甘薯MAPK基因家族的鉴定及生物信息学分析

Genome-Wide Identification and Bioinformatic Analysis of Mitogen Activated Protein Kinase Gene Family in Sweet Potato

丝裂原活化蛋白激酶(MAPK)级联反应在植物生长发育以及生物和非生物胁迫反应中发挥着重要作用。为探明甘薯基因组中MAPK基因结构特征,利用生物信息学方法筛选鉴定出了18个二倍体甘薯(Ipomoeatrifida)MAPK基因家族成员,并分析其基因位置、基因结构、所编码的蛋白质理化性质、保守基序、系统进化和蛋白质互作关系。结果表明:甘薯18个MAPK基因不均匀分布在9条染色体上,所编码的氨基酸数量为365~629,均为亲水蛋白,并且大部分属于酸性蛋白和不稳定蛋白。亚细胞定位预测结果表明,仅有ItfMAPK7、ItfMAPK9和ItfMAPK15三个蛋白位于细胞质中,其余均位于细胞核内。系统进化分析将18个基因分成4个亚组,相同组内成员具有相似的基因结构、外显子数量及motif数量,但亚组之间存在明显的差异,并且发现甘薯的MAPK基因家族成员与拟南芥的亲缘关系最近。进一步分析各个亚组所包含基因的外显子和内含子结构,发现不同的亚组之间ItfMAPK基因的结构存在显著的差异,但亚组之间却十分相似。蛋白质互作分析发现甘薯MAPK基因家族成员既存在组内的两两互作关系,也存在亚组之间的互作关系。ItfMAPKs在7个不同组织中和4种不同非生物胁迫下的表达模式分为两类,大部分MAPK基因家族成员在不同组织中和不同胁迫下的表达量很高,而ItfMAPK6、ItfMAPK10和ItfMAPK12这3个成员的表达量极低。研究结果可为深入探寻甘薯MAPK基因的功能提供参考。

Mitogen-activated protein kinase(MAPK)cascade plays an important role in plant growth and development as well as biotic and abiotic stress responses.In order to analyze the structural characteristics of MAPK gene in sweet potato genome,we identified 18 members of Ipomoea trifida MAPK gene family using bioinformatics methods,and analyzed their location,gene structure,protein physicochemical properties,conserved motifs,phylogenetic evolution and protein interactions.The results showed that 18 MAPK genes of sweet potato were distributed unevenly on 9 chromosomes,and the number of amino acids were 365~629,all of them were hydrophilic proteins,most of them belong to acidic proteins and unstable proteins.Subcellular localization prediction showed that only three proteins,ItfMAPK7,ItfMAPK9 and ItfMAPK15,were located in the cytoplasm,and the rest were located in the nucleus.Phylogenetic analysis divided 18 genes into 4 subgroups,and members in the same group had similar gene structure,exon numbers and motif numbers,but significant differences between subgroups.We found that the MAPK gene family members of sweet potato have the closest genetic relationship with Arabidopsis.Further analysis of the exon and intron structures of the genes contained in each subgroup showed that there were significant differences in the structure of ItfMAPK genes among different subgroups,but the subgroups were very similar.Protein interaction analysis revealed that the MAPK gene family members of sweet potato had not only intergroup but also subgroup interactions.The expression patterns of ItfMAPKs in seven different tissues and four different abiotic stresses were divided into two groups.Most members of MAPK gene family were highly expressed in different tissues and different stresses,while the expression levels of ItfMAPK6,ItfMAPK10 and ItfMAPK12 were extremely low.The results can provide references for further exploring the function of MAPK genes in sweet potato.