Colletotrichum fructicola STE50 is required for vegetative growth, asexual reproduction, appressorium formation, pathogenicity and the response to external stress

2019 ◽  
Vol 102 (2) ◽  
pp. 335-342
Author(s):  
Yan-ying Chen ◽  
Jun-ang Liu ◽  
Shi-qiang Jiang ◽  
He Li ◽  
Guo-ying Zhou
mBio ◽  
2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Zheng Wang ◽  
Cristina Miguel-Rojas ◽  
Francesc Lopez-Giraldez ◽  
Oded Yarden ◽  
Frances Trail ◽  
...  

ABSTRACTFungal spores germinate and undergo vegetative growth, leading to either asexual or sexual reproductive dispersal. Previous research has indicated that among developmental regulatory genes, expression is conserved across nutritional environments, whereas pathways for carbon and nitrogen metabolism appear highly responsive—perhaps to accommodate differential nutritive processing. To comprehensively investigate conidial germination and the adaptive life history decision-making underlying these two modes of reproduction, we profiled transcription ofNeurospora crassagerminating on two media: synthetic Bird medium, designed to promote asexual reproduction; and a natural maple sap medium, on which both asexual reproduction and sexual reproduction manifest. A later start to germination but faster development was observed on synthetic medium. Metabolic genes exhibited altered expression in response to nutrients—at least 34% of the genes in the genome were significantly downregulated during the first two stages of conidial germination on synthetic medium. Knockouts of genes exhibiting differential expression across development altered germination and growth rates, as well as in one case causing abnormal germination. A consensus Bayesian network of these genes indicated especially tight integration of environmental sensing, asexual and sexual development, and nitrogen metabolism on a natural medium, suggesting that in natural environments, a more dynamic and tentative balance of asexual and sexual development may be typical ofN. crassacolonies.IMPORTANCEOne of the most remarkable successes of life is its ability to flourish in response to temporally and spatially varying environments. Fungi occupy diverse ecosystems, and their sensitivity to these environmental changes often drives major fungal life history decisions, including the major switch from vegetative growth to asexual or sexual reproduction. Spore germination comprises the first and simplest stage of vegetative growth. We examined the dependence of this early life history on the nutritional environment using genome-wide transcriptomics. We demonstrated that for developmental regulatory genes, expression was generally conserved across nutritional environments, whereas metabolic gene expression was highly labile. The level of activation of developmental genes did depend on current nutrient conditions, as did the modularity of metabolic and developmental response network interactions. This knowledge is critical to the development of future technologies that could manipulate fungal growth for medical, agricultural, or industrial purposes.


1997 ◽  
Vol 10 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
Shaohua Liu ◽  
Ralph A. Dean

Three G protein α subunit genes have been cloned and characterized from Magnaporthe grisea: magA is very similar to CPG-2 of Cryphonectria parasitica; magB is virtually identical to CPG-1 of Cryphonectria parasitica, to gna1 of Neurospora crassa, and to fadA of Emericella nidulans; and magC is most similar to gna2 of Neurospora crassa. Homologous recombination resulting in targeted deletion of magA had no effect on vegetative growth, conidiation, or appressorium formation. Deletion of magC reduced conidiation, but did not affect vegetative growth or appressorium formation. However, disruption of magB significantly reduced vegetative growth, conidiation, and appressorium formation. magB¯ transformants, unlike magA¯ and magC¯ transformants, exhibited a reduced ability to infect and colonize susceptible rice leaves. G protein α subunit genes are required for M. grisea mating. magB¯ transformants failed to form perithecia, whereas magA¯ and magC¯ transformants did not produce mature asci. These results suggest that G protein α subunit genes are involved in signal transduction pathways in M. grisea that control vegetative growth, conidiation, conidium attachment, appressorium formation, mating, and pathogenicity.


1971 ◽  
Vol 17 (11) ◽  
pp. 1477-1479
Author(s):  
G. E. Harman ◽  
A. A. Khan ◽  
R. E. Drury

It has been reported that fungi are not affected morphologically by morphactins. We found, however, that levels of perithecial formation by Nectria haematococca and pycnidial formation by Ascochyta pisi were strikingly lowered by concentrations of morphactin not inhibiting or only slightly inhibiting vegetative growth. Photo- or geo-tropism of Phycomyces blakesleeanus was not affected, and there was no evidence for interference by morphactin in the light reactions stimulating perithecial production by Nectria haematococca.


mBio ◽  
2021 ◽  
Author(s):  
Yiran Ren ◽  
Chi Zhang ◽  
Ziqing Chen ◽  
Ling Lu

A precisely timed switch between vegetative hyphal growth and asexual development is a crucial process for the filamentous fungal long-term survival, dissemination, biomass production, and virulence. However, under the submerged culture condition, filamentous fungi would undergo constant vegetative growth whereas asexual conidiation rarely occurs.


Microbiology ◽  
2021 ◽  
Author(s):  
Hiroshi Yoshida ◽  
Chihiro Tanaka

l-Arabinose, a major constituent pentose of plant cell-wall polysaccharides, has been suggested to be a less preferred carbon source for fungi but to be a potential signalling molecule that can cause distinct genome-wide transcriptional changes in fungal cells. Here, we explore the possibility that this unique pentose influences the morphological characteristics of the phytopathogenic fungus Bipolaris maydis strain HITO7711. When grown on plate media under different sugar conditions, the mycelial dry weight of cultures on l-arabinose was as low as that with no sugar, suggesting that l-arabinose does not substantially contribute to vegetative growth. However, the intensity of conidiation on l-arabinose was comparable to or even higher than that on d-glucose and on d-xylose, in contrast to the poor conidiation under the no-sugar condition. To explore the physiological basis of the passive growth and active conidiation on l-arabinose, we next investigated cellular responses of the fungus to these sugar conditions. Transcriptional analysis of genes related to carbohydrate metabolism showed that l-arabinose stimulates carbohydrate utilization through the hexose monophosphate shunt (HMP shunt), a catabolic pathway parallel to glycolysis and which participates in the generation of the reducing agent NADPH (the reduced form of nicotinamide adenine dinucleotide phosphate). Then, the HMP shunt was impaired by disrupting the related gene BmZwf1, which encodes glucose-6-phosphate dehydrogenase in this fungus. The resulting mutants on l-arabinose showed remarkably decreased conidiation, but a conversely increased mycelial dry weight compared with the wild-type. Our study demonstrates that l-arabinose acts to enhance resource allocation to asexual reproduction in B. maydis HITO7711 at the cost of vegetative growth, and suggests that this is mediated by the concomitant stimulation of the HMP shunt.


2021 ◽  
Author(s):  
Yingyao Liu ◽  
Martin Pagac ◽  
Fan Yang ◽  
Rajesh Narhari Patkar ◽  
Naweed I Naqvi

A key question that has remained unanswered is how pathogenic fungi switch from vegetative growth to infection-related morphogenesis during a disease cycle. Here, we identify a fungal oxylipin analogous to the well-known phytohormone jasmonic acid, as the principal morphogenesis signal responsible for such a developmental switch to pathogenicity in the rice-blast fungus Magnaporthe oryzae. We explored the molecular function(s) of such intrinsic jasmonic acid during pathogenic differentiation in M. oryzae via OPR1, which encodes a 12-Oxo-phytodienoic Acid Reductase essential for its biosynthesis. Loss of OPR1 led to prolonged vegetative growth, and a delayed initiation and improper development of infection structures in M. oryzae, reminiscent of phenotypes observed in mutants (e.g. pth11Δ and cpkAΔ) that are compromised for cyclic AMP signaling. Genetic- or chemical-complementation completely restored proper germ tube growth and appressorium formation in opr1Δ. Liquid chromatography mass spectrometry-based quantification revealed increased OPDA accumulation and a significant decrease in JA levels in the opr1Δ. Most interestingly, exogenous jasmonic acid also restored appressorium formation in the pth11Δ mutant that lacks G protein/cyclic AMP signaling. Epistasis analysis placed fungal jasmonate upstream of the cyclic AMP signaling in rice blast. Lastly, we show that intrinsic jasmonate orchestrates the cessation of vegetative phase and initiates pathogenic development via a regulatory interaction with the cyclic AMP cascade and redox signaling in rice blast.


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