Functional analyses of regulators of G protein signaling in Gibberella zeae.
Regulators of G protein signaling (RGS) proteins make up a highly diverse and multifunctional protein family that plays a critical role in controlling heterotrimeric G protein signaling. In this study, seven RGS genes (FgFlbA, FgFlbB, FgRgsA, FgRgsB, FgRgsB2, FgRgsC, and FgGprK) were functionally characterized in the plant pathogenic fungus, Gibberella zeae. Mutant phenotypes were observed for deletion mutants of FgRgsA and FgRgsB in vegetative growth, FgFlbB and FgRgsB in conidia morphology, FgFlbA in conidia production, FgFlbA, FgRgsB, and FgRgsC in sexual development, FgFlbA and FgRgsA in spore germination and mycotoxin production, and FgFlbA, FgRgsA, and FgRgsB in virulence. Furthermore, FgFlbA, FgRgsA, and FgRgsB acted pleiotropically, while FgFlbB and FgRgsC deletion mutants exhibited a specific defect in conidia morphology and sexual development, respectively. Amino acid substitutions in Gα subunits and overexpression of the FgFlbA gene revealed that deletion of FgFlbA and dominant active GzGPA2 mutant, gzgpa2(Q207L), had similar phenotypes in cell wall integrity, perithecia formation, mycotoxin production, and virulence, suggesting that FgFlbA may regulate asexual/sexual development, mycotoxin biosynthesis, and virulence through GzGPA2-dependent signaling in G. zeae.
Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Republic of Korea.
Ae Ran
AR
Park
Ah-Ram
AR
Cho
Jeong-Ah
JA
Seo
Kyunghun
K
Min
Hokyoung
H
Son
Jungkwan
J
Lee
Gyung Ja
GJ
Choi
Jin-Cheol
JC
Kim
Yin-Won
YW
Lee
D019943:Amino Acid Substitution; D019204:GTP-Binding Proteins / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D005874:Gibberella / Q000166:cytology* / Q000235:genetics / Q000502:physiology*; D016297:Mutagenesis, Site-Directed; D020710:RGS Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
D020710:RGS Proteins; D019204:GTP-Binding Proteins