Table 1.
Watermelon WRKY genes and their related information.
Fig 1.
Alignment of 63 ClWRKY and 7 AtWRKY domain amino acid sequences.
Alignment was accomplished using MUSCLE. ‘N’ and ‘C’ indicate the N-terminal and C-terminal WRKY domain of a specific WRKY protein, respectively. The amino acids forming the zinc-finger motif are highlighted in blue, the conserved WRKY amino acid domains is highlighted in green.
Fig 2.
The phylogenetic tree of 184 WRKY genes among watermelon (red), Arabidopsis (blue) and cucumber (black).
The domains clustered into three major groups I, II, III, and five subgroups (a, b, c, d, and e) in group II.
Fig 3.
Illustration of the gene structure of 57 ClWRKY transcription factors.
Genes were separated into their respective groups with different colors. Exons were shown using green round-corner rectangle while introns were shown using black solid lines (5′-3′).
Fig 4.
Schematic representation of 24 conserved motifs in watermelon WRKY proteins.
Conserved motifs were named as motif 1 to motif 24, and different motif was shown as colored boxes with their names in the center of the boxes. The colored boxes were ordered manually according to the results of the MEME analysis. The length of each box in the figure does not represent the actual motif size.
Fig 5.
Synteny analysis of watermelon WRKY genes.
Chromosomes 1–11 were shown with different colors and in a circular form. Colored curves indicated the details of syntenic regions in watermelon genome.
Fig 6.
Synteny analysis between watermelon and Arabidopsis WRKY genes.
The chromosomes of watermelon and Arabidopsis are depicted as a circle. Colored curves denote the details of syntenic regions between watermelon and Arabidopsis WRKY genes.
Fig 7.
Expression profiles of ClWRKY genes in various tissues of ‘Y34’ by semi-quantitative RT-PCR analyses.
β-actin gene was used as the internal control. Six amplified bands from left to right for each WRKY gene represent amplified products from R: root; S: stem; L: leaf; T: tendril; FF: female flower; MF: male flower and F: fruit.
Fig 8.
Expression patterns of ClWRKY genes under abiotic stresses by qRT-PCR.
The abiotic stresses used for expression patterns are indicated at the top. Scale bars on the top of each heat map represent log2-transformed (Treatment/Control) values, with red as increased expressed level and green as decreased expressed level. (A) Expression of ClWRKY genes under drought stress, and 24, 48, 96, and 192 indicate hours after treatment. (B) Expression of ClWRKY genes under 4°C treatment, and 1, 3, 6, 12, 24, and 48 indicate hours after treatment. (C) Expression of ClWRKY genes under salt stress treatment, and 6, 24, 48, 72, 96, and 120 indicate hours after treatment.
Fig 9.
Expression patterns of ClWRKY genes under exogenous hormone treatments.
Scale bars on the top of each heat map represent log2-transformed (Treatment/Control) values. The hormone treatments including abscisic acid (ABA), methyl jasmonic acid (MeJA), salicylic acid (SA) and ethephon (ETH) are shown as heatmaps (A), (B), (C) and (D), respectively. 0.5, 1, 6, 12, 24 and 48 indicate hours after treatment.