scholarly journals Targeted Disruption of a Fungal G-Protein β Subunit Gene Results in Increased Vegetative Growth but Reduced Virulence

1997 ◽  
Vol 10 (8) ◽  
pp. 984-993 ◽  
Author(s):  
Shin Kasahara ◽  
Donald L. Nuss
Keyword(s):  
Amino Acid ◽  
G Protein ◽  
Vegetative Growth ◽  
Synthetic Medium ◽  
Cryphonectria Parasitica ◽  
Β Subunit ◽  
Subunit Gene ◽  
Targeted Disruption ◽  
Fungal Virulence ◽  
Α Subunit

Targeted disruption of two G-protein α subunit genes in the chestnut blight fungus Cryphonectria parasitica revealed roles for the Giα subunit CPG-1 in fungal reproduction, virulence, and vegetative growth. A second Gα subunit, CPG-2, was found to be dispensable for these functions. We now report the cloning and targeted disruption of a C. parasitica G-protein β subunit gene. The deduced amino acid sequence encoded by this gene, designated cpgb-1, was found to share 66.2, 65.9, and 66.7% amino acid identity with Gβ homologues from human, Drosophila, and Dictyostelium origins, respectively, but only 39.7% identity with the Saccharomyces cerevisiae Gβ homologue STE4 product. Low stringency Southern hybridization failed to detect any related Gβ subunit genes in C. parasitica. Targeted disruption of cpgb-1 resulted in several of the changes previously reported to accompany disruption of the C. parasitica Giα subunit gene cpg-1. These included very significant reductions in pigmentation, asexual sporulation, and virulence. In contrast to results obtained for Giα gene disruption, the reduction in virulence resulting from the disruption of a Gβ gene was accompanied by increased, rather than decreased, vegetative growth on synthetic medium. The relevance of these results to mechanisms of fungal virulence is considered.

scholarly journals G Protein α Subunit Genes Control Growth, Development, and Pathogenicity of Magnaporthe grisea

1997 ◽  
Vol 10 (9) ◽  
pp. 1075-1086 ◽  
Author(s):  
Shaohua Liu ◽  
Ralph A. Dean
Keyword(s):  
Neurospora Crassa ◽  
G Protein ◽  
Vegetative Growth ◽  
Magnaporthe Grisea ◽  
Cryphonectria Parasitica ◽  
Appressorium Formation ◽  
Α Subunit ◽  
Targeted Deletion ◽  
Control Growth ◽  
G Protein Α Subunit

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.

scholarly journals The maize heterotrimeric G protein β subunit controls shoot meristem development and immune responses

2019 ◽  
Vol 117 (3) ◽  
pp. 1799-1805 ◽  
Author(s):  
Qingyu Wu ◽  
Fang Xu ◽  
Lei Liu ◽  
Si Nian Char ◽  
Yezhang Ding ◽  
...  
Keyword(s):  
G Protein ◽  
Cross Talk ◽  
Normal Growth ◽  
Shoot Meristem ◽  
Β Subunit ◽  
Subunit Gene ◽  
Α Subunit ◽  
Knock Out ◽  
Meristem Size ◽  
Meristem Development

Heterotrimeric G proteins are important transducers of receptor signaling, functioning in plants with CLAVATA receptors in controlling shoot meristem size and with pathogen-associated molecular pattern receptors in basal immunity. However, whether specific members of the heterotrimeric complex potentiate cross-talk between development and defense, and the extent to which these functions are conserved across species, have not yet been addressed. Here we used CRISPR/Cas9 to knock out the maize G protein β subunit gene (Gβ) and found that the mutants are lethal, differing from those in Arabidopsis, in which homologous mutants have normal growth and fertility. We show that lethality is caused not by a specific developmental arrest, but by autoimmunity. We used a genetic diversity screen to suppress the lethal Gβ phenotype and also identified a maize Gβ allele with weak autoimmune responses but strong development phenotypes. Using these tools, we show that Gβ controls meristem size in maize, acting epistatically with G protein α subunit gene (Gα), suggesting that Gβ and Gα function in a common signaling complex. Furthermore, we used an association study to show that natural variation in Gβ influences maize kernel row number, an important agronomic trait. Our results demonstrate the dual role of Gβ in immunity and development in a cereal crop and suggest that it functions in cross-talk between these competing signaling networks. Therefore, modification of Gβ has the potential to optimize the trade-off between growth and defense signaling to improve agronomic production.

Targeted disruption of a G protein α subunit gene results in reduced growth and pathogenicity in Rhizoctonia solani

2007 ◽  
Vol 24 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Kanlayani Charoensopharat ◽  
Nuntipa Aukkanit ◽  
Sudarat Thanonkeo ◽  
Weerasak Saksirirat ◽  
Pornthap Thanonkeo ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
G Protein ◽  
Subunit Gene ◽  
Targeted Disruption ◽  
Α Subunit ◽  
G Protein Α Subunit

Targeted disruption of a G protein α subunit gene results in reduced pathogenicity in Fusarium oxysporum

2002 ◽  
Vol 41 (6) ◽  
pp. 407-413 ◽  
Author(s):  
Sona Jain ◽  
Kouichi Akiyama ◽  
Kenjiro Mae ◽  
Tomizo Ohguchi ◽  
Renkichi Takata
Keyword(s):  
Fusarium Oxysporum ◽  
G Protein ◽  
Subunit Gene ◽  
Targeted Disruption ◽  
Α Subunit ◽  
G Protein Α Subunit

Cloning and Analyzing of G-protein β-Subunit Gene in Rhizoctonia solani Causing Soybean Sharp Eyespot

2009 ◽  
Vol 35 (2) ◽  
pp. 370-374
Author(s):  
Bing-Tian MA ◽  
Guang-Lin QU ◽  
Wen-Juan HUANG ◽  
Yu-Fan LIN ◽  
Shi-Gui LI
Keyword(s):  
Rhizoctonia Solani ◽  
G Protein ◽  
Β Subunit ◽  
Subunit Gene ◽  
Sharp Eyespot

Cloning and Characterization of a G Protein β Subunit Gene Responsive to Plant Hormones and Abiotic Stresses in Brassica napus

2010 ◽  
Vol 28 (3) ◽  
pp. 450-459 ◽  
Author(s):  
Yong Gao ◽  
Yun Zhao ◽  
Tingting Li ◽  
Caixia Ren ◽  
Yang Liu ◽  
...  
Keyword(s):  
Brassica Napus ◽  
G Protein ◽  
Plant Hormones ◽  
Abiotic Stresses ◽  
Β Subunit ◽  
Subunit Gene

scholarly journals A G-Protein β Subunit Required for Sexual and Vegetative Development and Maintenance of Normal Gα Protein Levels in Neurospora crassa

2002 ◽  
Vol 1 (3) ◽  
pp. 378-390 ◽  
Author(s):  
Qi Yang ◽  
Sheven I. Poole ◽  
Katherine A. Borkovich
Keyword(s):  
Neurospora Crassa ◽  
G Protein ◽  
Single Gene ◽  
Cryphonectria Parasitica ◽  
Female Sterility ◽  
Specific Gene ◽  
Extension Rate ◽  
Β Subunit ◽  
Submerged Cultures ◽  
Protein Levels

ABSTRACT The genome of the filamentous fungus Neurospora crassa contains a single gene encoding a heterotrimeric G-protein β subunit, gnb-1. The predicted GNB-1 protein sequence is most identical to Gβ proteins from the filamentous fungi Cryphonectria parasitica and Aspergillus nidulans. N. crassa GNB-1 is also 65% identical to the human GNB-1 protein but only 38 and 45% identical to Gβ proteins from budding and fission yeasts. Previous studies in animal and fungal systems have elucidated phenotypes of Gβ null mutants, but little is known about the effects of Gβ loss on Gα levels. In this study, we analyzed a gnb-1 deletion mutant for cellular phenotypes and levels of the three Gα proteins. Δgnb-1 strains are female-sterile, with production of aberrant fertilized reproductive structures. Δgnb-1 strains conidiate more profusely and have altered mass on solid medium. Loss of gnb-1 leads to inappropriate conidiation and expression of a conidiation-specific gene during growth in submerged culture. Intracellular cyclic AMP levels are reduced by 60% in vegetative plate cultures of Δgnb-1 mutants. Loss of gnb-1 leads to lower levels of the three Gα proteins under a variety of conditions. Analysis of transcript levels for the gna-1 and gna-2 Gα genes in submerged cultures indicates that regulation of Gα protein levels by gnb-1 is posttranscriptional. The results suggest that GNB-1 directly regulates apical extension rate and mass accumulation. In contrast, many other Δgnb-1 phenotypes, including female sterility and defective conidiation, can be explained by altered levels of the three N. crassa Gα proteins.

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