Table 1.
Information on the MAPK gene family in strawberry.
Fig 1.
Phylogenetic analysis of MAPKs from strawberry, Arabidopsis, apple, grape, maize, rice, and tomato.
The neighbor-joining tree was created using the MEGA6.0 program with the p-distance model, using full-length sequences of 12 strawberry (Fv), 20 Arabidopsis (At), 26 apple (Md), 14 grape (Vv), 19 maize (Zm), 17 rice (Os), and 16 tomato (Sl) MAPK proteins. The bootstrap value was set to 1000 replicates. FvMAPKs are highlighted in red, and the other MAPKs are shown in different colors.
Fig 2.
Multiple sequence alignment of the kinase domains of strawberry MAPK proteins.
(A) Eukaryotic MAPK kinase primary structure: blue areas represent regions containing the eleven domains (I–XI) that are found in all serine/threonine protein kinases; gray areas indicate regions that are less conserved. (B) Alignment of the kinase domains for 12 strawberry MAPK proteins. Alignment was performed using ClustalX 2.0.12 and displayed using GeneDoc. Identical sequences are highlighted in black, and similar residues are shown in gray shading. The 11 kinase domains are highlighted using Roman numerals (I to XI) above the sequence. The P-loop, C-loop, activation-loop motifs and CD domain are indicated by red boxes above the alignments. The conserved threonine and tyrosine residues TXY are indicated using asterisks. Fv: F. vesca.
Fig 3.
Phylogenetic analysis and domain organization of strawberry MAPKs.
The unrooted phylogenetic tree was generated using the MEGA6.0 program with the neighbor-joining method. Bootstrap supports from 1000 replicates are indicated at each branch. The domain organizations were analyzed by scanning the protein sequences for the conserved domains using the InterProScan program.
Fig 4.
Structural analysis of strawberry MAPK genes.
Conserved motif of the strawberry MAPK genes are shown on the left and are denoted by rectangles with different colors. Exon-intron organization of the strawberry MAPK genes are shown on the right, with exons and introns represented by orange double-sided wedges and purple lines, respectively; untranslated regions (UTRs) are indicated using blue rectangles.
Fig 5.
Cis-regulatory element analysis of the promoter regions of strawberry MAPK genes.
Different cis-regulatory elements are indicated by different color round-corner rectangles and placed in their relative position on the promoter. Round-corner rectangles presented above the line indicate the forward strand of DNA, while those below indicate the reverse strand (detailed results shown in S2 Table).
Fig 6.
Predicted subcellular localization of the FvMAPKs.
A schematic representation of the subcellular localization of the FvMAPK proteins based on four different online programs (detailed results shown in S3 Table). Red FvMAPKs indicate localization prediction by WoLF PSORT; blue FvMAPKs indicate localization prediction by CELLO v2.5; purple FvMAPKs indicate localization prediction by Plant-PLoc; green FvMAPKs indicate localization prediction by ProtComp 9.0. ER, endoplasmic reticulum; PM, plasma membrane; GA, Golgi apparatus; Extr, extracellular.
Fig 7.
Transcript profiles of MAPK genes in the diploid woodland strawberry (F. vesca) during different stress treatments.
Biotic and abiotic stress treatments (powdery mildew, 4°C, 42°C, drought, and salt) (A) and hormone treatments (ABA, ETH, MeJA, and SA) were applied to the plants, and the transcript profiles were generated using semi-quantitative PCR (original results shown in S3–S7 Figs). The color scale represents relative transcript levels with increased (red) or decreased (green) transcript abundance. The experiments were repeated three times, and the results were consistent.
Fig 8.
RT-qPCR analysis of six MAPK genes in the diploid woodland strawberry (F. vesca) in response to powdery mildew infection, 4°C, 42°C, drought, and NaCl treatments.
The experiments were repeated three times, and the results were consistent. The mean values and SDs were obtained from three biological and three technical replicates. The asterisks indicate that the corresponding gene was significantly up- or down-regulated in response to treatment, as determined by Student’s t-test (* P < 0.05, ** P < 0.01).
Fig 9.
RT-qPCR analysis of six MAPK genes in the diploid woodland strawberry (F. vesca) in response to ABA, Eth, MeJA, and SA treatments.
The experiments were repeated three times and yielded consistent results. The mean values and SDs were obtained from three biological and three technical replicates. The asterisks indicate that the corresponding gene was significantly up- or down-regulated in response to treatment, as determined by Student’s t-test (* P < 0.05, ** P < 0.01).
Fig 10.
Interaction network analysis of MAPK proteins identified in strawberry and related genes in Arabidopsis.
The line thickness relates to the combined score. The homologous genes of strawberry are presented in red font in parentheses.
Table 2.
The number of MAPK genes in Arabidopsis, strawberry, apple, grape, tomato, maize, and rice.