Linked Life Data

16662991

Source:http://linkedlifedata.com/resource/pubmed/id/16662991

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-6-29
pubmed:abstractText
The role of auxin and protons in the gravitropic response of the sunflower (Helianthus annuus L. cv Sungold) hypocotyl has been investigated. No physiological asymmetry in acid-growth capacity could be detected between the upper and lower surfaces of gravistimulated hypocotyls. These data imply that neutral buffers inhibit shoot gravitropism by preventing the establishment of a lateral proton gradient along gravitropically stimulated hypocotyls. Indirect evidence that auxin is involved in the establishment and/or maintenance of such a gradient derives from the quantitative assessment of the effects of exogenous auxin, anti-auxins, and vanadate on gravicurvature. At low concentrations, exogenous auxin accelerated curvature; at high concentrations, curvature was prevented. Vanadate, an inhibitor of auxin-enhanced H(+) secretion, alpha-(p-chlorophenoxy)isobutyric acid (PCIB), an anti-auxin, and 2,3,5-triiodobenzoic acid (TIBA), an auxin-transport inhibitor, prevented observable asymmetric proton excretion using a brom cresol purple agar technique and also inhibited gravicurvature. Vanadate, PCIB, and TIBA inhibition of gravicurvature could be reversed with acid treatment to the lower surface of a gravistimulated hypocotyl. Auxin treatment to the lower surface of a gravistimulated hypocotyl did not reverse vanadate-induced inhibition, but it did partially reverse PCIB- and TIBA-induced inhibition. These results indicate a close relationship between the acid-growth theory and the differential growth responses of the sunflower hypocotyl during gravitropism.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
May
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
99-104
pubmed:dateRevised
2010-9-15
pubmed:year
1983
pubmed:articleTitle
Evidence for a Relationship between H Excretion and Auxin in Shoot Gravitropism.
pubmed:affiliation
Department of Botany, San Diego State University, San Diego, California 92182.
pubmed:publicationType
Journal Article