14 January 1994
Vol 263, Issue 5144

About The Cover

Root-knot nematodes infect a wide range of plants and establish permanent feeding sites (giant cells) in the root by inducing expression of many plant genes. The promoter sequences required by the nematode to direct expression of one such gene have been uncoupled from those necessary for expression in uninfected roots. This nematode-responsive region provides gene expression in giant cells, revealed here by the activity of a reporter gene product (blue). See page 221. [Photo: Mark A. Conkling]