| exobasidium vexans infection of camellia sinensis increased 2,3-cis isomerisation and gallate esterification of proanthocyanidins. | infection of leaves of tea (camellia sinensis (kuntze) l, cv tri 2025) which was susceptible to blister blight (exobasidium vexans massee), resulted in a shift of the proanthocyanidin stereochemistry away from 2,3-trans (e.g. catechin and gallocatechin) and towards 2,3-cis (e.g. epicatechin and epigallocatechin). infection also resulted in increased gallic acid esterification of the initiating subunits of proanthocyanidins. this was shown by both mass spectroscopy and phloroglucinolysis. proanth ... | 2004 | 15504433 |
| preformed and induced chemical resistance of tea leaf against exobasidium vexans infection. | levels of (-)-epicatechin in tea cultivars resistant to blister blight leaf disease were significantly higher than those in susceptible cultivars, while the reverse was true for (-)-epigallocatechin gallate, suggesting that epicatechin was involved in the resistance mechanism. the content of the methylxanthines, caffeine and theobromine, in the leaf increased in the initial translucent stage of the disease, probably as a defense response to fungal attack. epicatechin and epigallocatechin levels ... | 2005 | 16222773 |
| serological detection and immunogold localization of cross-reactive antigens shared by camellia sinensis and exobasidium vexans. | pathogenicity of exobasidium vexans, causal agent of blister blight of tea, was studied in 30 commercially cultivated tea varieties by analysing the antigenic patterns of host and pathogen using immunological techniques. | 2007 | 17953578 |
| separation of proanthocyanidins isolated from tea leaves using high-speed counter-current chromatography. | the proanthocyanidin extract from tea (camellia sinensis) leaves was purified for the further study of the biological role of proanthocyanidins in blister blight leaf disease of tea, which is caused by the fungus exobasidium vexans. an aqueous acetone extract of proanthocyanidins prepared from healthy tea leaves was partially purified using sephadex lh-20 chromatography. the crude proanthocyanidin extract obtained was fractionated with high-speed counter-current chromatography (hsccc) using the ... | 2009 | 19136115 |