【摘要】 捕光叶绿素a/b结合蛋白在植物光合进程及非生物胁迫响应中发挥着重要的作用。为了研究陆地棉GhLhcb2A1基因特征、表达特性以及在低温和干旱响应中的功能，以冀棉262叶片cDNA为模板进行PCR扩增，获得了GhLhcb2A1基因的CDS全长，通过生物信息学分析了基因及其编码蛋白的基本特征，利用qRT-PCR技术检测了基因的组织表达特性以及低温和干旱响应表达模式，采用病毒诱导的基因沉默技术验证了GhLhcb2A1基因在低温和干旱响应中的功能。研究结果表明，GhLhcb2A1基因CDS全长为798 bp,编码265个氨基酸。GhLhcb2A1在叶片中高表达，在低温和干旱处理的叶片和根中显著上调表达，并在低温和干旱处理3 h的叶片中达到最大值，分别是对照叶片中的17.42,30.03倍，在低温处理6 h和干旱处理12 h的根中达到最大值，分别是对照根中的11.65,65.04倍。亚细胞定位结果表明，GhLhcb2A1蛋白在细胞叶绿体中表达。GhLhcb2A1基因沉默植株与对照植株相比，低温和干旱处理造成的植株失水干枯等表型更严重，叶片积累的丙二醛含量显著升高，脯氨酸含量和超氧化物歧化酶活性则显著降低，说明GhLhcb2A1基因沉默植株对低温和干旱胁迫的抵抗力降低。以上研究表明，GhLhcb2A1基因在低温和干旱响应中发挥正调控的作用。更多还原

【Abstract】 Light-harvesting chlorophyll a/b binding proteins are important in plant photosynthesis and abiotic stress response.To study the characteristics of GhLhcb2A1 and its expression patterns and functions in low temperature and drought response in upland cotton, full-length CDS of GhLhcb2A1 gene was cloned from the leaf cDNA of Jimian 262 by PCR.Bioinformatic analysis was conducted to learn the basic characteristics of the gene.The expression patterns and functions in low temperature and drought response were evaluated by qRT-PCR and virus-induced gene silencing.It was shown that the length of GhLhcb2A1 CDS was 798 bp, encoding 265 amino acids.GhLhcb2A1 was highly expressed in leaves and was significantly up-regulated in leaves and roots under low temperature and drought treatment.Compared with the control, its expression maximized at 3 h under low temperature and drought in leaves with 17.42 and 30.03 folds increase respectively, whereas maximized at 6 h under low temperature and 12 h under drought in roots with 11.65 and 65.04 folds respectively.Subcellular localization assay verified that GhLhcb2A1 was expressed in the chloroplasts of cells.Compared with the control plants, GhLhcb2A1 silenced plants showed a more severe phenotype of water loss and dryness under both low temperatures and drought.The accumulated malondialdehyde content in the leaves of the silenced plants was significantly higher than that of the control, while the proline content and superoxide dismutase activity were significantly lower than those of the controls, suggesting that GhLhcb2A1 silenced plant reduced the resistance to low temperature and drought.The above results implied that this gene played a positive role in regulating low temperature and drought response.更多还原