Mechanical Transmission, Purification and Properties of an Isolate of Maize Stripe Virus from Venezuela

A Venezuelan isolate of maize stripe virus (MStpV) was successfully transmitted mechanically and by the leafhopper Peregrinus maidis from field infected plants to sweet cv. Iochief. After purification of maize infected with MStpV, fine spiral filamentous particles about 4 nm in diameter and with variable lengths were consistently associated with a nucleoprotein band present in CsCl or Cs₂SO₄ isopycnic gradients. Purified preparations exhibited a typical nucleoprotein absorption spectrum with a maximum at 260–263 nm and a minimum at 240–243 nm and a 260–280 ratio of 1.38. The density of the nucleoprotein in CsCl gradients was estimated at 1.29 g/ml. The sedimentation coefficient was calculated at 62 S. The nucleoprotein consisted of 5 % single stranded RNA and a capsid protein of molecular weight 33.500 daltons. Large quantities of non-capsid proteins were isolated from infected tissue with a molecular weight of 17.500 and 16.500 daltons. Peregrinus maidis, injected with purified MStpV preparation failed to transmit the disease to healthy plants. However, they were infectious when injected with clarified infected plant sap. Antisera against capsid and non-capsid proteins from MStpV-Florida strain reacted positively with the Venezuelan antigens.