苹果CONSTANS-Like基因家族鉴定及其在盐碱胁迫下的表达分析

Identification of CONSTANS-Like(COL) Gene Family in Malus domestica and Expression Profiling under Saline-Alkali Stress

摘要:

为了解CONSTANS-Like (COL)基因家族的生物学信息、盐碱胁迫下的基因表达及其功能，鉴定并分析了苹果COL转录因子家族的生物学信息、盐碱胁迫下的基因表达及其功能。利用氨基酸特异序列在苹果基因组中检索及转录组数据分析，鉴定出17个苹果COL基因家族成员，并对其做了进一步分析。这17个MdCOL含有329~485个氨基酸，分子量为36 529.03~52 841.95 Da，等电点为5.14~8.11，仅MdCOL10为碱性蛋白，脂肪系数为55.28~72.61，不稳定系数为36.32~58.27，仅Md-COL16为稳定蛋白，均为亲水蛋白，主要定位于细胞核、叶绿体、细胞质和内质网中。有10对同源基因存在基因复制事件，其中，1对同源基因的复制事件可能发生在单-双子叶植物分化时期，7对同源基因的复制事件可能发生在多倍体重复之后，2对同源基因的复制事件可能发生在比200.42 Ma更早的时间。在受到盐碱胁迫后，7个基因的表达模式呈先上升后下降趋势，3个基因的表达模式呈上升趋势；7个基因在叶片和新根中的表达模式不一致。MdCOL转录因子在苹果对光调控、胁迫和植物激素响应、昼夜节律调控、胚乳表达及开花结果等生长发育中发挥重要作用。

Abstract:

Biological characteristics, expression patterns and functional roles of CONSTANS-Like(COL) geneencoded transcription factors under saline-alkali stress were characterized in Malus domestica. A total of 17 MdCOL family genes were identified via conserved amino acid motif screening against the apple whole-genome database combined with transcriptomic data, followed by systematic bioinformatic analysis of these genes. The 17 proteins encoded by MdCOL genes consist of 329-485 amino acids, with molecular weights ranging from 36 529.03 Da to 52 841.95 Da and isoelectric points varying between 5.14 and 8.11. Only the protein encoded by MdCOL10 is classified as an alkaline protein. The aliphatic indexes of all proteins range from 55.28 to 72.61, while their instability coefficients fall within 36.32-58.27; only the protein product of MdCOL16 is predicted as a stable protein, and all MdCOL proteins are judged to be hydrophilic. Subcellular localization prediction indicates that these proteins are mainly distributed in the nucleus, chloroplast, cytoplasm and endoplasmic reticulum. Ten pairs of homologous MdCOL genes are found to have undergone gene duplication events. The duplication event of one homologous gene pair is speculated to occur before the divergence of monocots and dicots, seven pairs are generated after polyploidization events, and the remaining two pairs originate from duplication events dated earlier than 200.42 Ma. Under saline-alkali stress treatments, seven MdCOL genes exhibit expression patterns that rise first and then decline, and three MdCOL genes show continuous upregulation. Discrepant expression trends of seven MdCOL genes are detected between leaf and new root tissues. It is concluded that MdCOL transcription factors exert vital regulatory functions in multiple growth and developmental processes of apple, such as light signal modulation, abiotic stress response, phytohormone signaling, circadian rhythm control, endosperm development, and flowering and fruiting regulation.