Tea trichomes containspecial flavor-determining metabolites; however,little is known about how and why tea trichomes produce them. Integratedmetabolite and transcriptome profiling on tea trichomes in comparisonwith that on leaves showed that trichomes contribute to tea plantdefense and tea flavor and nutritional quality. These unicellular,nonglandular, and unbranched tea trichomes produce a wide array oftea characteristic metabolites, such as UV-protective flavonoids,insect-toxic caffeine, herbivore-defensive volatiles, and theanine,as evidenced by the expression of whole sets of genes involved indifferent metabolic pathways. Both dry and fresh trichomes containseveral volatiles and flavonols that were not found or at much lowlevels in trichome-removed leaves, including benzoic acid derivatives,lipid oxidation derivatives, and monoterpene derivatives. Trichomesalso specifically expressed many disease signaling genes and variousantiherbivore or antiabiotic peptides. Trichomes are one of the domesticationtraits in tea plants. Tea trichomes contribute to tea plant defensesand tea flavors.
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