The pink ring phenomenon: key to tea plants’ disease resistance discovered

Tea plants, rich in polyphenols, are renowned for their health benefits, but their internal defense mechanisms against fungal diseases like anthracnose remain unclear. Anthracnose, a major threat in warm, humid regions, causes severe crop damage. Given these challenges, researchers sought to explore how phosphate deficiency influences plant immunity, leading to this study.

A team from Anhui Agricultural University published a study (DOI: 10.1093/hr/uhad222) on December 5, 2023, in Horticulture Research. The research reveals how anthracnose-induced phosphate deficiency prompts tea plants to produce anthocyanin-3-O-galactoside, a phytoalexin that inhibits fungal growth. This discovery opens the door to breeding more resistant tea cultivars.

The study focused on how Colletotrichum camelliae infects tea leaves, forming a distinctive “pink ring” rich in anthocyanin-3-O-galactoside around infected areas. Researchers identified key genes like flavanone 3-hydroxylase (CsF3Ha) and anthocyanidin synthase (CsANSa) that drive anthocyanin biosynthesis, which was upregulated by phosphate deficiency caused by the infection. This accumulation of anthocyanins in mesophyll cells effectively restricted fungal spread, highlighting a link between phosphate scarcity and enhanced disease resistance. These findings offer a promising strategy to bolster tea plants’ natural defenses.

Dr. Liping Gao, one of the study’s lead authors, remarked, “This discovery is a milestone in understanding plant immunity under nutrient stress. By adjusting phosphate levels, we can naturally enhance tea plants’ resistance, marking a significant advance in sustainable farming.”

This research holds major implications for agriculture, especially in regions severely impacted by anthracnose. By managing phosphate deficiency, farmers could boost tea plants’ natural defenses without relying on chemicals, offering a sustainable solution to protect crops, reduce losses, and increase yields.

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References

DOI

10.1093/hr/uhad222

Original Source URL

https://doi.org/10.1093/hr/uhad222

Funding information

We thank the Natural Science Foundation of China (U21A20232, 32372756,32072621), the Anhui Provincial Natural Science Foundation (2308085MC94), the National Key Research and Development Program of China (2022YFF1003103), and the Anhui Key Research and Development Program of China (202204c06020035).

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, 2022. 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.