Response of Tea Plants to Water Stress

Two-year-old potted plants of six Camellia sinensis cultivars (TV-18, TV-26, UPASI-3, UPASI-26, T-78 and HV-39) were subjected to water stress for 4, 8 and 12 d. Relative water content (RWC) of leaves of all cultivars declined with water stress, but in the two drought tolerant cultivars (UPASI-3 and UPASI-26), higher RWC were maintained in comparison to the others. Phenol content and activities of phenylalanineammonialyase, polyphenoloxidase and peroxidase initially increased, but decreased during extended drought. Chlorophyll contents decreased, whereas proline contents increased during water stress. SDS-PAGE analysis of proteins revealed increased accumulation of proteins of intermediate molecular masses (42 - 44 kDa) and low molecular masses (14 - 26 kDa). After 12 d of water stress, most of these proteins disappeared in T-78 and HV-39, but in the other cultivars they were still detectable.