Combined foliar application of CLE25 and EGCG enhances drought resilience and recovery in tea plants

• Under DS sugars rose while RWC, pigments, and proteins declined; EGCG+CLE25 treatment restored them. • ABA and SA levels rose under DS, with ABA further increasing post-rewatering. • Catechins, especially EGCG, decreased under DS but were restored with EGCG+CLE25. • Total AAs rose under DS but declined post-recovery, moderated by EGCG+CLE25, notably proline. • EGCG+CLE25 treatment altered expression of key ABA and JA pathway genes (CsNCED, CsPYL8, CsABF, CsJAZ). Drought stress (DS) is a major constraint on tea plant productivity and quality. Although foliar application of epigallocatechin gallate (EGCG) and the signal peptide CLE25 confers drought resistance, the underlying mechanisms remain poorly defined and require further elucidation. This study investigates their combination effects through phenotypic, biochemical, and genetic analyses under DS. Drought caused leaf wilting, reduced relative water content (RWC), pigments, and soluble proteins, while increasing sugars and amino acids, but the CLE25+EGCG treatment alleviated these symptoms and improved recovery after rewatering. DS severely reduced EGCG content from 24.9 to15.7mg·g⁻¹, foliar treatment with CLE25+EGCG fully restored it. ABA and SA levels increased under DS, with ABA levels rising further after rewatering. Key ABA pathway genes ( CsNCED, CsPYL8, CsABF ) and stress-responsive genes ( P5CS, HSP, CsPOX ) were modulated by CLE25+EGCG, alongside jasmonic acid-related genes ( CsJAZ, CsMYC2 ). Integrated analysis of gene expression and metabolite profiles elucidated the drought resistance mechanisms in tea plants, highlighting CLE25+EGCG foliar application as an effective strategy to enhance drought tolerance.