| regulation of stomatal tropism and infection by light in cercospora zeae-maydis: evidence for coordinated host/pathogen responses to photoperiod? | cercospora zeae-maydis causes gray leaf spot of maize, which has become one of the most widespread and destructive diseases of maize in the world. c. zeae-maydis infects leaves through stomata, which is predicated on the ability of the pathogen to perceive stomata and reorient growth accordingly. in this study, the discovery that light was required for c. zeae-maydis to perceive stomata and infect leaves led to the identification of crp1, a gene encoding a putative blue-light photoreceptor homol ... | 2011 | 21829344 |
| mapping and validation of quantitative trait loci for resistance to cercospora zeae-maydis infection in tropical maize (zea mays l.). | breeding for resistance to gray leaf spot, caused by cercospora zeae-maydis (cz) is paramount for many maize environments, in particular under warm and humid growing conditions. in this study, we mapped and characterized quantitative trait loci (qtl) involved in the resistance of maize against cz. we confirmed the impact of the qtl on disease severity using near-isogenic lines (nils), and estimated their effects on three major agronomic traits using their respective near isogenic hybrids (nihs), ... | 2009 | 18989654 |
| analyses of expressed sequence tags from the maize foliar pathogen cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth. | the ascomycete fungus cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the western hemisphere. despite its impact on maize production, little is known about the regulation of pathogenesis in c. zeae-maydis at the molecular level. the objectives of this study were to generate a collection of expressed sequence tags (ests) from c. zeae-maydis and evaluate their expression during vegetative, infectious, and reproductive growth. | 2008 | 18983654 |
| sibling species of cercospora associated with gray leaf spot of maize. | abstract monoconidial isolates of the fungus causing gray leaf spot of maize were obtained from diseased leaves collected throughout the united states and analyzed for genetic variability at 111 amplified fragment length polymorphism (aflp) loci. cluster analysis revealed two very distinct groups of cercospora zeae-maydis isolates. both groups were found to be relatively uniform internally with an average genetic similarity among isolates of approximately 93 and 94%, respectively. the groups wer ... | 1998 | 18944828 |
| a model-based approach to preplanting risk assessment for gray leaf spot of maize. | abstract risk assessment models for gray leaf spot of maize, caused by cercospora zeae-maydis, were developed using preplanting site and maize genotype data as predictors. disease severity at the dough/dent plant growth stage was categorized into classes and used as the response variable. logistic regression and classification and regression tree (cart) modeling approaches were used to predict severity classes as a function of planting date (pd), amount of maize soil surface residue (sr), croppi ... | 2004 | 18943706 |
| probabilities for profitable fungicide use against gray leaf spot in hybrid maize. | abstract gray leaf spot, caused by the fungus cercospora zeae-maydis, causes considerable yield losses in hybrid maize grown in the north-central united states and elsewhere. nonchemical management tactics have not adequately prevented these losses. the probability of profitably using fungicide application as a management tool for gray leaf spot was evaluated in 10 field experiments under conditions of natural inoculum in iowa. gray leaf spot severity in untreated control plots ranged from 2.6 t ... | 2001 | 18943592 |
| heritability and components of resistance to cercospora zeae-maydis derived from maize inbred vo613y. | abstract gray leaf spot (gls), caused by the fungus cercospora zeae-maydis, is one of the most important foliar diseases of maize. this study was undertaken to estimate heritability of c. zeae-maydis resistance and examine the relationship between previously identified resistance loci and certain components of resistance including incubation period, lesion number, and maximum lesion length. partially inbred progenies arising from hybridization between maize inbred lines vo613y (high level of par ... | 2006 | 18943176 |
| microcycle conidiation in cercospora zeae-maydis. | abstract conidia of cercospora zeae-maydis are the primary inoculum causing gray leaf spot of maize. on nutrient-deficient substrates, but not on water on the leaf surface, conidia germinate and develop secondary conidia on conidiophores produced from germ tubes or conidial cells. a population of conidia increases its numbers more than twofold by 2 days on the surface of a water droplet and by fourfold on trichomes. this microcycle conidiation is suppressed by hydrogen peroxide and ammonium comp ... | 2003 | 18943134 |
| regression and artificial neural network modeling for the prediction of gray leaf spot of maize. | abstract regression and artificial neural network (ann) modeling approaches were combined to develop models to predict the severity of gray leaf spot of maize, caused by cercospora zeae-maydis. in all, 329 cases consisting of environmental, cultural, and location-specific variables were collected for field plots in iowa between 1998 and 2002. disease severity on the ear leaf at the dough to dent plant growth stage was used as the response variable. correlation and regression analyses were perfor ... | 2005 | 18943041 |
| phylogenetic analysis of cercospora and mycosphaerella based on the internal transcribed spacer region of ribosomal dna. | abstract most of the 3,000 named species in the genus cercospora have no known sexual stage, although a mycosphaerella teleomorph has been identified for a few. mycosphaerella is an extremely large and important genus of plant pathogens, with more than 1,800 named species and at least 43 associated anamorph genera. the goal of this research was to perform a large-scale phylogenetic analysis to test hypotheses about the past evolutionary history of cercospora and mycosphaerella. based on the phyl ... | 2001 | 18942994 |
| phl1 of cercospora zeae-maydis encodes a member of the photolyase/cryptochrome family involved in uv protection and fungal development. | dna photolyases harvest light energy to repair genomic lesions induced by uv irradiation, whereas cryptochromes, presumptive descendants of 6-4 dna photolyases, have evolved in plants and animals as blue-light photoreceptors that function exclusively in signal transduction. orthologs of 6-4 photolyases are predicted to exist in the genomes of some filamentous fungi, but their function is unknown. in this study, we identified two putative photolyase-encoding genes in the maize foliar pathogen cer ... | 2008 | 18682297 |
| species of cercospora associated with grey leaf spot of maize. | grey leaf spot is a serious yield-reducing disease of maize (zea mays) in many parts of the world where this crop is cultivated. the causal organism associated with the disease is cercospora zeae-maydis. two potential sibling species have been recognized as groups i and ii. the dna sequences for the internal transcribed spacers (its1 & its2), the 5.8s rrna gene, elongation factor 1-alpha, histone h3, actin and calmodulin gene regions suggest that groups i and ii are two distinct species. further ... | 2006 | 18490979 |
| malazy, a degenerate, species-specific transposable element in cercospora zeae-maydis. | two fungal pathogens, cercospora zeae-maydis groups i and ii, cause gray leaf spot of maize. during the sequencing of a cosmid library from c. zeae-maydis group i, we discovered a sequence with high similarity to maggy, a transposable element from magnaporthe grisea. the element from c. zeae-maydis, named malazy, contained 194-base-pair terminal repeats and sequences with high similarity to reverse transcriptase and integrase, components of the pol gene in the gypsy-like retrotransposons in fung ... | 2005 | 16396343 |
| czk3, a map kinase kinase kinase homolog in cercospora zeae-maydis, regulates cercosporin biosynthesis, fungal development, and pathogenesis. | the fungus cercospora zeae-maydis causes gray leaf spot of maize and produces cercosporin, a photosensitizing perylenequinone with toxic activity against a broad spectrum of organisms. however, little is known about the biosynthetic pathway or factors that regulate cercosporin production. analysis of a cdna subtraction library comprised of genes that are up-regulated during cercosporin synthesis revealed a sequence highly similar to mitogen-activated protein (map) kinases in other fungi. sequenc ... | 2003 | 12971599 |
| permanent genetic resources added to molecular ecology resources database 1 january 2009-30 april 2009. | this article documents the addition of 283 microsatellite marker loci to the molecular ecology resources database. loci were developed for the following species: agalinis acuta; ambrosia artemisiifolia; berula erecta; casuarius casuarius; cercospora zeae-maydis; chorthippus parallelus; conyza canadensis; cotesia sesamiae; epinephelus acanthistius; ficedula hypoleuca; grindelia hirsutula; guadua angustifolia; leucadendron rubrum; maritrema novaezealandensis; meretrix meretrix; nilaparvata lugens; ... | 2009 | 21564911 |
| diallel analysis of leaf disease resistance in inbred brazilian popcorn cultivars. | we estimated general and specific combining abilities and examined resistance to northern leaf blight (exserohilum turcicum) and to gray leaf spot (cercospora zeae-maydis) in a set of nine inbred popcorn lines. these inbreds were crossed in a complete diallel scheme without reciprocals, which produced 36 f(1) hybrids. two experiments with a square lattice design and three replications were conducted during the 2008/2009 crop season, in maringá, pr, brazil. the severity of northern leaf blight an ... | 2009 | 20013656 |
| genetic relatedness of african and united states populations of cercospora zeae-maydis. | two taxonomically identical but genetically distinct sibling species, designated groups i and ii, of cercospora zeae-maydis cause gray leaf spot of maize in the united states. isolates of the gray leaf spot pathogen from africa were compared with isolates from the united states by amplified fragment length polymorphism (aflp) analysis and restriction digests of internal transcribed spacer (its) regions and 5.8s ribosomal dna (rdna), as well as by morphological and cultural characteristics. the i ... | 2000 | 18944554 |