RESUMEN
Volatile terpenoids produced in tea plants (Camellia sinensis) are airborne signals interacting against other ecosystem members, but also pleasant odorants of tea products. Transcription regulation (including transcript processing) is pivotal for plant volatile terpenoid production. In this study, a terpene synthase gene CsLIS/NES was recovered from tea plants (C. sinensis cv. "Long-Men Xiang"). CsLIS/NES transcription regulation resulted in 2 splicing forms: CsLIS/NES-1 and CsLIS/NES-2 lacking a 305 bp-fragment at N-terminus, both producing (E)-nerolidol and linalool in vitro. Transgenic tobacco studies and a gene-specific antisense oligo-deoxynucleotide suppression applied in tea leaves indicated that CsLIS/NES-1, localized in chloroplasts, acted as linalool synthase, whereas CsLIS/NES-2 localized in cytosol, functioned as a potential nerolidol synthase, but not linalool synthase. Expression patterns of the 2 transcript isoforms in tea were distinctly different and responded differentially to the application of stress signal molecule methyl jasmonate. Leaf expression of CsLIS/NES-1, but not CsLIS/NES-2, was significantly induced by methyl jasmonate. Our data indicated that distinct transcript splicing regulation patterns, together with subcellular compartmentation of CsLIS/NE-1 and CsLIS/NE-2 implemented the linalool biosynthesis regulation in tea plants in responding to endogenous and exogenous regulatory factors.
Asunto(s)
Camellia sinensis/genética , Monoterpenos/metabolismo , Proteínas de Plantas/metabolismo , Empalme del ARN/genética , Acetatos/farmacología , Monoterpenos Acíclicos , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/metabolismo , Secuencia de Bases , Camellia sinensis/efectos de los fármacos , Camellia sinensis/metabolismo , Ciclopentanos/farmacología , Flores/efectos de los fármacos , Flores/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Oxilipinas/farmacología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Empalme del ARN/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sesquiterpenos/metabolismo , Fracciones Subcelulares/metabolismo , Terpenos/metabolismo , Nicotiana/genéticaRESUMEN
In this paper, the determination of Ba using oxygen enriched air-acetylene flame in AAS has been studied and the effect of acetylene flow, oxygen flow and the ratio of O2/C2H2 on the absorbance have been compared. When the amount of oxygen is 52% in mixed gas and the ratio of O2/C2H2 is about 0.72, higher sensitivity for Ba can be obtained. In this flame acids and most of elements did not interfere. By adding 1,000 mg.L-1 K the interference can be minimized and the sensitivity for the determination of Ba can be increased. The sensitivity of the method is 0.16 mg.L-1/1%, the detection limit is 0.034 mg.L-1, and the relative standard deviation is 2.5%. The analytical results of the standard reference material (GBW08301 and GSD-6) by this method are consistent with the certified values, and it was proved that this method are reliable and is suitable for the determination of Ba in mineral water.