Cuticular waxes relieve self-inhibition of germination and appressorium formation by the conidia ofMagnaporthe grisea

Hegde, Yashoda R.; Kolattukudy, Pappachan E.

doi:10.1006/pmpp.1997.0105

Cited by 78 publications

(57 citation statements)

References 13 publications

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“…The spores of plant pathogenic fungi such as Magnaporthe grisea and Colletotrichum spp. are able to germinate in the absence of nutrients (25,54). Although the spore germination of G. zeae has been studied (21), at least two factors could play a role in retarding spore germination in the ⌬GzSNF1 mutants.…”

Section: Discussionmentioning

confidence: 99%

GzSNF1Is Required for Normal Sexual and Asexual Development in the AscomyceteGibberella zeae

Lee

et al. 2009

Eukaryot Cell

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The sucrose nonfermenting 1 (SNF1) protein kinase of yeast plays a central role in the transcription of glucose-repressible genes in response to glucose starvation. In this study, we deleted an ortholog of SNF1 from Gibberella zeae to characterize its functions by using a gene replacement strategy. The mycelial growth of deletion mutants (⌬GzSNF1) was reduced by 21 to 74% on diverse carbon sources. The virulence of ⌬GzSNF1 mutants on barley decreased, and the expression of genes encoding cell-wall-degrading enzymes was reduced. The most distinct phenotypic changes were in sexual and asexual development. ⌬GzSNF1 mutants produced 30% fewer perithecia, which matured more slowly, and asci that contained one to eight abnormally shaped ascospores. Mutants in which only the GzSNF1 catalytic domain was deleted had the same phenotype changes as the ⌬GzSNF1 strains, but the phenotype was less extreme in the mutants with the regulatory domain deleted. In outcrosses between the ⌬GzSNF1 mutants, each perithecium contained ϳ70% of the abnormal ascospores, and ϳ50% of the asci showed unexpected segregation patterns in a single locus tested. The asexual spores of the ⌬GzSNF1 mutants were shorter and had fewer septa than those of the wild-type strain. The germination and nucleation of both ascospores and conidia were delayed in ⌬GzSNF1 mutants in comparison with those of the wild-type strain. GzSNF1 expression and localization depended on the developmental stage of the fungus. These results suggest that GzSNF1 is critical for normal sexual and asexual development in addition to virulence and the utilization of alternative carbon sources.

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Section: Discussionmentioning

confidence: 99%

GzSNF1Is Required for Normal Sexual and Asexual Development in the AscomyceteGibberella zeae

Lee

et al. 2009

Eukaryot Cell

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“…The cuticle permeability modification in these transgenic plants could be responsible for a less efficient perception of the fungal elicitors, delaying the activation of the defense responses. Furthermore, it has been shown that leaf or fruit waxes could contain active components that induce germination and appressorium formation by fungal pathogens (Podila et al, 1993;Hegde and Kolattukudy, 1997;Reisige et al, 2006). Therefore, VLC alkanes accumulated on the CER1ox leaf surface could act as components activating the development of the fungus or could deeply perturb the hydrophobic properties of the leaf cuticle and allow better fungus propagation.…”

Section: Role Of Wax Vlc Alkanes In Biotic Stress Responsementioning

confidence: 99%

Overexpression of ArabidopsisECERIFERUM1Promotes Wax Very-Long-Chain Alkane Biosynthesis and Influences Plant Response to Biotic and Abiotic Stresses

et al. 2011

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Land plant aerial organs are covered by a hydrophobic layer called the cuticle that serves as a waterproof barrier protecting plants against desiccation, ultraviolet radiation, and pathogens. Cuticle consists of a cutin matrix as well as cuticular waxes in which very-long-chain (VLC) alkanes are the major components, representing up to 70% of the total wax content in Arabidopsis (Arabidopsis thaliana) leaves. However, despite its major involvement in cuticle formation, the alkane-forming pathway is still largely unknown. To address this deficiency, we report here the characterization of the Arabidopsis ECERIFERUM1 (CER1) gene predicted to encode an enzyme involved in alkane biosynthesis. Analysis of CER1 expression showed that CER1 is specifically expressed in the epidermis of aerial organs and coexpressed with other genes of the alkane-forming pathway. Modification of CER1 expression in transgenic plants specifically affects VLC alkane biosynthesis: waxes of TDNA insertional mutant alleles are devoid of VLC alkanes and derivatives, whereas CER1 overexpression dramatically increases the production of the odd-carbon-numbered alkanes together with a substantial accumulation of iso-branched alkanes. We also showed that CER1 expression is induced by osmotic stresses and regulated by abscisic acid. Furthermore, CER1-overexpressing plants showed reduced cuticle permeability together with reduced soil water deficit susceptibility. However, CER1 overexpression increased susceptibility to bacterial and fungal pathogens. Taken together, these results demonstrate that CER1 controls alkane biosynthesis and is highly linked to responses to biotic and abiotic stresses.

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“…Besides fungal penetration of the cuticular layer during initial stages of infection, cutinases have been suggested to have a role in spore attachment (Deising et al, 1992) and in carbon acquisition for saprophytic growth (Köller and Parker, 1989). Cutinases secreted by the fungus may partially break down the plant cuticle to produce cutin monomers, which have been shown not only to induce the expression of cutinase (Lin and Kolattukudy, 1978) but to trigger conidial germination and differentiation of appressoria (Gilbert et al, 1996;Hegde and Kolattukudy, 1997). Thus, cutinases may have a role in surface signalling that is crucial for the differentiation of essential infection structure and expression of pathogenicity factors.…”

Section: Introductionmentioning

confidence: 99%

Evolution of the cutinase gene family: Evidence for lateral gene transfer of a candidate Phytophthora virulence factor

Belbahri¹,

Calmin²,

Mauch³

et al. 2008

Gene

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Lateral gene transfer (LGT) can facilitate the acquisition of new functions in recipient lineages, which may enable them to colonize new environments. Several recent publications have shown that gene transfer between prokaryotes and eukaryotes occurs with appreciable frequency. Here we present a study of interdomain gene transfer of cutinases -well documented virulence factors in fungi -between eukaryotic plant pathogens Phytophthora species and prokaryotic bacterial lineages. Two putative cutinase genes were cloned from Phytophthora brassicae and Northern blotting experiments showed that these genes are expressed early during the infection of the host Arabidopsis thaliana and induced during cyst germination of the pathogen. Analysis of the gene organisation of this gene family in Phytophthora ramorum and P. sojae showed three and ten copies in tight succession within a region of 5 and 25 kb, respectively, probably indicating a recent expansion in Phytophthora lineages by gene duplications. Bioinformatic analyses identified orthologues only in three genera of Actinobacteria, and in two distantly related eukaryotic groups: oomycetes and fungi. Together with phylogenetic analyses this limited distribution of the gene in the tree of life strongly support a scenario where cutinase genes originated after the origin of land plants in a microbial lineage living in proximity of plants and subsequently were transferred between distantly related plant-degrading microbes. More precisely, a cutinase gene was likely acquired by an ancestor of P. brassicae, P. sojae, P. infestans and P. ramorum, possibly from an actinobacterial source, suggesting that gene transfer might be an important mechanism in the evolution of their virulence. These findings could indeed provide an interesting model system to study acquisition of virulence factors in these important plant pathogens.

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Cuticular waxes relieve self-inhibition of germination and appressorium formation by the conidia ofMagnaporthe grisea

Cited by 78 publications

References 13 publications

GzSNF1Is Required for Normal Sexual and Asexual Development in the AscomyceteGibberella zeae

GzSNF1Is Required for Normal Sexual and Asexual Development in the AscomyceteGibberella zeae

Overexpression of ArabidopsisECERIFERUM1Promotes Wax Very-Long-Chain Alkane Biosynthesis and Influences Plant Response to Biotic and Abiotic Stresses

Evolution of the cutinase gene family: Evidence for lateral gene transfer of a candidate Phytophthora virulence factor

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