Differential display-mediated identification of three drought-responsive expressed sequence tags in tea [Camellia sinensis (L.) O.!Kuntze]

There is no information on drought-modulated gene(s) in tea [Camellia sinensis (L.) O. Kuntze], a woody and perennial plant of commercial importance. Using differential display of mRNA, three drought-modulated expressed sequence tags (ESTs) were identified. Northern and BLAST analysis revealed that clone dr1 (droughtresponsive), induced only by drought but not by ABA, showed significant scores with PR-5 (pathogenesis related) family of PR-protein gene. Another clone dr2, repressed by drought but not by ABA, had nucleotide repeats for polyasparate that are also present in chicken calsequestrin-like mRNA. Clone dr3, responded similarly to clone dr2 but did not show significant homology with the reported genes, hence appears to be novel. Identification of these ESTs is an initial step to clone the full length genes and their promoters.