<i>GhWRKY40</i> overexpression enhances susceptibility to <i>R. Solanacearum</i> in transgenic plants.

<p>(A) Phenotype of WT and OE lines after 5 days of incubation with <i>R. solanacearum</i>. (B–C) Relative transcript levels of defense-related genes in non-infected and infected WT and OE plants were analyzed by qPCR. The data are presented as the mean ± standard error of three independent experiments. The values indicated by the different letters are significantly different at P<0.01, as determined using Duncan's multiple range tests.</p

Putative <i>cis</i>-elements in the <i>GhWRKY40</i> promoter.

<p>Putative <i>cis</i>-elements in the <i>GhWRKY40</i> promoter.</p

<i>GhWRKY40</i>, a Multiple Stress-Responsive Cotton WRKY Gene, Plays an Important Role in the Wounding Response and Enhances Susceptibility to <i>Ralstonia solanacearum</i> Infection in Transgenic <i>Nicotiana benthamiana</i>

<div><p>WRKY transcription factors form one of the largest transcription factor families and function as important components in the complex signaling processes that occur during plant stress responses. However, relative to the research progress in model plants, far less information is available on the function of WRKY proteins in cotton. In the present study, we identified the <i>GhWRKY40</i> gene in cotton (<i>Gossypium hirsutum</i>) and determined that the GhWRKY40 protein is targeted to the nucleus and is a stress-inducible transcription factor. The <i>GhWRKY40</i> transcript level was increased upon wounding and infection with the bacterial pathogen <i>Ralstonia solanacearum</i>. The overexpression of <i>GhWRKY40</i> down-regulated most of the defense-related genes, enhanced the wounding tolerance and increased the susceptibility to <i>R. solanacearum</i>. Consistent with a role in multiple stress responses, we found that the <i>GhWRKY40</i> transcript level was increased by the stress hormones salicylic acid (SA), methyl jasmonate (MeJA) and ethylene (ET). Moreover, GhWRKY40 interacted with the MAPK kinase GhMPK20, as shown using yeast two-hybrid and bimolecular fluorescence complementation systems. Collectively, these results suggest that <i>GhWRKY40</i> is regulated by SA, MeJA and ET signaling and coordinates responses to wounding and <i>R. solanacearum</i> attack. These findings highlight the importance of WRKYs in regulating wounding- and pathogen-induced responses.</p></div

Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice-1

Al MySQL database. The whole program is available in additional file (see Additional file and ).<p><b>Copyright information:</b></p><p>Taken from "Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice"</p><p>http://www.biomedcentral.com/1471-2164/9/44</p><p>BMC Genomics 2008;9():44-44.</p><p>Published online 27 Jan 2008</p><p>PMCID:PMC2267713.</p><p></p

Analysis of ROS accumulation after wounding in WT and OE plants.

<p>(A–B) Wound-induced H₂O₂ and O₂⁻ accumulation, as detected via DAB staining and NBT staining, respectively. (C) The phenotype of leaf disks from WT and OE plants that were incubated in different concentrations of MV (0, 200, 400 or 600 mM). (D) Relative chlorophyll content in the leaf disks from (C). Disks floated in water were used as a control. The presented data are the means ± standard error of three independent experiments. The different letters above the columns indicate significant differences (P<0.01) according to Duncan's multiple range test, which was performed using SAS version 9.1 software.</p

Characterization and sequence analysis of GhWRKY40.

<p>(A) Alignment of the amino acid sequences of GhWRKY40 and the representative related proteins AtWRKY18 (NP_567882), BnWRKY18 (ACN89257), AtWRKY40 (NP_178199) and BnWRKY40 (ACQ76806). Amino acids with 100% identity are shaded in black. The approximately 60-amino acid WRKY domain and the C and H residues in the zinc-finger motif (C-X_4–5-C-X_22–23-H-X₁-H) are marked by a two-headed arrow and dot, respectively. The highly conserved amino acid sequence WRKYGQK in the WRKY domain is boxed. The putative nuclear localization signals are marked by lines. (B) Phylogenetic relationship between GhWRKY40 and other plant WRKY proteins. A neighbor-joining phylogenetic tree was created using MEGA 4.1 software. GhWRKY40 is boxed. Each gene name is followed by its protein ID. The abbreviations of the gene names are indicated as follows: Gh, <i>Gossypium hirsutum</i>; At, <i>Arabidopsis thaliana</i>; Os, <i>Oryza sativa</i>; Bn, <i>Brassica napus</i>; Cs, <i>Cucumis sativus</i> and Gm, <i>Glycine max</i>.</p

Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice-3

Een boxes indicate the duplicated segmental regions resulting from the most recent polyploidy. Only the duplicated regions containing CCCH genes are shown. Blue lines connect corresponding sister gene pairs in duplicated blocks. AtC3H1 and AtC3H51, AtC3H8 and AtC3H60, AtC3H12 and AtC3H28, AtC3H14 and AtC3H15, AtC3H30 and AtC3H56, AtC3H46 and AtC3H55, AtC3H59 and AtC3H62 are potential duplicated gene pairs which are marked with the same color rectangle, as described in the text.<p><b>Copyright information:</b></p><p>Taken from "Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice"</p><p>http://www.biomedcentral.com/1471-2164/9/44</p><p>BMC Genomics 2008;9():44-44.</p><p>Published online 27 Jan 2008</p><p>PMCID:PMC2267713.</p><p></p

Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice-2

Ng tree: The unrooted tree, constructed using ClustalX (1.83), summarizes the evolutionary relationship among the 68 members of CCCH families. The neighbor-joining tree was constructed using aligned full-length amino acid sequences. The proteins are named according to their gene name (see Table 2) with the CCCH zinc finger number of each protein. The tree shows the 11 major phylogenetic subfamilies (left column, numbered I to XI and marked with different alternating tones of a gray background to make subfamily identification easier) with high predictive value. The numbers beside the branches represent bootstrap values (≥500) based on 1000 replications that were used to class the major 11 subfamilies. Gene structure: The gene structure is presented by black exon(s) and spaces between the black boxes correspond to introns. The sizes of exons and introns can be estimated using the horizontal lines. Protein structure: Each black box represents the motif in the protein, as indicated in the table on the left side. The conserved motifs outside CCCH motif are highlighted with an arranged number, and the same number referred to the same motif. The length of the motif can be estimated using the scale at top. aa, amino acids.<p><b>Copyright information:</b></p><p>Taken from "Genome-wide analysis of CCCH zinc finger family in Arabidopsis and rice"</p><p>http://www.biomedcentral.com/1471-2164/9/44</p><p>BMC Genomics 2008;9():44-44.</p><p>Published online 27 Jan 2008</p><p>PMCID:PMC2267713.</p><p></p

Expression of the <i>GhWRKY40</i> gene in response to stress.

<p>Seven-day-old cotton seedlings in hydroponic culture were treated with <i>R. solanacearum</i> (A), wounding (B), 100 µM H₂O₂ (C), 100 µM MeJA (D), 2 mM SA (E) or 5 mM ET released from ethephon (F). Total RNA was isolated at the indicated times after the treatment and subjected to qPCR analysis. The <i>ubiquitin</i> gene was employed as an internal control. This experiment was repeated at least twice. The values indicated by the different letters are significantly different at P<0.01, as determined using Duncan's multiple range tests.</p

qPCR analysis of stress-related gene expression in WT and OE plants under normal conditions (A) and after wounding (B).

<p>The data are presented as the mean ± standard error of three independent experiments. The values indicated by the different letters are significantly different at P<0.01, as determined using Duncan's multiple range tests.</p