A study aimed at identifying putative drought responsive genes that confer tolerance to water stress deficit in tea plants was conducted in a 'rain-out shelter' using potted plants. Eighteen months old drought tolerant and susceptible tea cultivars were each separately exposed to water stress or control conditions of 18 or 34% soil moisture content, respectively, for three months. After the treatment period, leaves were harvested from each treatment for isolation of RNA and cDNA synthesis. The cDNA libraries were sequenced on Roche 454 high-throughput pyrosequencing platform to produce 232,853 reads. After quality control, the reads were assembled into 460 long transcripts (contigs). The annotated contigs showed similarity with proteins in the Arabidopsis thaliana proteome. Heat shock proteins (HSP70), superoxide dismutase (SOD), catalase (cat), peroxidase (PoX), calmodulinelike protein (Cam7) and galactinol synthase (Gols4) droughtrelated genes were shown to be regulated differently in tea plants exposed to water stress. HSP70 and SOD were highly expressed in the drought tolerant cultivar relative to the susceptible cultivar under drought conditions. The genes and pathways identified suggest efficient regulation leading to active adaptation as a basal defense response against water stress deficit by tea. The knowledge generated can be further utilized to better understand molecular mechanisms underlying stress tolerance in tea.

Consumption of beverage tea rich in flavonoids is associated with a wide range of health benefits. However, the industry in Kenya has over-relied on black tea whose sustainability is not guaranteed due to glut in the market resulting in low income to farmers. Product characteristics and prices are determined based on the accumulation of the phenolic compounds that are profoundly influenced by environmental and cultivar differences. Profiles of quality-related components were assessed in six new and existing cultivars over three distinct annual seasons. Weather data indicated the wet-cold (April–August) season received the largest amount of precipitation and highest relative humidity, while the hot-dry season (January to March) was the driest with a lower relative humidity. Total catechin (TC) contents were significantly (P less than or equal to0.05) different among the cultivars, seasons, and interactions season x site and cultivar x season x site. Overall, the purple-leafed cultivars had lower TC content compared to the green-leafed teas, whereas teas obtained during the WW season (September–December) had higher levels (14.3%) that are suitable for processing of high-quality tea products. Esterified catechins, EGCG and ECG, formed the major component among individual catechins studied. EGCG was significantly higher during both the CW and WW seasons. Cultivars of ‘China type’ accumulated higher +C content as compared to the ‘Assam type’. EC was highest during the WW season in Timbilil, while in Kangaita, the CW season had slightly higher content. Generally, the Cambod type cv. TRFK 301/1 had the highest caffeine content, while China type cv. TRFK 73/1 had the lowest content. Unlike catechin, caffeine content was highest during the HD season. This information is crucial for interventions on product diversification, value addition and novel marketing strategies in tea.