11 December 2009
Vol 326, Issue 5959

About The Cover

Cover image expansion

COVER Viewed from the inside of a fractured rice leaf, cells of the rice pathogenic bacterium Xanthomonas oryzae pv. oryzicola invade through a stoma. Xanthomonas species inject host cells with unusual DNA binding proteins called transcription activator-like (TAL) effectors to up-regulate genes important for infection. Two studies in this issue (pages 1501 and 1509; related Perspective, page 1491) decipher TAL effector target specificity and show that new specificities can be engineered. Image: Adam Bogdanove and Harry Horner/Iowa State University; false color: Yael Kats/Science