Identification Of Mitogen Activated Protein Kinases Genes And Screening Of Drought-related MAPK Functional Genes In Potato

Mitogen-activated protein kinases(MAPKs) are significant components of MAPK cascades. MAPK cascades are signaling systems that play pivotal roles in signal transduction processes, mediating cell proliferation, differentiation, stress responses and death in almost all eukaryotes. Thus far, the evolution and expression patterns of MAPKs have been investigated in only a limited number of plants, such as Arabidopsis and rice. However, investigation of MAPK genes especially the drought-related MAPK genes in potato(Solanum tuberosum L.) have remained elusive. The Potato Genome Sequencing information has been completed, which to dissect the information of potato MAPK family members at the genomic level to provide a reliable basis.In this study, we carried out a systematic bioinformatics analysis and identified 15 MAPK genes in potato, named StMAPKs. The chromosome location, promoter region, gene structure, conserved protein motifs and the evolutionary relationship of StMAPKs were analyzed. On the basis of above, Expression profiles of StMAPKs were analyzed under drought stress by q RT-PCR and screened out and functional analysis of drought-related MAPK genes in potato variety ‘Atlantic’. The results are as follows:1. We identified 15 StMAPK genes in the potato genome by bioinformatics analysis method. The encoded polypeptides of 15 StMAPK proteins between 372 aa to 613 aa. The predicted protein molecular weight of StMAPKs varied from 42.69 k Da to 69.71 k Da. The isoelectric point(p I) of the deduced polypeptides were ranged from 4.97 to 9.37. Two StMAPKs each were found on chromosomes 1, 4, 5, 6 and 7, whereas one exists in chromosomes 2, 8, 10, 11 and 12. In addition to the lack of potatoes A group member, MAPK gene family B, C, D group according to the group in Arabidopsis and rice by analysis of conserved motifs and multiple sequence alignments. Which has six members including TEY motif, a member containing MEY motif, including eight members TDY motif.2. Comparative analysis of exon–intron structure of StMAPKs indicated that potato StMAPK genes containing introns. The number of introns varies from 2 to 12. The structure of exons and intron phases are similar among StMAPKs in the same group. we analyzed of the cis-elements in promoter regions. The results show that StMAPKs contain at least two stress response-associated cis-acting elements in their promoter regions, including ABRE, ARE, HSE, LTR, TC-rich repeats, WUN-motif and ERE. These cis-elements may play a significant role in regulating MAPK expression during stress responses in potato.3. Screening of drought-related StMAPK genes were characterized using q RT-PCR to determine their expression patterns in potato leaves under drought stress. The results show that the relative expression levels of StMAPK3, StMAPK10 and StMAPK11 were up-regulated under drought conditions in potato. they play important roles in the regulation of potato plant responses to drought.4. Construction of expression vector of StMAPK3 and rought-related StMAPKs artificial miRNA, genetic transformation to obtained the corresponding transformed plants, the PCR were detected. The results show that the related genes were successfully transferred into potato. For the study of potato transgenic plants resistant physiological characteristics and provide relevant materials, to further clarify the MAPK provide a theoretical basis for potato potential signal transduction mechanisms.