Differential Phytotoxicity of Metabolic By-Products of Helminthosporium victoriae

Viruses of Helminthosporium (Cochlioblus) victoriae

“…As a virology graduate student (1961)(1962)(1963)(1964)(1965) at the Plant Pathology Department, Louisiana State University (LSU), the senior author was intrigued by the etiology of the transmissible disease of H. victoriae and by the pathotoxin "victorin," a cyclized pentapeptide of 814 Da (Wolpert et al, 1985) which is produced by virulent isolates of H. victoriae. The findings that victorin reproduces the disease symptoms in the absence of the fungus and that cell-free, fungal culture filtrate diluted one millionfold was not only toxic but also exhibited the same specificity toward oat genotypes as the fungus (Meehan & Murphy, 1947) were of considerable interest. During his tenure at LSU, Professors G. D. Lindberg and H. E. Wheeler were directing nationally recognized research programs on the transmissible disease of H. victoriae and mode of action of victorin, respectively.…”

Rhizoctonia solani: taxonomy, population biology and management of rhizoctonia seedling disease of soybean

“…Wyllie (1962) obtained similar findings and observed that root exudates from soybean plants stimulated mycelial growth of the invading fungal isolate. The ability to produce a number of non-host-specific toxins has been implicated as a possible factor behind the wide host range typical of most necrotrophs, although host-specific toxins have been observed with certain necrotrophs such as Cochlioblous victoriae (Meehan & Murphy, 1947), Helminthosporium maydis (Kono & Daly, 1979), Phyllosticta maydis (Danko et al, 1984) and Alternaria alternata f. sp. lycopersici (Gilchrist & Grogan, 1976).…”

Exploring fungal RiPPs from the perspective of chemical ecology

“…The toxin achieves this by binding two mitochondrial glycine decarboxylase complex proteins, cleaving the large Rubisco subunit, and as a result inhibiting the plant’s photorespiratory cycle [ 91 ]. As such, this toxin is instrumental in the establishment and survival of the fungus—provided the host oat plant is of the ‘Victoria-type’ [ 93 ] and contains the Vb gene which determines sensitivity to the toxin and by extension the pathogen [ 94 ]. Indeed the importance of victorin extends beyond its role in plant pathogenicity due to its significance in developing the concept of host-selective plant toxins [ 91 ].…”