scholarly journals MoWhi2 regulates appressorium formation and pathogenicity via the MoTor signalling pathway in Magnaporthe oryzae

2021 ◽  
Author(s):  
Huanbin Shi ◽  
Shuai Meng ◽  
Jiehua Qiu ◽  
Congcong Wang ◽  
Yazhou Shu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Signalling Pathway ◽  
Appressorium Formation

scholarly journals A Feed-Forward Subnetwork Emerging from Integrated TOR- and cAMP/PKA-Signaling Architecture Reinforces Magnaporthe oryzae Appressorium Morphogenesis

2019 ◽  
Vol 32 (5) ◽  
pp. 593-607 ◽  
Author(s):  
Guangchao Sun ◽  
Xiaobo Qi ◽  
Richard A. Wilson
Keyword(s):  
Cell Cycle ◽  
Adenylate Cyclase ◽  
Magnaporthe Oryzae ◽  
Environmental Conditions ◽  
Germ Tube ◽  
Nutrient Status ◽  
Specific Cell ◽  
Appressorium Formation ◽  
G2 Arrest ◽  
Feed Forward

Appressoria are important mediators of plant–microbe interactions. In the devastating rice blast pathogen Magnaporthe oryzae, appressorial morphogenesis from germ tube tips requires activated cAMP/PKA signaling and inactivated TOR signaling (TORoff). TORoff temporarily arrests G2 at a metabolic checkpoint during the single round of mitosis that occurs following germination. G2 arrest induces autophagy and appressorium formation concomitantly, allowing reprogression of the cell cycle to G1/G0 quiescence and a single appressorial nucleus. Inappropriate TOR activation abrogates G2 arrest and inhibits cAMP/PKA signaling downstream of cPKA. This results in multiple rounds of germ tube mitosis and the loss of autophagy and appressoria formation. How cAMP/PKA signaling connects to cell cycle progression and autophagy is not known. To address this, we interrogated TOR and cAMP/PKA pathways using signaling mutants, different surface properties, and specific cell cycle inhibitors and discovered a feed-forward subnetwork arising from TOR- and cAMP/PKA-signaling integration. This adenylate cyclase-cAMP-TOR-adenylate cyclase subnetwork reinforces cAMP/PKA-dependent appressorium formation under favorable environmental conditions. Under unfavorable conditions, the subnetwork collapses, resulting in reversible cell cycle-mediated germ tube growth regardless of external nutrient status. Collectively, this work provides new molecular insights on germ tube morphogenetic decision-making in response to static and dynamic environmental conditions.

Complexity of roles and regulation of the PMK1-MAPK pathway in mycelium development, conidiation and appressorium formation in Magnaporthe oryzae

2013 ◽  
Vol 13 (5-6) ◽  
pp. 133-141 ◽  
Author(s):  
Qingchao Jin ◽  
Chanyuan Li ◽  
Youzhi Li ◽  
Jinjie Shang ◽  
Debao Li ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Mapk Pathway ◽  
Appressorium Formation

scholarly journals Bypassing Both Surface Attachment and Surface Recognition Requirements for Appressorium Formation by Overactive Ras Signaling in Magnaporthe oryzae

2014 ◽  
Vol 27 (9) ◽  
pp. 996-1004 ◽  
Author(s):  
Xiaoying Zhou ◽  
Xinhua Zhao ◽  
Chaoyang Xue ◽  
Yafeng Dai ◽  
Jin-Rong Xu
Keyword(s):  
Magnaporthe Oryzae ◽  
Pathogenic Fungi ◽  
Mitogen Activated Protein Kinase ◽  
Ras Signaling ◽  
Colletotrichum Graminicola ◽  
Appressorium Formation ◽  
Surface Attachment ◽  
Surface Recognition ◽  
Aerial Hyphae ◽  
Liquid Suspensions

Magnaporthe oryzae forms a highly specialized infection structure called an appressorium for plant penetration. In M. oryzae and many other plant-pathogenic fungi, surface attachment and surface recognition are two essential requirements for appressorium formation. Development of appressoria in the air has not been reported. In this study, we found that expression of a dominant active MoRAS2G18V allele in M. oryzae resulted in the formation of morphologically abnormal appressoria on nonconducive surfaces, in liquid suspensions, and on aerial hyphae without attachment to hard surfaces. Both the Pmk1 mitogen-activated protein kinase cascade and cAMP signaling pathways that regulate surface recognition and appressorium morphogenesis in M. oryzae were overactivated in the MoRAS2G18V transformant. In mutants deleted of PMK1 or CPKA, expression of MoRAS2G18V had no significant effects on appressorium morphogenesis. Furthermore, expression of dominant MoRAS2 in Colletotrichum graminicola and C. gloeosporioides also caused the formation of appressorium-like structures in aerial hyphae. Overall, our data indicate that MoRas2 functions upstream from both the cAMP-PKA and Pmk1 pathways and overactive Ras signaling leads to improper activation of these two pathways and appressorium formation without surface attachment in appressorium-forming pathogens.

scholarly journals The seven transmembrane domain protein MoRgs7 functions in surface perception and undergoes coronin MoCrn1-dependent endocytosis in complex with Gα subunit MoMagA to promote cAMP signaling and appressorium formation in Magnaporthe oryzae

2018 ◽  
Author(s):  
Xiao Li ◽  
Kaili Zhong ◽  
Ziyi Yin ◽  
Jiexiong Hu ◽  
Lianwei Li ◽  
...  
Keyword(s):  
G Protein ◽  
Magnaporthe Oryzae ◽  
Transmembrane Domain ◽  
Surface Hydrophobicity ◽  
Camp Signaling ◽  
Actin Binding ◽  
Rgs Proteins ◽  
Appressorium Formation ◽  
Rgs Domain ◽  
Tm Domain

AbstractRegulator of G-protein signaling (RGS) proteins primarily function as GTPase-accelerating proteins (GAPs) to promote GTP hydrolysis of Gα subunits, thereby regulating G-protein mediated signaling. RGS proteins could also contain additional domains such as GoLoco to inhibit GDP dissociation. The rice blast fungus Magnaporthe oryzae encodes eight RGS and RGS-like proteins (MoRgs1 to MoRgs8) that have shared and distinct functions in growth, appressorium formation and pathogenicity. Interestingly, MoRgs7 and MoRgs8 contain a C-terminal seven-transmembrane domain (7-TM) motif typical of G-protein coupled receptor (GPCR) proteins, in addition to the conserved RGS domain. We found that MoRgs7, together with Gα MoMagA but not MoRgs8, undergoes endocytic transport from the plasma membrane to the endosome upon sensing of surface hydrophobicity. We also found that MoRgs7 can interact with hydrophobic surfaces via a hydrophobic interaction, leading to the perception of environmental hydrophobic cues. Moreover, we found that MoRgs7-MoMagA endocytosis is regulated by actin patch-associated protein MoCrn1, linking it to cAMP signaling. Our studies provided evidence suggesting that MoRgs7 could also function in a GPCR-like manner to sense environmental signals and it, together with additional proteins of diverse functions, promotes cAMP signaling required for developmental processes underlying appressorium function and pathogenicity.Author summaryThe 7-TM domain is considered the hallmark of GPCR proteins, which activate G proteins upon ligand binding and undergo endocytosis for regeneration or recycling. Among eight RGS and RGS-like proteins of M. oryzae, MoRgs7 and MoRgs8 contain the 7-TM domain in addition to the RGS domain. We found that MoRgs7 can form hydrophobic interactions with the hydrophobic surface. This interaction is important in sensing hydrophobic cues by the fungus. We also found that, in response to surface hydrophobicity, MoRgs7 couples with Gα subunit MoMagA to undergo endocytosis leading to the activation of cAMP signaling. Moreover, we found that such an endocytic event requires functions of the actin-binding protein MoCrn1. Our results revealed MoRgs7 functions as a GPCR-like receptor protein to sense surface cues and activate signaling required for pathogenesis, providing new insights into G-protein regulatory mechanisms in this and other pathogenic fungi.

scholarly journals Magnaporthe oryzae Auxiliary Activity Protein MoAa91 Functions as Chitin-Binding Protein To Induce Appressorium Formation on Artificial Inductive Surfaces and Suppress Plant Immunity

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Ying Li ◽  
Xinyu Liu ◽  
Muxing Liu ◽  
Yang Wang ◽  
Yibin Zou ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Binding Protein ◽  
Plant Immunity ◽  
G Protein Signaling ◽  
Protein Signaling ◽  
Appressorium Formation ◽  
Protein Precursor ◽  
Content Type ◽  
Surface Recognition ◽  
Appressorium Development

ABSTRACT The appressoria that are generated by the rice blast fungus Magnaporthe oryzae in response to surface cues are important for successful colonization. Previous work showed that regulators of G-protein signaling (RGS) and RGS-like proteins play critical roles in appressorium formation. However, the mechanisms by which these proteins orchestrate surface recognition for appressorium induction remain unclear. Here, we performed comparative transcriptomic studies of ΔMorgs mutant and wild-type strains and found that M. oryzae Aa91 (MoAa91), a homolog of the auxiliary activity family 9 protein (Aa9), was required for surface recognition of M. oryzae. We found that MoAA91 was regulated by the MoMsn2 transcription factor and that its disruption resulted in defects in both appressorium formation on the artificial inductive surface and full virulence of the pathogen. We further showed that MoAa91 was secreted into the apoplast space and was capable of competing with the immune receptor chitin elicitor-binding protein precursor (CEBiP) for chitin binding, thereby suppressing chitin-induced plant immune responses. In summary, we have found that MoAa91 is a novel signaling molecule regulated by RGS and RGS-like proteins and that MoAa91 not only governs appressorium development and virulence but also functions as an effector to suppress host immunity. IMPORTANCE The rice blast fungus Magnaporthe oryzae generates infection structure appressoria in response to surface cues largely due to functions of signaling molecules, including G-proteins, regulators of G-protein signaling (RGS), mitogen-activated protein (MAP) kinase pathways, cAMP signaling, and TOR signaling pathways. M. oryzae encodes eight RGS and RGS-like proteins (MoRgs1 to MoRgs8), and MoRgs1, MoRgs3, MoRgs4, and MoRgs7 were found to be particularly important in appressorium development. To explore the mechanisms by which these proteins regulate appressorium development, we have performed a comparative in planta transcriptomic study and identified an auxiliary activity family 9 protein (Aa9) homolog that we named MoAa91. We showed that MoAa91 was secreted from appressoria and that the recombinant MoAa91 could compete with a chitin elicitor-binding protein precursor (CEBiP) for chitin binding, thereby suppressing chitin-induced plant immunity. By identifying MoAa91 as a novel signaling molecule functioning in appressorium development and an effector in suppressing host immunity, our studies revealed a novel mechanism by which RGS and RGS-like proteins regulate pathogen-host interactions.

The putative Gγ subunit gene MGG1 is required for conidiation, appressorium formation, mating and pathogenicity in Magnaporthe oryzae

2015 ◽  
Vol 61 (4) ◽  
pp. 641-651 ◽  
Author(s):  
Ya Li ◽  
Yawei Que ◽  
Yuting Liu ◽  
Xiaofeng Yue ◽  
Xiuli Meng ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Subunit Gene ◽  
Appressorium Formation

scholarly journals Pleiotropic Function of the Putative Zinc-Finger Protein MoMsn2 in Magnaporthe oryzae

2014 ◽  
Vol 27 (5) ◽  
pp. 446-460 ◽  
Author(s):  
Haifeng Zhang ◽  
Qian Zhao ◽  
Xianxian Guo ◽  
Min Guo ◽  
Zhongqiang Qi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Magnaporthe Oryzae ◽  
Stress Responses ◽  
Zinc Finger Protein ◽  
Affinity Purification ◽  
Hyphal Growth ◽  
Mitogen Activated Protein Kinase ◽  
Phenotypic Characterization ◽  
Cell Wall Biosynthesis ◽  
Appressorium Formation

The mitogen-activated protein kinase MoOsm1–mediated osmoregulation pathway plays crucial roles in stress responses, asexual and sexual development, and pathogenicity in Magnaporthe oryzae. Utilizing an affinity purification approach, we identified the putative transcriptional activator MoMsn2 as a protein that interacts with MoOsm1 in vivo. Disruption of the MoMSN2 gene resulted in defects in aerial hyphal growth, conidial production, and infection of host plants. Quantitative reverse transcription-polymerase chain reaction analysis showed that the expression of several genes involved in conidiophore formation was reduced in ΔMomsn2, suggesting that MoMsn2 might function as a transcriptional regulator of these genes. Subsequently, MoCos1 was identified as one of the MoMsn2 targets through yeast one-hybrid analysis in which MoMsn2 binds to the AGGGG and CCCCT motif of the MoCOS1 promoter region. Phenotypic characterization showed that MoMsn2 was required for appressorium formation and penetration and pathogenicity. Although the ΔMomsn2 mutant was tolerant to the cell-wall stressor Calcofluor white, it was sensitive to common osmotic stressors. Further analysis suggests that MoMsn2 is involved in the regulation of the cell-wall biosynthesis pathway. Finally, transcriptome data revealed that MoMsn2 modulates numerous genes participating in conidiation, infection, cell-wall integrity, and stress response. Collectively, our results led to a model in which MoMsn2 mediates a series of downstream genes that control aerial hyphal growth, conidiogenesis, appressorium formation, cell-wall biosynthesis, and infection and that also offer potential targets for the development of new disease management strategies.

scholarly journals PAF104, a Synthetic Peptide to Control Rice Blast Disease by Blocking Appressorium Formation in Magnaporthe oryzae

2013 ◽  
Vol 26 (12) ◽  
pp. 1407-1416 ◽  
Author(s):  
Aarón Rebollar ◽  
Belén López-García
Keyword(s):  
Magnaporthe Oryzae ◽  
Synthetic Peptide ◽  
Rice Blast ◽  
Surface Protein ◽  
Inhibitory Effect ◽  
Rice Blast Disease ◽  
Blast Disease ◽  
Appressorium Formation ◽  
Hydrophobic Surfaces

Magnaporthe oryzae is the most devastating pathogen of rice and the main cause of crop losses worldwide. The successful management of blast disease caused by this fungus is a clear necessity. The synthetic peptide PAF104 has been characterized by its inhibition of M. oryzae appressorium formation on hydrophobic surfaces. Growth and the ability of conidia to germinate was not affected by PAF104, indicating the lack of toxicity on fungal conidia. The addition of the cutin monomer 1,16-hexadecanediol does not interfere with the inhibitory effect of PAF104 on in vitro hydrophobic surfaces. On the other hand, inhibition of appressorium formation by PAF104 was nullified by the exogenous addition of cAMP. Our results suggest that PAF104 affects the Pmk1 pathway by repression of the gene expression of MoMSB2, which encodes a sensing surface protein, and the mitogen-activated protein/extracellular signal-regulated kinase kinase kinase MST11. The pathogenicity of M. oryzae was reduced after PAF104 treatment specifically blocking appressorium formation. Our results support PAF104 as a promising compound to control rice blast disease by blocking a specific target related to appressorium formation, a process essential for infection of rice leaves. Moreover, PAF104 is proposed as a lead compound to develop novel specific fungicides with improved properties.

scholarly journals PKA activity is essential for relieving the suppression of hyphal growth and appressorium formation by MoSfl1 in Magnaporthe oryzae

PLoS Genetics ◽  
2017 ◽  
Vol 13 (8) ◽  
pp. e1006954 ◽  
Author(s):  
Yang Li ◽  
Xue Zhang ◽  
Shuai Hu ◽  
Huiquan Liu ◽  
Jin-Rong Xu
Keyword(s):  
Magnaporthe Oryzae ◽  
Hyphal Growth ◽  
Appressorium Formation
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