Cassia Yellow Blotch Virus: a New Bromovirus from an Australian Native Legume, Cassia pleurocarpa

Abstract

SUMMARY Cassia yellow blotch virus (CYBV) is a previously undescribed bromovirus infectingthe Australian indigenous legume, Cassia pleurocarpa, in western Queensland.Although CYBV infected test plants in several families, symptoms were usually restricted to local lesions on the inoculated leaves. Systemic infection occurred in only eight leguminous species and in the non-legume, Nicotiana clevelandii. Chenopodium amaranticolor was a suitable host for local lesion assays and CYBV was readily purified from N. clevelandii. Purified CYBV preparations, when negatively stained, contained isometric particles 25 to 27 nm in diameter with a penetrated central core of approx. 10 nm. The virions sedimented as a single component with a sedimentation coefficient (SE0,w) of 85S and had an isoelectric point of 3.6. At pH 7.0, the virions sedimented more slowly than at pH 5-0 and 6.5 probably because they swelled. Purified virions contained a single coat protein species with a molecular weight of 20800 comprising 196 amino acid residues as estimated by FITMOL analysis of the amino acid composition. The virion genome consisted of four single-stranded RNA molecules of which only the three largest were required for infectivity. CYBV appeared to be serologically unrelated to three other bromoviruses and this lack of relationship correlated with differences in their coat protein amino acid compositions.

A review of the biology and ecology of Florida beggarweed (Desmodium tortuosum)

“…Cassia yellow blotch bromovirus was first identified and found to infect Florida beggarweed in Australia. Hosts of this bromovirus include corn, cucumber (Cucumis sativus L.), dry bean, and soybean (Brunt et al 1999;Dale et al 1984). Nonsusceptible hosts include barley (Hordeum vulgare L.), jimsonweed, oat (Avena sativa L.), pea (Pisum sativum L.), peanut, pigeon pea [Cajanus cajun (L.) Millsp.…”

“…], sorghum [Sorghum bicolor (L.) Moench. ], and sunflower (Helianthus annuus L.) (Brunt et al 1999;Dale et al 1984). Johnson et al (1996) found that Florida beggarweed was susceptible to tomato spotted wilt tospovirus (TSWV) but was not a preferred host for thrips (Frankliniella spp.)…”

A review study on chemical composition and molecular structure of newly plant gum exudates and seed gums

“…pleurocarpa is a bush-like plant including branched green leaves and bright colored flowers, wildly grown in the northern Australia (Dale, Gibbs, & Behncken, 1984). The seed endosperm of C. pleurocarpa is also a source of non-ionic water soluble galactomannan composed of D-galactose and D-mannose in the molar ratio of 1.00:2.01 (Singh et al, 2009a).…”

Structure elucidation and properties of a non-ionic galactomannan derived from the Cassia pleurocarpa seeds

“…In this study, we report on the structure and properties of the seed gum extracted from Cassia pleurocarpa, a bush-like plant with branched green leaves and bright colored flowers, found distributed in the northern Australia [20]. In order to explore the potential applications of the galactomannan isolated from C. pleurocarpa, the structural elucidation, rheological properties, water/saline retention, gelling behavior, and shelf life of the galactomannan were extensively studied and discussed.…”