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GhMPK16, a novel stress-responsive group D MAPK gene from cotton, is involved in disease resistance and drought sensitivity.

Shi J, Zhang L, An H, Wu C, Guo X - BMC Mol. Biol. (2011)

Bottom Line: In this study, we isolated and characterised GhMPK16, the first group D MAPK gene found in cotton.Furthermore, transgenic Arabidopsis showed reduced drought tolerance and rapid H2O2 accumulation.These results suggest that GhMPK16 might be involved in multiple signal transduction pathways, including biotic and abiotic stress signaling pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong 271018, China.

ABSTRACT

Background: Mitogen-activated protein kinase (MAPK) cascades play pivotal roles in mediating biotic and abiotic stress responses. In plants, MAPKs are classified into four major groups (A-D) according to their sequence homology and conserved phosphorylation motifs. Members of group A and B have been extensively characterized, but little information on the group D MAPKs has been reported.

Results: In this study, we isolated and characterised GhMPK16, the first group D MAPK gene found in cotton. Southern blot analysis suggests GhMPK16 is single copy in the cotton genome, and RNA blot analysis indicates that GhMPK16 transcripts accumulate following pathogen infection and treatment with multiple defense-related signal molecules. The analysis of the promoter region of GhMPK16 revealed a group of putative cis-acting elements related to stress responses. Subcellular localization analysis suggests that GhMPK16 acts in the nucleus. Transgenic Arabidopsis overexpressing GhMPK16 displayed significant resistance to fungi (Colletotrichum nicotianae and Alternaria alternata) and bacteria (Pseudomonas solanacearum) pathogen, and the transcripts of pathogen-related (PR) genes were more rapidly and strongly induced in the transgenic plants. Furthermore, transgenic Arabidopsis showed reduced drought tolerance and rapid H2O2 accumulation.

Conclusion: These results suggest that GhMPK16 might be involved in multiple signal transduction pathways, including biotic and abiotic stress signaling pathways.

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Inhibition of fungal pathogen infections in GhMPK16-overexpressing Arabidopsis lines. (A) Disease symptoms of leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with C. nicotianae (106 conidia/ml). (B) The diameter (mm) of the lesions was measured 5 d after inoculation with C. nicotianae. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with P < 0.05 according to Duncan's multiple range test. (C) Disease symptoms of the leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with A. alternate (106 conidia/ml). (D) The diameter (mm) of the lesions was measured 5 d after inoculation with A. alternate. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with a P < 0.05 according to Duncan's multiple range test.
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Figure 7: Inhibition of fungal pathogen infections in GhMPK16-overexpressing Arabidopsis lines. (A) Disease symptoms of leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with C. nicotianae (106 conidia/ml). (B) The diameter (mm) of the lesions was measured 5 d after inoculation with C. nicotianae. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with P < 0.05 according to Duncan's multiple range test. (C) Disease symptoms of the leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with A. alternate (106 conidia/ml). (D) The diameter (mm) of the lesions was measured 5 d after inoculation with A. alternate. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with a P < 0.05 according to Duncan's multiple range test.

Mentions: As shown in Figure 7, GhMPK16-overexpressing plants were evaluated for their resistance to fungal pathogens (C. nicotianae and A. alternate). Detached leaves were inoculation with C. nicotianae and A. alternate, and after 5 days, the lesions in the wild-type leaves were larger than those in the transgenic leaves, and line #2, which displayed the highest level of GhMPK16 expression, exhibited the least severe disease symptoms. To quantify the lesions, the diameters of the disease spots were measured, and the data were consistent with the visual observations. These results indicate that GhMPK16 can enhance resistance to infections by pathogenic fungi in transgenic plants. After inoculating whole plants with C. nicotianae and A. alternate, the expression of AtPR1, AtPR4 and AtPDF1.2 was observed at 3- and 6-day post-infection in both the wild-type and transgenic plants, and the expression patterns of the three marker genes were similar to those observed with the P. solanacearum challenge (data not shown).


GhMPK16, a novel stress-responsive group D MAPK gene from cotton, is involved in disease resistance and drought sensitivity.

Shi J, Zhang L, An H, Wu C, Guo X - BMC Mol. Biol. (2011)

Inhibition of fungal pathogen infections in GhMPK16-overexpressing Arabidopsis lines. (A) Disease symptoms of leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with C. nicotianae (106 conidia/ml). (B) The diameter (mm) of the lesions was measured 5 d after inoculation with C. nicotianae. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with P < 0.05 according to Duncan's multiple range test. (C) Disease symptoms of the leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with A. alternate (106 conidia/ml). (D) The diameter (mm) of the lesions was measured 5 d after inoculation with A. alternate. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with a P < 0.05 according to Duncan's multiple range test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3117701&req=5

Figure 7: Inhibition of fungal pathogen infections in GhMPK16-overexpressing Arabidopsis lines. (A) Disease symptoms of leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with C. nicotianae (106 conidia/ml). (B) The diameter (mm) of the lesions was measured 5 d after inoculation with C. nicotianae. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with P < 0.05 according to Duncan's multiple range test. (C) Disease symptoms of the leaves from wild-type (WT) and transgenic plants (#2 and #5) 5 d after inoculation with A. alternate (106 conidia/ml). (D) The diameter (mm) of the lesions was measured 5 d after inoculation with A. alternate. Data are the mean ± SE (n = 6) from three independent experiments. Different letters indicate significant differences with a P < 0.05 according to Duncan's multiple range test.
Mentions: As shown in Figure 7, GhMPK16-overexpressing plants were evaluated for their resistance to fungal pathogens (C. nicotianae and A. alternate). Detached leaves were inoculation with C. nicotianae and A. alternate, and after 5 days, the lesions in the wild-type leaves were larger than those in the transgenic leaves, and line #2, which displayed the highest level of GhMPK16 expression, exhibited the least severe disease symptoms. To quantify the lesions, the diameters of the disease spots were measured, and the data were consistent with the visual observations. These results indicate that GhMPK16 can enhance resistance to infections by pathogenic fungi in transgenic plants. After inoculating whole plants with C. nicotianae and A. alternate, the expression of AtPR1, AtPR4 and AtPDF1.2 was observed at 3- and 6-day post-infection in both the wild-type and transgenic plants, and the expression patterns of the three marker genes were similar to those observed with the P. solanacearum challenge (data not shown).

Bottom Line: In this study, we isolated and characterised GhMPK16, the first group D MAPK gene found in cotton.Furthermore, transgenic Arabidopsis showed reduced drought tolerance and rapid H2O2 accumulation.These results suggest that GhMPK16 might be involved in multiple signal transduction pathways, including biotic and abiotic stress signaling pathways.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, Shandong 271018, China.

ABSTRACT

Background: Mitogen-activated protein kinase (MAPK) cascades play pivotal roles in mediating biotic and abiotic stress responses. In plants, MAPKs are classified into four major groups (A-D) according to their sequence homology and conserved phosphorylation motifs. Members of group A and B have been extensively characterized, but little information on the group D MAPKs has been reported.

Results: In this study, we isolated and characterised GhMPK16, the first group D MAPK gene found in cotton. Southern blot analysis suggests GhMPK16 is single copy in the cotton genome, and RNA blot analysis indicates that GhMPK16 transcripts accumulate following pathogen infection and treatment with multiple defense-related signal molecules. The analysis of the promoter region of GhMPK16 revealed a group of putative cis-acting elements related to stress responses. Subcellular localization analysis suggests that GhMPK16 acts in the nucleus. Transgenic Arabidopsis overexpressing GhMPK16 displayed significant resistance to fungi (Colletotrichum nicotianae and Alternaria alternata) and bacteria (Pseudomonas solanacearum) pathogen, and the transcripts of pathogen-related (PR) genes were more rapidly and strongly induced in the transgenic plants. Furthermore, transgenic Arabidopsis showed reduced drought tolerance and rapid H2O2 accumulation.

Conclusion: These results suggest that GhMPK16 might be involved in multiple signal transduction pathways, including biotic and abiotic stress signaling pathways.

Show MeSH
Related in: MedlinePlus