AUTHOR=He Shuilin , liu zhiqin , shi lanping , liu yanyan , shen lei , yang sheng , cai jinsen , tang qian , yu huanxin , wang rongzhang , wen jiayu , lin youquan , hu jiong , liu cailing , mou shaoliang 

TITLE=Genome-wide identification and transcriptional expression analysis of mitogen-activated protein kinase and mitogen-activated protein kinase kinase genes in Capsicum annuum

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00780

DOI=10.3389/fpls.2015.00780

ISSN=1664-462X

ABSTRACT=<p>The tripartite mitogen-activated protein kinase (MAPK) signaling cascades have been implicated in plant growth, development, and environment adaptation, but a comprehensive understanding of MAPK signaling at genome-wide level is limited in <italic>Capsicum annuum</italic>. Herein, genome-wide identification and transcriptional expression analysis of MAPK and MAPK kinase (MAPKK) were performed in pepper. A total of 19 pepper <italic>MAPK</italic> (<italic>CaMAPKs</italic>) genes and five <italic>MAPKK</italic> (<italic>CaMAPKKs</italic>) genes were identified. Phylogenetic analysis indicated that <italic>CaMAPKs</italic> and <italic>CaMAPKKs</italic> could be classified into four groups and each group contains similar exon-intron structures. However, significant divergences were also found. Notably, five members of the pepper MAPKK family were much less conserved than those found in Arabidopsis, and 9 Arabidopsis MAPKs did not have orthologs in pepper. Additionally, 7 MAPKs in Arabidopsis had either two or three orthologs in the pepper genome, and six pepper MAPKs and one MAPKK differing in sequence were found in three pepper varieties. Quantitative real-time RT-PCR analysis showed that the majority of <italic>MAPK</italic> and <italic>MAPKK</italic> genes were ubiquitously expressed and transcriptionally modified in pepper leaves after treatments with heat, salt, and <italic>Ralstonia solanacearum</italic> inoculation as well as exogenously applied salicylic acid, methyl jasmonate, ethephon, and abscisic acid. The MAPKK-MAPK interactome was tested by yeast two-hybrid assay, the results showed that one MAPKK might interact with multiple MAPKs, one MAPK might also interact with more than one MAPKKs, constituting MAPK signaling networks which may collaborate in transmitting upstream signals into appropriate downstream cellular responses and processes. These results will facilitate future functional characterization of MAPK cascades in pepper.</p>