Genome-Wide Identification and Analysis Uncovers the Potential Role of JAZ and MYC Families in Potato under Abiotic Stress

Abstract

As key regulators of the Jasmonates (JAs) signal transduction pathway, JAZ protein, and MYC transcription factors are imperative for plant response to external environmental changes, growth, and development. In this study, 18 StJAZs and 12 StMYCs were identified in potatoes. Their chromosomal position, phylogenetic development, gene structure, and promoter cis-acting parts of the StJAZ genes were analyzed. In addition, Protein-Protein Interaction (PPI) network analysis of StJAZ and StMYC gene families and yeast two-hybrid assay demonstrated that five StMYCs can interact with 16 StJAZs, which provides new insights into the operation mechanism of StJAZs and StMYCs in JA signal response. Moreover, we explored the expression profiles of StJAZs and StMYCs genes in different tissues and during abiotic stresses by RNA-seq data. Based on the PPI network and transcriptome data, the genes StJAZ11, StJAZ16, and StMYC6 were chosen for further qRT-PCR study under salt or mannitol treatment. Under mannitol-induced drought or salinity treatment, the expression patterns of StMYC6, StJAZ11, and StJAZ16 were different, indicating that the JAZ protein and MYC transcription factor may be engaged in the response of potatoes to abiotic stress, which opened up a new research direction for the genetic improvement of potatoes in response to environmental stress.

Keywords: JAZ family; MYC family; abiotic stress; potato; protein interaction.

Figure 1

Genomic distributions of StJAZ and StMYC genes on 10 potato chromosomes (chromosomes are represented by bars, with chromosome numbers displayed at the top of the bars and gene names listed on the right. The relative chromosomal position of each gene is represented by the unit Mbp and marked on the black line on the left).

Figure 2

Phylogenetic tree of potato, tomato, rice, Arabidopsis, and physcomitrella patens JAZs and MYCs. (A) The Phylogenetic tree of JAZs; (B) The Phylogenetic tree of MYCs. Circles represent tomato; the squares represent rice; the triangle represents Arabidopsis; the hooks represent physcomitrella patens; and the stars represent potato.

Figure 3

StJAZ and StMYC genes Structure and motif. (A) The gene structure analysis of StJAZ; (B) The motif composition in potato JAZ proteins; (C) The exon–intron structure of StMYC; (D) The motif composition of StMYC proteins. UTRs are represented by green rectangles, exons by yellow rectangles, and introns by black lines.

Figure 4

StJAZ genes promoter cis-acting elements. The different colors and numbers in the circle represent the number of cis-acting elements in the promoter area of the StJAZs. As the number in the circle increases, the color of the circle becomes darker.

Figure 5

PPI network analysis of StJAZ and StMYC genes. (A) The PPI network of StJAZs and StMYCs; (B) The result of self-activation detection; (C) Yeast two−hybrid interactions between StJAZ proteins and StMYCs.

Figure 6

Expression patterns of StJAZ and StMYC genes with interactions and their responses to abiotic stress. (A) StJAZ and StMYC expression patterns in various tissues. (B) Expression patterns of StJAZs and StMYCs in different treatments. (C) Analysis of the expression of StJAZ11, StJAZ16, and StMYC6 by quantitative real-time (qRT)-PCR.