ISSN:
1432-2048
Keywords:
Anoxia
;
Auxin binding
;
Coleoptile
;
Oryza (auxin binding)
;
Oxygen sensitivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract As described previously, the sensitivity of rice (Oryza sativa L.) coleoptiles to auxin is modulated by oxygen. Under anoxia, coleoptile elongation is insensitive to exogenously applied indole-3-acetic acid (IAA), whereas its sensitivity increases in air in the presence of the exogenous stimulus. Here we report the presence of two independent classes of membrane-bound IAA-binding sites in air-grown coleoptiles. Their binding activity is strictly correlated with the system's sensitivity to IAA. We designate them as site A (high affinity) and site B (low affinity). Site A shows a relatively fast response to anoxia, and is highly specific for auxins. Regulation of site-A binding activity through ATP, whose availability decreases under anoxia, is postulated. A role as auxin carrier is suggested for site B.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00393692
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