This study sheds light on the role of the CsNAC17 and CsbHLH62 genes, advancing our understanding of tea plant immunity.

A team of researchers from Nanjing Agricultural University published (DOI: 10.1093/hr/uhae295) their findings in Horticulture Research (October 2024), detailing the interaction between two transcription factors, CsNAC17 and CsbHLH62, which significantly enhance tea plant resistance to anthracnose. The study provides compelling evidence that these genetic factors activate the CsRPM1 resistance gene, triggering plant defense mechanisms against fungal pathogens.

Through a series of molecular experiments, including yeast two-hybrid screening, bimolecular fluorescence complementation, and co-immunoprecipitation assays, the team demonstrated that CsNAC17 directly interacts with CsbHLH62, facilitating its binding to the CsRPM1 promoter. This interaction enhances the expression of CsRPM1, which is critical for the plant's hypersensitive response (HR) to infection. Overexpression of these genes in both tobacco and tea plants led to stronger resistance against Colletotrichum gloeosporioides, while silencing these genes compromised the plants' ability to defend against the pathogen. These results emphasize the importance of CsNAC17 and CsbHLH62 in boosting plant immunity.

Dr. Xinghui Li, one of the study's authors, commented: "Our research highlights the potential of leveraging natural plant defenses to combat disease. The interaction between CsNAC17 and CsbHLH62 represents a critical mechanism in tea plants' immune response. These findings not only provide new insights into plant-pathogen interactions but also pave the way for developing disease-resistant tea varieties through genetic modification or breeding."

This discovery has significant implications for agricultural practices, especially for tea production in regions affected by anthracnose. By enhancing the resistance of tea plants to this pathogen, the research could lead to the development of more resilient tea crops, reducing the need for chemical pesticides. Moreover, the insights into genetic regulation can be applied to other crops, offering broader agricultural benefits in combating plant diseases globally.

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References

DOI

10.1093/hr/uhae295

Original Source URL

https://doi.org/10.1093/hr/uhae295

Funding information

This work was supported financially by Key Research and Development Program of Jiangsu (BE2023364), National Key Research and Development Program of China (2022YFD1200505), Science and Technology Projects of Nanjing (202210013), Development of New Products from Summer and Autumn Tea in Wen County (2023), National Natural Science Foundation of China (32172628), Nanjing Agricultural Major Technology Collaborative Promotion Plan Project (2024NJXTTG 10) and Research and Demonstration Project of key technologies of tea garden photovoltaic power generation (HNKJ22- H135).

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.