Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene ex-pression profiles of appressorium development provides insight into the molecular basis of pathogenicity and...Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene ex-pression profiles of appressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST (expressed sequence tag) database of M. grisea strain Y34 was constructed and used to profile the gene expression patterns at mycelium and appressorium maturation stages. Compared with mycelia, 55 up-regulated and 22 down-regulated genes were identified in mature appressoria. Among 77 genes, 16 genes showed no similarity to the genome sequences of M. grisea. A novel homologue of peptidyl-prolyl cis-trans isomerase was found to be expressed at low-level in mature appressoria of M. grisea. The results indicated that the genes such as pyruvate car-boxylase, phospholipid metabolism-related protein and glyceraldehyde 3-phosphate dehydrogenase involved in gluconeogenesis, lipid metabolism and glycolysis, showed differential expression in mature appressoria. Furthermore, genes such as PTH11, beta subunit of G protein and SGT1 involved in cell signalling, were expressed differentially in mature appressoria. Northern blot analysis was used to confirm the cDNA array results.展开更多
Fungi have evolved diverse strategies to acquire nutrients as endophytes,saprobes,symbionts,or pathogens.Appressoria have been intensively studied due to their importance in attaching and breaching the host surface.Th...Fungi have evolved diverse strategies to acquire nutrients as endophytes,saprobes,symbionts,or pathogens.Appressoria have been intensively studied due to their importance in attaching and breaching the host surface.These specialized infection structures have evolved into various morpho-types:proto-appressoria,hyaline appressoria,melanized(dark)appressoria,and compound appressoria.In this review,we discuss the differences in the formation,differentiation,and function of appres-soria among fungi with diverse life strategies.Using DNA sequence information,LSU,5.8S,SSU and rpb2 gene fragments,we reconstructed the ancestral states for appressorial types in the main phyla of fungi and fungus-like organisms and found that the hyaline appressoria was the most ancestral form.Our analysis estimated proto-appressoria diversification during the Mesozoic period(92-239 million years ago),however,its origin remains inconclusive.Our data suggest that these hyaline appressoria diversified into melanized or compound appressoria,with evidence of adaptive radiation.展开更多
基金Project (No. 2002BA711A15) supported by the National Hi-Tech Research and Development Program (863) of China
文摘Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene ex-pression profiles of appressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST (expressed sequence tag) database of M. grisea strain Y34 was constructed and used to profile the gene expression patterns at mycelium and appressorium maturation stages. Compared with mycelia, 55 up-regulated and 22 down-regulated genes were identified in mature appressoria. Among 77 genes, 16 genes showed no similarity to the genome sequences of M. grisea. A novel homologue of peptidyl-prolyl cis-trans isomerase was found to be expressed at low-level in mature appressoria of M. grisea. The results indicated that the genes such as pyruvate car-boxylase, phospholipid metabolism-related protein and glyceraldehyde 3-phosphate dehydrogenase involved in gluconeogenesis, lipid metabolism and glycolysis, showed differential expression in mature appressoria. Furthermore, genes such as PTH11, beta subunit of G protein and SGT1 involved in cell signalling, were expressed differentially in mature appressoria. Northern blot analysis was used to confirm the cDNA array results.
文摘Fungi have evolved diverse strategies to acquire nutrients as endophytes,saprobes,symbionts,or pathogens.Appressoria have been intensively studied due to their importance in attaching and breaching the host surface.These specialized infection structures have evolved into various morpho-types:proto-appressoria,hyaline appressoria,melanized(dark)appressoria,and compound appressoria.In this review,we discuss the differences in the formation,differentiation,and function of appres-soria among fungi with diverse life strategies.Using DNA sequence information,LSU,5.8S,SSU and rpb2 gene fragments,we reconstructed the ancestral states for appressorial types in the main phyla of fungi and fungus-like organisms and found that the hyaline appressoria was the most ancestral form.Our analysis estimated proto-appressoria diversification during the Mesozoic period(92-239 million years ago),however,its origin remains inconclusive.Our data suggest that these hyaline appressoria diversified into melanized or compound appressoria,with evidence of adaptive radiation.
