Differentiation of aecidiospore- and uredospore-derived infection structures on cowpea leaves and on artificial surfaces by <i>Uromyces vignae</i>

Stark-Urnau, Martina; Mendgen, Kurt

doi:10.1139/b93-146

Cited by 11 publications

(3 citation statements)

References 26 publications

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“…3a-f), as previously described in their respective hosts (Rodrigues et al 1975;Silva et al 1999;Stark-Urnau and Mendgen 1993). A detailed analysis of the differentiation of infection structures in the host interaction (Fig.…”

Section: Macro-and Microscopic Analysis Of Host and Nonhost Interactionsmentioning

confidence: 90%

Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2

et al. 2011

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In Arabica coffee breeding, some of the most used sources of resistance to leaf rust (Hemileia vastatrix) are natural Coffea arabica x canephora hybrids ("Híbrido de Timor"). To decipher the cellular and molecular nature of that resistance, leaves of genotype HDT832/2, were challenged with H. vastatrix race II, and monitored using light microscopy and RT-qPCR expression analysis of genes involved in plant immunity mechanisms (receptor-like kinase, WRKY transcription factor 1, phenylalanine ammonia-lyase, chalcone synthase, 13-lipoxygenase, glycosyltransferase, pathogenesis related PR1b and PR10). These were compared to the nonhost resistance responses of HDT832/2 to the infection by the cowpea rust fungus (Uromyces vignae). H. vastatrix ceased growth more frequently after stomata penetration, forming few haustoria, inducing a hypersensitive-like response, phenol accumulation and haustorium encasement with callose. U. vignae could enter stomata but failed to form haustoria, while inducing hypersensitive-like responses and phenol accumulation. In host and nonhost interactions, activation of genes involved in signalling coincided with the differentiation of appressoria, and cellular responses (hypersensitive-like responses and accumulation of phenolic compounds) were recorded from the full appressorium or penetration hypha stages onwards. Similarly, a gene related to the JA pathway was first activated at the penetration hypha stage for both interactions, while genes related to the SA pathway were only activated in the host interaction, the latter being the single clear difference between host and nonhost interactions. The cellular and molecular resistance responses of HDT832/ 2 to these rust fungi suggest that common immunity components are shared between host and nonhost resistance, which may explain the longer durability of this resistance.

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Section: Macro-and Microscopic Analysis Of Host and Nonhost Interactionsmentioning

confidence: 90%

Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2

et al. 2011

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“…Infected leaf pieces, about 2–4 cm 2 , were fixed overnight in a 2% solution of glutaraldehyde in 0.1 M sodium phosphate buffer, pH 7.2. Leaf pieces were then sectioned with a freezing microtome (Leica CM1850) and the sections (20–25 μm) were stained with DAPI (as before), for 2 h. The sections were then washed with distilled water, stained with an aqueous solution of 0.3% w/v diethanol for 2–3 s, washed again with distilled water and mounted in 50% v/v glycerol (adapted from Stark-Urnau and Mendgen, 1993 ; Skalamera and Heath, 1998 ).…”

Section: Methodsmentioning

confidence: 99%

Genome size analyses of Pucciniales reveal the largest fungal genomes

et al. 2014

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Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

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“…California Blackeye) by the pycnial-aecial phase of U. vignae (Barclay) was obtained as described (Stark-Urnau and Mendgen 1993).…”

Section: Infected Plantsmentioning

confidence: 99%

Sequential deposition of plant glycoproteins and polysaccharides at the host-parasite interface ofUromyces vignae andVigna sinensis

Stark-Urnau

Mendgen

1995

Protoplasma

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Summary. Monokaryotic haustoria (M-haustoria) of Uromyces vig-nae in Vigna sinensis cells are surrounded by an extrahaustorial matrix (ema) and the invaginated host plasmalemma, the extrahaustorial membrane (ehm). The ema was characterized with antibodies against components of the plant cell wall; the ema contained hydroxyproline-rich glycoproteins and arabinogalactans/arabinogalactan proteins, both at a higher concentration close to the ehm. Haustoria with large vacuoles had the ema encased by additional layers. An electron-translucent inner layer deposited on top of the ema contained arabinogalactans/arabinogalactan proteins, hydroxyprolinerich glycoproteins, and callose. The inner layer was surrounded by an electron-translucent middle layer with numerous dark inclusions, rich in pectin and fucose bound to xyloglucans. Finally, a more electron-dense outer layer containing arabinogalactans/arabinogalactan proteins and hydroxyproline-rich glycoproteins encased the whole structure. These polysaccharides, with the exception of callose and un-esterified pectin, 'were also found in the plant Golgi apparatus. The polysaccharides were synthesized in the trans Golgi cisternae and secreted into the host-parasite interface. The secretory events seem to be coupled to endocytosis since numerous coated pits were found on the ehm too. The pits were elongated, sometimes formed tubules and the coat reacted with an antibody against plant clathrin. Our results suggest intensive membrane recycling around haustoria, together with the secretion of cell wall material, which in the case of more or less vacuolated haustoria seems to be responsible for encasement

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Differentiation of aecidiospore- and uredospore-derived infection structures on cowpea leaves and on artificial surfaces by Uromyces vignae

Cited by 11 publications

References 26 publications

Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2

Cellular and molecular analyses of coffee resistance to Hemileia vastatrix and nonhost resistance to Uromyces vignae in the resistance-donor genotype HDT832/2

Genome size analyses of Pucciniales reveal the largest fungal genomes

Sequential deposition of plant glycoproteins and polysaccharides at the host-parasite interface ofUromyces vignae andVigna sinensis

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