Linked Life Data

15141959

Source:http://linkedlifedata.com/resource/pubmed/id/15141959

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-5-14
pubmed:databankReference
pubmed:abstractText
In the rice blast fungus Magnaporthe grisea, the Pmk1 mitogen-activated protein (MAP) kinase is essential for appressorium formation and infectious growth. PMK1 is homologous to yeast Fus3 and Kss1 MAP kinases that are known to be regulated by the Ste20 PAK kinase for activating the pheromone response and filamentation pathways. In this study, we isolated and characterized two PAK genes, CHM1 and MST20, in M. grisea. Mutants disrupted in MST20 were reduced in aerial hyphae growth and conidiation, but normal in growth rate, appressorium formation, penetration, and plant infection. In chm1 deletion mutants, growth, conidiation, and appressorium formation were reduced significantly. Even though appressoria formed by chm1 mutants were defective in penetration, chm1 mutants were able to grow invasively on rice leaves and colonize through wounds. The chm1 mutants were altered in conidiogenesis and produced conidia with abnormal morphology. Hyphae of chm1 mutants had normal septation, but the length of hyphal compartments was reduced. On nutritionally poor oatmeal agar, chm1 mutants were unstable and produced sectors that differed from original chm1 mutants in growth rate, conidiation, or colony morphology. However, none of the monoconidial cultures derived from these spontaneous sectors were normal in appressorial penetration and fungal pathogenesis. These data suggest that MST20 is dispensable for plant infection in M. grisea, but CHM1 plays a critical role in appressorium formation and penetration. Both mst20 and chm1 deletion mutants were phenotypically different from the pmk1 mutant that is defective in appressorium formation and infectious hyphae growth. It is likely that MST20 and CHM1 individually play no critical role in activating the PMK1 MAP kinase pathway during appressorium formation and infectious hyphae growth. However, CHM1 appears to be essential for appressorial penetration and CHM1 and MST20 may have redundant functions in M. grisea.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0894-0282
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
547-56
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Two PAK kinase genes, CHM1 and MST20, have distinct functions in Magnaporthe grisea.
pubmed:affiliation
Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.