29 June 1990
Vol 248, Issue 4963

About The Cover

A view of the localized phytoalexin response of a single epidermal cell of Sorghum bicolor to the phytopathogen Colletotrichum graminicola. The response is characterized by the accumulation of phytoalexins in cytoplasmic inclusions that enlarge as they move toward the fungal infection structure, releasing their contents and restricting the growth of the pathogen. See page 1637. [Photograph by Ralph L. Nicholson]