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

Abstract

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 Capsicum annuum. Herein, genome-wide identification and transcriptional expression analysis of MAPK and MAPK kinase (MAPKK) were performed in pepper. A total of 19 pepper MAPK (CaMAPKs) genes and five MAPKK (CaMAPKKs) genes were identified. Phylogenetic analysis indicated that CaMAPKs and CaMAPKKs 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 MAPK and MAPKK genes were ubiquitously expressed and transcriptionally modified in pepper leaves after treatments with heat, salt, and Ralstonia solanacearum 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.

Genome-Wide Identification, Evolution, and Co-expression Network Analysis of Mitogen-Activated Protein Kinase Kinase Kinases in Brachypodium distachyon

“…Gene structure analysis could contribute to better understanding its functions, regulation, and evolution (Liu et al, 2015 ). In order to get some insight into the gene structure of BdMAPKKK genes, the exon/intron organization of them was analyzed (Figure 3 ).…”

In silicoanalysis reveals widespread presence of three gene families, MAPK, MAPKK and MAPKKK, of the MAPK cascade from crop plants ofSolanaceaein comparison to the distantly-related syntenic species fromRubiaceae,coffee

“…Furthermore, 108 sequences from potato, 63 from eggplant, 79 from pepper, and 64 from coffee have been reported in this study based on perfectly conserved signature motifs belonging to the three major families of the MAPK cascade. Although, few members of some of these families were reported recently ( Daigle & Matton, 2015 ; Kong et al, 2012 ; Lazar et al, 2014 ; Liu et al, 2015 ; Mohanta et al, 2015 ; Wu et al, 2014 ), this articles reports the largest set of genes identified from all three of these gene families and their further subfamilies in the said species. Phylogenetic analysis of the reported sequences shows the conservation of the genes throughout the Solanaceae plant family and coffee, which is closely related to Solanaceae species in terms of its genetic make-up.…”

“…Identification of the three complete families of the MAPK cascade has not been done earlier in potato, eggplant, pepper, and coffee. However, being widely studied due to their vital functions, a few of these genes have recently been identified and reported as MPK, MKK, and MAPKKK in tomato ( Daigle & Matton, 2015 ; Kong et al, 2012 ; Lazar et al, 2014 ; Mohanta et al, 2015 ; Wu et al, 2014 ); as MPK, MKK, and MEKK-like from MAPKKK in potato ( Daigle & Matton, 2015 ; Lazar et al, 2014 ; Mohanta et al, 2015 ); and, as MPK and MKK in pepper ( Liu et al, 2015 ). However, genome identification of the three complete gene families hasn’t been reported for any one of them; thus, such an identification will be a huge step forward towards unraveling their functionality and importance.…”

Genome-wide identification and role of MKK and MPK gene families in clubroot resistance of Brassica rapa

“…rapa ; these genes were divided into four groups as in A . thaliana , rice, and other plant species [ 3 , 11 , 33 , 34 ]. The use of a pair of near isogenic lines, CR BJN3-2 and CS BJN3-2, allowed us to identify the probable BraMKK and BrMPK genes participating in B .…”