Camellia sinensis
var.sinensisis widely grown for tea beverages that possess significant health promoting effects. Studies on tea plant genetics and breeding are hindered due to its recalcitrance toAgrobacterium-mediated genetic transformation. Among the possible reasons, oxidation of phenolics released from explant tissues and bactericidal effects of tea polyphenols during the process of transformation play a role in the plant recalcitrance. The aim of the present study was to alleviate the harmful effects of phenolic compounds usingin-plantatransformation.
Two-month old seedlings of tea cultivar "Nong Kangzao" were infected at the hypocotyl with wild typeAgrobacterium rhizogenesand maintained in an environment of high humidity. 88.3% of infected plants developed hairy roots at the wounded site after 2 months of infection. Our data indicated that transgenic hairy root induction of tea can be achieved usingA. rhizogenesfollowing the optimized protocol.
With this method, composite tea plants containing wild-type shoots with transgenic roots can be generated for "in root" gene functional characterization and root-shoot interaction studies. Moreover, this method can be applied to improve the root system of composite tea plants for a better resistance to abiotic and biotic stresses.