National Research Center for Apple Engineering and Technology, College of Horticulture Science and Technology, State Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong 271018, PR China.
Gene. 2013 Dec 1;531(2):377-87. doi: 10.1016/j.gene.2013.07.107. Epub 2013 Aug 9.
MAPK signal transduction modules play crucial roles in regulating many biological processes in plants, which are composed of three classes of hierarchically organized protein kinases, namely MAPKKKs, MAPKKs, and MAPKs. Although genome-wide analysis of this family has been carried out in some species, little is known about MAPK and MAPKK genes in apple (Malus domestica). In this study, a total of 26 putative apple MAPK genes (MdMPKs) and 9 putative apple MAPKK genes (MdMKKs) have been identified and located within the apple genome. Phylogenetic analysis revealed that MdMAPKs and MdMAPKKs could be divided into 4 subfamilies (groups A, B, C and D), respectively. The predicted MdMAPKs and MdMAPKKs were distributed across 13 out of 17 chromosomes with different densities. In addition, analysis of exon-intron junctions and of intron phase inside the predicted coding region of each candidate gene has revealed high levels of conservation within and between phylogenetic groups. According to the microarray and expressed sequence tag (EST) analysis, the different expression patterns indicate that they may play different roles during fruit development and rootstock-scion interaction process. Moreover, MAPK and MAPKK genes were performed expression profile analyses in different tissues (root, stem, leaf, flower and fruit), and all of the selected genes were expressed in at least one of the tissues tested, indicating that the MAPKs and MAPKKs are involved in various aspects of physiological and developmental processes of apple. To our knowledge, this is the first report of a genome-wide analysis of the apple MAPK and MAPKK gene family. This study provides valuable information for understanding the classification and putative functions of the MAPK signal in apple.
MAPK 信号转导模块在调节植物的许多生物过程中起着至关重要的作用，这些模块由三类层次组织的蛋白激酶组成，即 MAPKKKs、MAPKKs 和 MAPKs。尽管在一些物种中已经进行了该家族的全基因组分析，但对于苹果（Malus domestica）中的 MAPK 和 MAPKK 基因知之甚少。在这项研究中，共鉴定出 26 个假定的苹果 MAPK 基因（MdMPKs）和 9 个假定的苹果 MAPKK 基因（MdMKKs），并将其定位在苹果基因组内。系统发育分析表明，MdMAPKs 和 MdMAPKKs 可分别分为 4 个亚家族（A、B、C 和 D 组）。预测的 MdMAPKs 和 MdMAPKKs 分布在 17 条染色体中的 13 条上，密度不同。此外，对每个候选基因预测编码区的外显子-内含子接头和内含子相位进行分析，揭示了在系统发育组内和组间具有高度的保守性。根据微阵列和表达序列标签（EST）分析，不同的表达模式表明它们在果实发育和砧木-接穗相互作用过程中可能发挥不同的作用。此外，对不同组织（根、茎、叶、花和果实）中的 MAPK 和 MAPKK 基因进行了表达谱分析，所有选定的基因都在至少一种测试组织中表达，这表明 MAPKs 和 MAPKKs 参与了苹果生理和发育过程的各个方面。据我们所知，这是苹果 MAPK 和 MAPKK 基因家族的全基因组分析的首次报道。本研究为理解苹果中 MAPK 信号的分类和潜在功能提供了有价值的信息。
