Self-cleaving circular RNA associated with rice yellow mottle virus is the smallest viroid-like RNA.

We report the sequence, structural features, and self-cleaving activity of the small circular RNA (sc-RNA) associated with rice yellow mottle sobemovirus (RYMV). At 220 nucleotides, the RYMV sc-RNA represents the smallest naturally occurring viroid-like RNA currently documented in the literature. It is similar to other circular satellite RNAs (sat-RNAs) and viroids in being G-C-rich with a high level of self-complementarity.

Replication and encapsidation of the viroid-like satellite RNA of lucerne transient streak virus are supported in divergent hosts by cocksfoot mottle virus and turnip rosette virus.

Cocksfoot mottle sobemovirus supports replication and encapsidation of the viroid-like satellite RNA (sat-RNA) of lucerne transient streak virus (LTSV) in two monocotyledonous species, Triticum aestivum and Dactylis glomerata. Additionally, LTSV sat-RNA replicates effectively in the presence of turnip rosette sobemovirus in Brassica rapa, Raphanus raphanistrum and Sinapsis arvensis, but not in Thlaspi arvense or Nicotiana bigelovii, indicating that host species markedly influence this interaction. Previous reports of the association between LTSV sat-RNA and helper sobemoviruses were limited to dicotyledonous hosts.

Pathogenesis-related proteins in lima bean leaves infected with tobacco ringspot virus and their distribution within and around local lesions.

Tobacco ringspot virus (TRSV) induces circular, darkbrown local lesions on primary leaves of lima bean (Phaseolus lunatus cv Nemagreen) with a concomitant production of three basic and three acidic pathogenesisrelated (PR) proteins. The three basic proteins are: a 21 kDa protein related serologically to Pinto bean PR-4d and tobacco PR-5 proteins; a 36 kDa glucanase that is related to tobacco PR-2; and, a 31 kDa chitinase related serologically to ethylene-induced bean chitinase. The three acidic 18 kDa lima bean PR proteins are serologically similar and probably are charged isomers of the same protein.

Temperature-induced structural stabilization of the encapsidated RNA of southern bean mosaic virus and its biologic significance.

Virions of southern bean mosaic virus (SBMV) show two distinct sensitivity patterns upon heating. Infectivity loss and capsid denaturation occur concurrently if virions are exposed at 50-55 degrees in 0.1 M sodium phosphate buffer, pH 7.

pH-Dependent urea sensitivity of southern bean mosaic virus.

The behavior of southern bean mosaic virus (SBMV) virions in urea was markedly pH dependent and revealed several novel features. In the absence of urea (5 degrees , 1 hr) SBMV was stable as a 115 S entity between pH 2.5 and 9.