Integrative approaches unravelling tea drought alleviation mechanisms primed by carbonyl volatiles and signal peptide.

Drought stress (DS) significantly hampers the growth and productivity of tea plants, necessitating effective strategies to enhance their resilience. This study comprehensively investigated the mechanisms of carbonyl volatiles-methyl jasmonate (MeJA) and cis-3-hexenyl acetate (cis-3-HAC) and signal peptide CLAVATA3/EMBRYO-SURROUNDING REGION-RELATED 25 (CLE25) promotion DS resistance using integrative metabolomics and proteomics strategy. Total pigment content decreased, while soluble sugar and proteins increased significantly under DS and further increased after foliar inducement of CLE25, MeJA, and cis-3-HAC. Gallated catechins and amino acids exhibited apparent decreased under DS, especially EGCG (24.6-13.4 mg g) and theanine (10.66-3.78 mg g), but significantly mitigated by CLE25 inducement. Antioxidant enzymes activity, such as catalase (CAT), jumped from 23.1 to 48.2 and further boosted to 118.8 Ugmin FW with CLE25. Proteomic analysis revealed massive increased in stress tolerance proteins, particularly dehydrins and heat shock proteins, rising by >50.0 % with CLE25 inducement and the expression levels of peroxidase (POX), superoxide dismutase (SOD), α-galactosidase (α-GAL), carboxypeptidases (CPs), and transaldolase (TAL) exhibited higher after inducement. Furthermore, stress signaling-related proteins were in-depth explored, especially thioredoxin proteins; sucrose non-fermenting 1-related protein kinase 2 (SnRK2) was novelly verified in activating abscisic acid (ABA) responding. Differences among drought resistance mechanisms after carbonyl volatile and CLE25 treatments were comprehensively studied. The integration of metabolite and protein levels provided a comprehensive illustration of tea DS tolerance mechanisms and offered promising promotion strategies through foliar application of MeJA, cis-3-HAC, and CLE25.