Presumed role of mucilage of plantain seeds in spread of tobacco mosaic virus

A strain of tobaoco mosaic virus(TMVbs) isolated fromPlantago major L. is not seed-borne with this plant species; however, plantain seeds and the mucilage on their surface also contain the virus. The mucilage shows a very low infectivity; the visoous mucilage inhibits infeotion in rubbed leaves both in a mixture with the virus and if applied before (but not after) the inoculation of the virus. Polysaccharides and hexuronic acids were detected in the great plantain seed mucilage. A mixture of mucilage and viras stored at room temperature showed s low infectivity until 33 days, but the infectivity increased oonspicuously on the 40th day, apparently simultaneously with the decay of mucilage. Polysaccharides are suggested as being responsible for the inhibition. They affect the inoculated leaf but not the virus, as ascertained by eleotron mioroscopy and serology. The seed mucilage being an important factor in the spread of plantain seeds may act as a vehicle of the virus as well.