Nuclear localization of <i>Os</i>PIANK1 protein in <i>N. benthamiana</i> leaves.

<p><i>Os</i>PIANK1–GFP exclusively localized in the nucleus of cells in <i>N. benthamiana</i> leaves. Only the green fluorescent (GFP) localized throughout the whole cells. Cells were detected for GFP fluorescence by fluorescence microscopy 48 h after agroinfiltration.</p

<i>OsPIANK1</i> promoter activation in response to inoculation with <i>M.oryzae</i> or exogenous application of MeJA, SA or ABA.

<p>The leaves were harvested at 6 days after inoculation with <i>M.oryzae</i> and 12 h after treatment with the phytohormones. The numbers over the bars indicate the increase in induction of GUS activity compared to the mock. Data represent the means ± SE from the leaf extracts collected from three experimental plant units. (**, *indicate significant differences between the untreated (mock) and treated plants at <i>P</i><0.05 and <i>P</i><0.01, respectively, as determined by the SNK test.).</p

Analysis of resistance to blast fungus in <i>OsPIANK1</i>-overexpressing (OE) rice plants.

<p>(A) Quantitative PCR analysis of <i>OsPIANK1</i> expression in WT and OE plants (3#, 4#, and 6#). Data represent means ± SE of three independent experiments. (B) Lesions in leaves at 6 days after inoculation. The number of expanding lesions (Els) with an area greater than 0.5 mm² per leaf and their mean areas were determined using 10 leaves for WT (Nipponbare) and <i>OsPIANK1</i>-OE plants. Values represent means ± SE. (C) The amount of <i>M. oryzae</i> DNA in the WT and <i>OsPIANK1</i>-OE rice leaves. The leaves were harvested at 6 days after inoculation. Values represent the mean ± SE of three independent experiments. (D) Symptoms of rice blast in <i>OsPIANK1</i>-OE and WT rice plants grown in the greenhouse at 30 days after inoculation with spores of <i>M. oryzae</i> strain guy11. (**,*indicate significant differences between WT and <i>OsPIANK1</i>-OE plants at <i>P</i><0.01 or <i>P</i><0.05, respectively, as determined by the SNK test.).</p

Overexpression of <i>OsPIANK1</i> influenced the expression of a set of genes functioning in SA- and JA-associated pathways during disease resistance against <i>M.oryzae</i> strain guy11 analyzed by quantitative real time-PCR.

<p>Bars represent mean ± SE of three biological replicates. (**, *indicate significant differences between the <i>OsPIANK1-</i>OE and wild-type plants at the same time at <i>P</i><0.01 or <i>P</i><0.05, respectively, as determined by the SNK test.).</p

Nucleotide sequence of 5′ flanking promoter regions and stress-related sequence motifs putatively acting as <i>cis</i>-elements of the <i>OsPIANK1</i> gene.

<p>HSE: <i>cis</i>-acting element involved in heat stress responsiveness. CGTCA-box: <i>cis</i>-acting regulatory element involved in the MeJA-responsiveness. JERE: <i>cis</i>-acting regulatory element involved in the MeJA-responsiveness. ERE: ethylene-responsive element. DRE: <i>cis</i>-acting element involved in dehydration, low-temp, salt stresses. MBS: MYB binding site involved in drought-inducibility. GCC-box: ethylene-responsive element. ABRE: <i>cis</i>-acting element involved in the abscisic acid responsiveness. TCA-element: <i>cis</i>-acting element involved in salicylic acid responsiveness.</p

Image_2_CaHSL1 Acts as a Positive Regulator of Pepper Thermotolerance Under High Humidity and Is Transcriptionally Modulated by CaWRKY40.TIF

Pepper (Capsicum annuum) is an economically important vegetable and heat stress can severely impair pepper growth, development, and productivity. The molecular mechanisms underlying pepper thermotolerance are therefore important to understand but remain elusive. In the present study, we characterized the function of CaHSL1, encoding a HAESA-LIKE (HSL) receptor-like protein kinase (RLK), during the response of pepper to high temperature and high humidity (HTHH). CaHSL1 exhibits the typical structural features of an arginine-aspartate RLK. Transient overexpression of CaHSL1 in the mesophyll cells of Nicotiana benthamiana showed that CaHSL1 localizes throughout the cell, including the plasma membrane, cytoplasm, and the nucleus. CaHSL1 was significantly upregulated by HTHH or the exogenous application of abscisic acid but not by R. solanacearum inoculation. However, CaHSL1 was downregulated by exogenously applied salicylic acid, methyl jasmonate, or ethephon. Silencing of CaHSL1 by virus-induced gene silencing significantly was reduced tolerance to HTHH and downregulated transcript levels of an associated gene CaHSP24. In contrast, transient overexpression of CaHSL1 enhanced the transcript abundance of CaHSP24 and increased tolerance to HTHH, as manifested by enhanced optimal/maximal photochemical efficiency of photosystem II in the dark (Fv/Fm) and actual photochemical efficiency of photosystem II in the light. In addition, CaWRKY40 targeted the promoter of CaHSL1 and induced transcription during HTHH but not in response to R. solanacearum. All of these results suggest that CaHSL1 is directly modulated at the transcriptional level by CaWRKY40 and functions as a positive regulator in the response of pepper to HTHH.</p

Image_2_CaWRKY27 Negatively Regulates H2O2-Mediated Thermotolerance in Pepper (Capsicum annuum).TIF

Heat stress, an important and damaging abiotic stress, regulates numerous WRKY transcription factors, but their roles in heat stress responses remain largely unexplored. Here, we show that pepper (Capsicum annuum) CaWRKY27 negatively regulates basal thermotolerance mediated by H2O2 signaling. CaWRKY27 expression increased during heat stress and persisted during recovery. CaWRKY27 overexpression impaired basal thermotolerance in tobacco (Nicotiana tabacum) and Arabidopsis thaliana, CaWRKY27-overexpressing plants had a lower survival rate under heat stress, accompanied by decreased expression of multiple thermotolerance-associated genes. Accordingly, silencing of CaWRKY27 increased basal thermotolerance in pepper plants. Exogenously applied H2O2 induced CaWRKY27 expression, and CaWRKY27 overexpression repressed the scavenging of H2O2 in Arabidopsis, indicating a positive feedback loop between H2O2 accumulation and CaWRKY27 expression. Consistent with this, CaWRKY27 expression was repressed under heat stress in the presence H2O2 scavengers and CaWRKY27 silencing decreased H2O2 accumulation in pepper leaves. These changes may result from changes in levels of reactive oxygen species (ROS)-scavenging enzymes, since the heat stress-challenged CaWRKY27-silenced pepper plants had significantly higher expression of multiple genes encoding ROS-scavenging enzymes, such as CaCAT1, CaAPX1, CaAPX2, CaCSD2, and CaSOD1. Therefore, CaWRKY27 acts as a downstream negative regulator of H2O2-mediated heat stress responses, preventing inappropriate responses during heat stress and recovery.</p

Additional file 7 of A cysteine-rich receptor-like protein kinase CaCKR5 modulates immune response against Ralstonia solanacearum infection in pepper

Additional file 7. Melting curves in real time PCR

Additional file 5 of A cysteine-rich receptor-like protein kinase CaCKR5 modulates immune response against Ralstonia solanacearum infection in pepper

Additional file 5. Original images for Fig. 4a, Fig. 5a and Fig. 6b

Additional file 4 of A cysteine-rich receptor-like protein kinase CaCKR5 modulates immune response against Ralstonia solanacearum infection in pepper

Additional file 4. Photobleaching phenotype of peppers infiltrated with TRV:CaPDS for 15 d