RACETTE, S., and TORREY, J. G. 1989. Root nodule initiation in Gymnostoma (Casuarinaceae) and Shepherdia (Elaeagnaceae) induced by Frankia strain HFPGpIl. Can. J. Bot. 67: 2873-2879. Seedlings of Gymnostoma papuanum (Casuarinaceae) and Shepherdia argentea (Elaeagnaceae) were grown in water culture and inoculated with Frankia strain HFPGpIl. Root nodule initiation and early nodule development we...

In this review, we summarize the different biosynthesis-related pathways that contribute to the regulation of endogenous auxin in plants. We demonstrate that all known genes involved in auxin biosynthesis also have a role in root formation, from the initiation of a root meristem during embryogenesis to the generation of a functional root system with a primary root, secondary lateral root branch...

Root hairs are an extensive structure of root epidermal cells and are critical for nutrient acquisition, soil anchorage, and environmental interactions in sessile plants. The phytohormone ethylene (ET) promotes root hair growth and also mediates the effects of different signals that stimulate hair cell development. However, the molecular basis of ET-induced root hair growth remains poorly under...

Roots of many higher plants increase in diameter through the enlargement of cells formed in a vascular cambium. After the seedling plant is established, thickening begins near the root base by the initiation of cell divisions in the procambial tissue of the central cylinder. How the vascular cambium is initiated, what maintains cambial activity and causes it to extend, with time, along the root...

Branching by de novo formation of lateral roots along the primary root of Arabidopsis seedlings follows a complex longitudinal and transverse pattern. How this pattern is generated is presently under debate. The 'bending hypothesis' proposes that lateral root primordia are initiated by a local accumulation of auxin at the convex side of bends resulting from deflections through obstacles, gravit...