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光合系统Ⅰ亚基O(PhotosystemⅠsubunit O,Psa O)是光合系统Ⅰ中的蛋白亚基,在两个光合系统之间平衡激发能方面起着重要的作用.为研究Psa O基因的结构和功能,对甘蔗(Saccharum offi cinarum L.)叶片全长c DNA文库进行测序,获得光合系统Ⅰ亚基O基因的全长c DNA序列,命名为Sc Psa O(Gen Bank Accession Number:KF714498).生物信息学分析表明,该基因全长708 bp,开放阅读框435 bp,编码144个氨基酸;该基因所编码的蛋白定位于叶绿体基质,无信号肽,为疏水性非分泌碱性蛋白,二级结构多为无规则卷曲,含有PJN00046家族的保守结构域,参与能量新陈代谢及脂肪酸新陈代谢.同时,该基因在不同物种间具有较强的保守性,其中与同属C4植物的同源性较C3植物高.荧光定量PCR分析结果表明,甘蔗Sc Psa O基因在叶片中的相对表达量最高,具有一定的组织特异性;在氯化钠(Na Cl)、聚乙二醇(PEG)、氯化铜(Cu Cl2)、脱落酸(ABA)、水杨酸(SA)和茉莉酸甲酯(Me JA)等外源胁迫下,其表达量均呈下调趋势,且以PEG胁迫下的下调表现最为明显.这些结果表明这几种外源胁迫可能抑制甘蔗Sc Psa O基因的转录水平表达,为其进一步功能验证以及在甘蔗基因工程中的应用积累了基础资料.
PhotosystemⅠsubunit O (Psa O), a protein subunit in photosystem I, plays an important role in the balance of excitation energy between the two photosynthetic systems.In order to study the structure and function of Psa O gene, The full-length c DNA sequence of the subunit O gene of photosystem I was obtained by sequencing the full-length cDNA library of leaves of Saccharum offi cinarum L. It was named Sc Psa O (Gen Bank Accession Number: KF714498) The full length of the gene was 708 bp and contained an open reading frame of 435 bp encoding a protein of 144 amino acids. The protein encoded by this gene was located in the chloroplast matrix with no signal peptide, which was a hydrophobic non-secreted basic protein with secondary structure Random curl, containing the conserved domain of PJN00046 family, involved in energy metabolism and fatty acid metabolism, while the gene is highly conserved among different species, of which the homology with C4 plants is higher than that of C3 plants. PCR analysis showed that Sc psa O gene in sugarcane had the highest relative expression level in leaves and had certain tissue specificity. In the presence of sodium chloride (Na Cl), polyethylene glycol (PEG), copper chloride (Cu Cl2) , Abscisic acid (AB A), SA and Me JA showed a downward trend, and the most significant decrease was under PEG stress. Source-stress may inhibit the transcriptional expression of Sc Psa O gene in sugarcane and provide basic information for its further functional verification and its application in genetic engineering of sugarcane.