Evidence that the Appressorial Development in Barley Powdery Mildew is Controlled by MAP Kinase Activity in Conjunction with the cAMP Pathway
MetadataShow full item record
A copy of this item may be available from Professor Richard Oliver
Development of the barley powdery mildew fungus involves the sequential formation of a primary germ tube, an appressorial germ tube, and an appressorium. Previously, we have shown that the cAMP pathway controls the emergence of the two germ tubes. Following identification of two MAP kinase genes in an EST database from developing conidia we studied the role of the MAP kinase pathway and its interaction with the cAMP pathway. Fungal MAP kinase activity increased rapidly during mildew development, reaching a maximum between 2 and 8 h after inoculation. Sphingosine or PAF-16, activators of the MAP kinase pathway, increased activity and appressorial development whilst an inhibitor, PD 98059, decreased both. Studies on the interaction between the cAMP and MAPK pathways revealed that several effectors of the MAPK pathway had no effect on cAMP levels. However upstream effectors of the cAMP pathway, such as cholera toxin and pertussis toxin (activators of Gα proteins) increased MAPK activities whereas downstream effectors such as forskolin (adenylyl cyclase activator) or H89 (PKA inhibitor) had no effect. Combined application of forskolin and sphingosine produced a rise in appressorial germ tube and appressorial formation higher than when either pathway was stimulated individually. These results suggest that the two pathways cooperate in appressorial development.
Showing items related by title, author, creator and subject.
Evidence that the cAMP Pathway Controls Emergence of Both Primary and Appressorial Germ Tubes of Barley Powdery MildewKinane, J.; Dalvin, S.; Bindslev, L.; Hall, A.; Gurr, S.; Oliver, Richard (2000)Development of conidia of barley powdery mildew involves the formation of a primary germ tube (PGT), an appressorial germ tube (AGT), and an appressorium. Previously, it was found that cyclic AMP (cAMP) was involved in ...
Involvement of cAMP and Protein Kinase A in Conidial Differentiation by Erysiphe graminis f. sp. hordeiHall, A.; Bindslev, L.; Rouster, J.; Rasmussen, S.; Oliver, Richard; Gurr, S. (1999)Erysiphe graminis f. sp. hordei, the causal agent of barley powdery mildew, is an obligate biotroph. On arrival on the host, a primary germ tube (PGT) emerges from the conidium. An appressorial germ tube (AGT) then appears, ...
Transcript Profiling in the Barley Mildew Pathogen Blumeria graminis by Serial Analysis of Gene Expression (SAGE)Thomas, S.; Glaring, M.; Rasmussen, S.; Kinane, J.; Oliver, Richard (2002)The fungal pathogen Blumeria graminis f. sp. hordei develops on the barley leaf via distinct, morphologically well-defined stages. After landing on a host plant, the conidia rapidly germinate to form a primary germ tube. ...