RESUMO
Tea (Camellia sinensis L.) is a thermophilic evergreen woody plant that has poor cold tolerance. The SAD gene plays a key role in regulating fatty acid synthesis and membrane lipid fluidity in response to temperature change. In this study, full-length SAD cDNA was cloned from tea leaves using rapid amplification of cDNA ends and polymerase chain reaction (PCR)-based methods. Sequence analysis demonstrated that CsSAD had a high similarity to other corresponding cDNAs. At 25°C, the CsSAD transcriptional level was highest in the leaf and lowest in the stem, but there was no obvious difference between the root and stem organs. CsSAD expression was investigated by reverse transcription-PCR, which showed that CsSAD was upregulated at 4° and -5°C. At 25°C, CsSAD was induced by polyethylene glycol, abscisic acid, and wounding, and a similar trend was observed at 4°C, but the mean expression level at 4°C was lower than that at 25°C. Under natural cold acclimation, the 'CsCr05' variety's CsSAD expression level increased before decreasing. The CsSAD expression level in variety 'CsCr06' showed no obvious change at first, but rapidly increased to a maximum when the temperature was very low. Our study demonstrates that CsSAD is upregulated in response to different abiotic conditions, and that it is important to study the stress resistance of the tea plant, particularly in response to low temperature, drought, and wounding.
Assuntos
Adaptação Fisiológica , Camellia sinensis/enzimologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Estearoil-CoA Dessaturase/genética , Sequência de Aminoácidos , Camellia sinensis/genética , Camellia sinensis/fisiologia , Clonagem Molecular , Temperatura Baixa , Secas , Dados de Sequência Molecular , Filogenia , Componentes Aéreos da Planta/enzimologia , Componentes Aéreos da Planta/fisiologia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/enzimologia , Raízes de Plantas/fisiologia , Alinhamento de Sequência , Estearoil-CoA Dessaturase/química , Estearoil-CoA Dessaturase/metabolismoRESUMO
B7 homolog 1 (B7-H1), which is also known as programmed death-L1, is an important member of the B7/CD28 costimulatory factor superfamily, which are emerging as important mediators of various host immune responses. B7-H1 is differentially expressed in various cell subsets and to different extents in human and murine cells. Human B7-H1 is constitutively expressed at low levels in dendritic cells and activated T cells (compared with high expression in activated murine T cells) and is highly expressed in monocytes and tumor cells. We conducted a meta-analysis to explore the association between B7-H1 expression and bladder cancer risk. Two groups were examined, including 352 bladder cancer cases and 60 healthy controls. Meta-analysis results revealed that B7-H1 expression is positively associated with bladder cancer and is strongly associated with the clinical stage of bladder cancer. However, no significant difference was found with respect to gender and the pathological grade of bladder cancer.