Antibiotics: discontinue low-dose use.

COVER Confocal light microscopy image of a lateral root emerging from the main root (width: ~130 to 150 micrometers) of a young Arabidopsis thaliana plant (green, nuclei; red, cell walls). Lateral roots initiate deep within the primary (“mother”) root. Their emergence from the mother root is a highly regulated process requiring adjacent cells to shrink and make way for the developing lateral root. See page 178.