Effect of Phytolectins on Isolated Protoplasts from Plants

Abstract
The effects of three phytolectins on isolated plant protoplasts have been examined. It was found that concanavalin A, phytohemagglutinin and wheat germ agglutinin were all capable of agglutinating protoplasts isolated from a variety of plant species. The incorporation of 3H-uridine, 3H-thymidine and 14C-leucine into RNA, DNA and protein respectively was also stimulated by the three lectins in isolated protoplasts. Treatment with α-methyl-D-mannoside abolished both the agglutinating and incorporation enhancing effects of concanavalin A (Con A) on barley protoplasts. Protoplasts with a regenerated cell wall also failed to respond to lectin treatment. These results suggest that lectin-binding to the protoplast membrane surface is required before either agglutination or metabolic stimulation will result.