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Mitogen-activated protein kinases are associated with the regulation of physiological traits and virulence in Fusarium oxysporum f. sp. cubense.

Ding Z, Li M, Sun F, Xi P, Sun L, Zhang L, Jiang Z - PLoS ONE (2015)

Bottom Line: Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid.Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2.Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Pathology, South China Agricultural University, Guangzhou 510642, China; Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.

ABSTRACT
Fusarium oxysporum f. sp. cubense (FOC) is an important soil-borne fungal pathogen causing devastating vascular wilt disease of banana plants and has become a great concern threatening banana production worldwide. However, little information is known about the molecular mechanisms that govern the expression of virulence determinants of this important fungal pathogen. In this study, we showed that mutation of three mitogen-activated protein (MAP) kinase genes, designated as FoSlt2, FoMkk2 and FoBck1, respectively, led to substantial attenuation in fungal virulence on banana plants. Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid. Biochemical analysis further confirmed the essential role of MAP kinases in modulating the production of fusaric acid, which was a crucial phytotoxin in accelerating development of Fusarium wilt symptoms in banana plants. Additionally, we found that the MAP kinase FoSlt2 was required for siderophore biosynthesis under iron-depletion conditions. Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2. Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence.

No MeSH data available.


Related in: MedlinePlus

Quantification of chitin and expression of chitin synthase genes.(A) Chitin content in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1, complemented strains ΔFoSlt2-c and ΔFoMkk2-c. (B) Quantitative real-time PCR analysis of chitin synthase in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1. The seven chitin synthase are FOIG_07229, FOIG_10825, FOIG_09216, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723. Error bars indicate the standard error from three replicates.
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pone.0122634.g003: Quantification of chitin and expression of chitin synthase genes.(A) Chitin content in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1, complemented strains ΔFoSlt2-c and ΔFoMkk2-c. (B) Quantitative real-time PCR analysis of chitin synthase in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1. The seven chitin synthase are FOIG_07229, FOIG_10825, FOIG_09216, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723. Error bars indicate the standard error from three replicates.

Mentions: Chitin is one of the major components of the Fusarium oxysporum cell wall [16]. The mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1 showed lower chitin contents than WT and the complemented strains ΔFoSlt2-c and ΔFoMkk2-c (Fig 3A). Given that synthesis of chitin is dependent on the activity of chitin synthase [17], we analyzed the expression levels of seven chitin synthases with quantitative real-time PCR. As expected, the results showed that except for FOIG_00580 and FOIG_06723 in the mutant ΔFoBck1, the expression levels of five chitin synthase genes including FOIG_07229, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723 were reduced significantly in the three mutants compared with the WT control (Fig 3B).


Mitogen-activated protein kinases are associated with the regulation of physiological traits and virulence in Fusarium oxysporum f. sp. cubense.

Ding Z, Li M, Sun F, Xi P, Sun L, Zhang L, Jiang Z - PLoS ONE (2015)

Quantification of chitin and expression of chitin synthase genes.(A) Chitin content in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1, complemented strains ΔFoSlt2-c and ΔFoMkk2-c. (B) Quantitative real-time PCR analysis of chitin synthase in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1. The seven chitin synthase are FOIG_07229, FOIG_10825, FOIG_09216, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723. Error bars indicate the standard error from three replicates.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4388850&req=5

pone.0122634.g003: Quantification of chitin and expression of chitin synthase genes.(A) Chitin content in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1, complemented strains ΔFoSlt2-c and ΔFoMkk2-c. (B) Quantitative real-time PCR analysis of chitin synthase in WT, mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1. The seven chitin synthase are FOIG_07229, FOIG_10825, FOIG_09216, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723. Error bars indicate the standard error from three replicates.
Mentions: Chitin is one of the major components of the Fusarium oxysporum cell wall [16]. The mutants ΔFoSlt2, ΔFoMkk2 and ΔFoBck1 showed lower chitin contents than WT and the complemented strains ΔFoSlt2-c and ΔFoMkk2-c (Fig 3A). Given that synthesis of chitin is dependent on the activity of chitin synthase [17], we analyzed the expression levels of seven chitin synthases with quantitative real-time PCR. As expected, the results showed that except for FOIG_00580 and FOIG_06723 in the mutant ΔFoBck1, the expression levels of five chitin synthase genes including FOIG_07229, FOIG_00580, FOIG_06735, FOIG_06738 and FOIG_06723 were reduced significantly in the three mutants compared with the WT control (Fig 3B).

Bottom Line: Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid.Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2.Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Pathology, South China Agricultural University, Guangzhou 510642, China; Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China.

ABSTRACT
Fusarium oxysporum f. sp. cubense (FOC) is an important soil-borne fungal pathogen causing devastating vascular wilt disease of banana plants and has become a great concern threatening banana production worldwide. However, little information is known about the molecular mechanisms that govern the expression of virulence determinants of this important fungal pathogen. In this study, we showed that mutation of three mitogen-activated protein (MAP) kinase genes, designated as FoSlt2, FoMkk2 and FoBck1, respectively, led to substantial attenuation in fungal virulence on banana plants. Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid. Biochemical analysis further confirmed the essential role of MAP kinases in modulating the production of fusaric acid, which was a crucial phytotoxin in accelerating development of Fusarium wilt symptoms in banana plants. Additionally, we found that the MAP kinase FoSlt2 was required for siderophore biosynthesis under iron-depletion conditions. Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2. Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence.

No MeSH data available.


Related in: MedlinePlus