Basidiospores of rust fungi (Uromyces species) differentiate infection structuresin vitro

Abstract

Mycology 12, 275-283. The effect of six different substrates on basidiospore germination and differentiation of infection structures was investigated in three species of Uromyces:U. appendiculatus var. appendiculatus, U. viciae-fabae, and U. vignae. Light and fluorescent microscopic observations were made after 3 days of incubation on the following substrates: 2 or 5% water agar, glass slide, collodion membrane, nitrocellulose sheet, and isolated host cuticle. Infection structure development up to the formation of a primary hypha was observed on hard substrates, such as 5% water agar, nitrocellulose sheet, and on isolated host cuticle. Addition of oil to the collodion membrane did not significantly increase the differentiation rate. The morphology and nuclear condition of these basidiospore infection structures were similar to those observed in host tissue. For the three directly penetrating species we studied, it appears that basidiospores respond to an unspecific stimulus, such as the thickness of host cuticle or the hardness of an artificial substrate. o 1988 Academic Press, Inc.

Infection structures of fungal plant pathogens – a cytological and physiological evaluation

“…Many fungi define the diameter and length of the penetration hypha without being influenced by the host. Basidiospores of rust fungi produce such structures of a similar size on agar (Freytag et al, 1988;Gold & Mendgen, 1991) or, in the case of uredospores, on a wide range of artificial membranes and even after thermoinduction of infection structures (Dickinson, 1949;Mendgen, 1982;Hoch & Staples, 1987).…”

“…We think that the vesicle, with its elongation, form one unit and may be regarded as a functional infection hypha. In addition to morphological studies in planta, a physiological characterization of these specialized hyphae is possible because some fungi such as rusts, M. grisea, Colletotrichum species, and to a certain extent also the grapevine powdery mildew, Uncinula necator (Dickinson, 1949;Staples et al, 1985 ;Freytag et al, 1988;Blaich, Heintz & Wind, 1989;Howard et al, 1991 a;O'Connell & Bailey, 1991) can be induced to produce their infection hyphae under artificial conditions. Some rust fungi also differentiate haustorial mother cells in the absence of host cells (Heath & Perumalla, 1988;Deising et al, 1991;Freytag & Mendgen, 1991a).…”

Carbohydrates on the surface of urediniospore‐ and basidiospore‐derived infection structures of heteroecious and autoecious rust fungi

“…Basidiospores were obtained from teliospores as described earlier (Gold & Mendgen, 1983;Freytag et al, 1988). Teliospores of U. viciae-fabae germinated soon after collection and released basidiospores w itbin 3 d of rehydration on 2 ''o (w/w) water agar.…”

“…1988; Freytag et al, 1988). Formation of urediniospore infection structures occurs on different artificial membranes, which topographically mimic a signal from the plant stoma (Wynn, 1975;Staples & Hoch, 1987).…”

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

“…Since V. vignae can reliably be cultivated under green appressorium differentiation correspond closely to dimensions house conditions and since teliospores of V. vignae do not of the lips of stomatal guard cells (Terhune et al 1991). After require a resting period (Freytag et al 1988), we perfonned appressorium formation a penetration hypha produces a sub this study with aecidiospores and uredospores of the cowpea stomatal vesicle in the substomatal chamber of the leaf that rust fungus. then elongates to form a young infection hypha (Mendgen and Our work shows that infection structures formed by aecidio Deising 1993).…”