Biomaterial Database

Auxin promotes gibberellin biosynthesis in decapitated tobacco plants. 2001

C M Wolbang, and J J Ross

School of Plant Science, University of Tasmania, GPO Box 252-55, Hobart, Tasmania 7001, Australia.

Excision of the apical bud (decapitation) of tobacco (Nicotiana tabacum L.) plants reduced the endogenous levels of indole-3-acetic acid (IAA), gibberellin A20 (GA20), and GA1 (the bioactive GA), in internode tissue below the excision site. Application of IAA to the stump of decapitated plants dramatically increased GA20 content, to a level 3-fold greater than in intact plants. Gibberellin A1 content was also increased by IAA. Decapitation reduced the conversion of [14C]GA19 to [14C]GA20 and of [14C]GA20 to [14C]GA1, and appeared to promote the deactivation pathway [14C]GA20 to [14C]GA29 to [14C]GA29-catabolite. Application of auxin counteracted these effects, but did not restore the conversion of [14C]GA20 to [14C]GA1 to the level found in intact plants. The results indicate that auxin is necessary for normal GA biosynthesis in stems of tobacco.

UI	MeSH Term	Description	Entries
D007210	Indoleacetic Acids	Acetic acid derivatives of the heterocyclic compound indole. (Merck Index, 11th ed)	Auxin,Auxins,Indolylacetic Acids,Acids, Indoleacetic,Acids, Indolylacetic
D010940	Plant Proteins	Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which PLANT PROTEINS, DIETARY is available.	Plant Protein,Protein, Plant,Proteins, Plant
D002250	Carbon Radioisotopes	Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.	Radioisotopes, Carbon
D005875	Gibberellins	A class of plant growth hormone isolated from cultures of GIBBERELLA FUJIKUROI, a fungus causing Bakanae disease in rice. There are many different members of the family as well as mixtures of multiple members; all are diterpenoid acids based on the gibberellane skeleton.	Gibberellin
D014026	Nicotiana	A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; the dried leaves of Nicotiana tabacum are used for SMOKING.	Tobacco Plant,Nicotiana tabacum,Plant, Tobacco,Plants, Tobacco,Tobacco Plants
D018547	Plant Stems	Parts of plants that usually grow vertically upwards towards the light and support the leaves, buds, and reproductive structures. (From Concise Dictionary of Biology, 1990)	Plant Stem,Stem, Plant,Stems, Plant