Catechins are the major active compounds present in the tea plant (Camellia sinensis), the main industrial crop cultivated worldwide.
Tea catechins are produced following the flavonoid metabolic pathways, regulated by multiple enzymes and transcription factors. Image credit: Li et al., doi: 10.1093/hr/uhae178.
Catechins are renowned for their protective effects against conditions like diabetes, cancer, and cardiovascular diseases.
However, their biosynthesis is highly sensitive to environmental factors, particularly phosphate availability, which is often scarce in the soils where tea is grown.
This deficiency can adversely affect tea quality by disrupting the accumulation of secondary metabolites.
Given these challenges, there is an urgent need to understand the molecular mechanisms governing catechin production under varying nutrient conditions.
In the research, Dr. Gaojie Hong from the Institute of Virology and Biotechnology at the Zhejiang Academy of Agricultural Sciences and colleagues explored the complex interplay between phosphate signaling and jasmonate pathways in tea plants.
They identified two key transcription factors, CsPHR1 and CsPHR2, involved in phosphate signaling, and CsJAZ3, a repressor in the jasmonate pathway.
Together, these elements regulate catechin biosynthesis in response to nutrient levels and hormonal signals, providing new insights into the genetic control of tea quality.
The researchers demonstrated that phosphate deficiency activates critical genes in catechin biosynthesis through CsPHR1 and CsPHR2, boosting the expression of CsANR1 and CsMYB5c, which are pivotal in catechin production.
Additionally, CsSPX1, a phosphate pathway repressor, was found to inhibit the action of CsPHR1 and CsPHR2, fine-tuning the response to phosphate availability.
The scientists further revealed that CsJAZ3 interacts with CsPHR1 and CsPHR2, linking jasmonate signaling with phosphate regulation.
This interaction is essential for balancing the plant’s adaptive response to nutrient stress and hormonal changes, thereby influencing catechin content and overall tea quality.
“Our study unveils a complex regulatory network where phosphate and jasmonate pathways intersect to control catechin biosynthesis in tea plants,” Dr. Hong said.
“These insights not only deepen our understanding of tea metabolism but also offer potential strategies for enhancing tea quality through precise genetic and environmental management.”
The study was published in the journal Horticulture Research.
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Linying Li et al. 2024. CsPHRs-CsJAZ3 incorporates phosphate signaling and jasmonate pathway to regulate catechin biosynthesis in Camellia sinensis. Horticulture Research 11 (8): uhae178; doi: 10.1093/hr/uhae178
