IAA transport in corn roots includes the root cap
- Univ. of SW Louisiana, Lafayette (USA)
In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing {sup 3}H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 {mu}1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 {mu}1 of sorbitol or the Ca{sup 2+} chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap.
- OSTI ID:
- 6610942
- Journal Information:
- Plant Physiology, Supplement; (USA), Vol. 89:4; ISSN 0079-2241
- Country of Publication:
- United States
- Language:
- English
Similar Records
Rapid changes in protein phosphorylation associated with gravity perception in corn roots. [Zea mays]
Increased IAA transport in axillary buds upon release from apical dominance