Temperature‐relied defense: Cs MYBs ‐ Cs HT9 modules activate N ‐feruloylputrescine biosynthesis against anthracnose in tea ( Camellia sinensis )

Tea (Camellia sinensis), a globally significant economic crop, is severely affected by anthracnose disease, impacting both yield and quality. Our previous research identified N-feruloylputrescine (Fer-Put) as enhancing tea's disease resistance, with CsHT9 potentially crucial for Fer-Put biosynthesis. In this investigation, we observed that invasion by the anthracnose pathogen activates the expression of CsMYB175/114 and CsHT9. Through in vivo and in vitro experiments, we discovered that CsHT9 is involved in Fer-Put synthesis and is directly regulated by CsMYB175 and CsMYB114. These MYB transcription factors activate CsHT9 expression, elevate Fer-Put levels, induce reactive oxygen species accumulation, and enhance tea plant resistance to anthracnose. Interestingly, within the optimal temperature range for anthracnose, increased temperature upregulates CsMYB175 expression, enhancing its ability to activate CsHT9 downstream. This study elucidates the CsMYBs-CsHT9-Fer-Put resistance pathway in tea plants, offering insights for environmentally friendly disease control and the development of disease-resistant woody plants such as tea.