毛竹捕光色素结合蛋白基因结构及表达模式分析

Structure and Expression Analysis of Light-harvesting Chlorophyll a/b Binding Protein Genes in Moso Bamboo(Phyllostachys edulis)

植物通过光合作用将光能转换为化学能,捕光色素结合（LHC）蛋白与色素形成的复合体在捕获、传递和转化光能过程中发挥着重要作用,因此研究毛竹（Phyllostachys edulis）LHC基因结构及表达模式对于揭示其在毛竹光合作用中的功能具有重要意义。采用生物信息学的方法,对毛竹基因组中的LHC基因进行了系统分析。结果表明,在毛竹中共有29个LHC基因同源序列,其包含的内含子数量为0~5个。序列分析表明,29个LHC基因编码的蛋白分别属于光系统Ⅰ和光系统Ⅱ的捕光色素结合蛋白家族LHCⅠ和LHCⅡ。LHCⅠ包含5个亚家族（Lhca 1-Lhca 5）,除了Lhca 4含有3个成员外其他亚家族只有1个成员;而LHCⅡ包含6个亚族（Lhcb 1-Lhcb6）,每个亚家族的成员不同,其中Lhcb 1的成员最多为7个。亲疏水性预测表明,不同亚家族成员存在着一定差异。蛋白结构预测发现,29个蛋白均包含导肽和成熟蛋白,具有跨膜结构域,均包含色素结合位点;其中12个蛋白的组成以α-螺旋为主,17个蛋白的组成以随机卷曲为主。基因表达谱分析表明,大多数LHC基因主要在叶片和花序中表达,笋中略有表达,而根和鞭中几乎检测不到表达。研究结果为进一步研究毛竹LHC基因的功能奠定了基础。

Plants convert the solar energy into chemical energy through photosynthesis, and the light-harvesting chloro- phyll a/b binding （LHC） protein plays a crucial role in the process of energy capture, transfer and conversion. There- fore, the study on the structure and expression pattern of LHC genes is of great significance to reveal their functions in photosynthesis of moso bamboo （Phyllostachys edulis） . A genome-wide analysis of carried out using bioinformatics methods. The resuhs showed that there were 29 LHC LHC genes in moso bamboo was homologous genes in moso barn- boo, of which the intron numbers ranged from 0 to 5. On the basis of sequence analysis, the proteins encoded by 29 LHC genes belonged to LHC I in PSI and LHC II in PS II respectively. LHC I contained 5 subfamilies （Lhcal- Lhca5 ）, each of which only had one member except Lhca 4 with 3 members, while LHC II contained 6 subfamilies （Lhcbl-Lhcbr） which have a varied range of members each, among which Lhcbl subfamily had a maximum of seven members. Hydrophilic and hydrophobic prediction demonstrated that there was a certain difference in the members of different subfamilies. The results of protein structure prediction showed that all the 29 proteins encoded by LHC genes was composed of transit peptide and mature protein, which contained transmembrane structure and pigment binding sites. There were 12 proteins predicted with priority ofalpha helix and 17 proteins with priority of random curl. The a- nalysis of gene expression profile suggested that most of LHC genes mainly express in leaves and panicles, and few in shoot, but almost undetectable in rhizome and root. Overall, these results laid a significant foundation for further study on the LHC gene function in moso bamboo.