The Interaction of Some Auxin Antagonists and 2,4‐D in Root Growth

ÅBerg, Börje

doi:10.1111/j.1399-3054.1951.tb07698.x

Cited by 28 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although indole-3-acetic acid (IAA) is the major naturally occurring auxin, numerous compounds structurally similar to IAA have been tested in both cell elongation (Jo¨nsson 1955;Å berg 1956) and auxin transport bioassays (Hertel et al 1969;Delbarre et al 1996;Parry et al 2001). From these studies indirect conclusions have been ventured concerning the ligand specificity of the corresponding receptor and transporter proteins (Å berg 1951;Katekar and Geissler 1983).…”

Section: Introductionmentioning

confidence: 99%

Species differences in ligand specificity of auxin-controlled elongation and auxin transport: comparing Zea and Vigna

Zhao¹,

Hertel

Ishikawa³

et al. 2002

Planta

View full text Add to dashboard Cite

The plant hormone auxin affects cell elongation in both roots and shoots. In roots, the predominant action of auxin is to inhibit cell elongation while in shoots auxin, at normal physiological levels, stimulates elongation. The question of whether the primary receptor for auxin is the same in roots and shoots has not been resolved. In addition to its action on cell elongation in roots and shoots, auxin is transported in a polar fashion in both organs. Although auxin transport is well characterized in both roots and shoots, there is relatively little information on the connection, if any, between auxin transport and its action on elongation. In particular, it is not clear whether the protein mediating polar auxin movement is separate from the protein mediating auxin action on cell elongation or whether these two processes might be mediated by one and the same receptor. We examined the identity of the auxin growth receptor in roots and shoots by comparing the response of roots and shoots of the grass Zea mays L. and the legume Vigna mungo L. to indole-3-acetic acid, 2-naphthoxyacetic acid, 4,6-dichloroindoleacetic acid, and 4,7-dichloroindoleacetic acid. We also studied whether or not a single protein might mediate both auxin transport and auxin action by comparing the polar transport of indole-3-acetic acid and 2-naphthoxyacetic acid through segments from Vigna hypocotyls and maize coleoptiles. For all of the assays performed (root elongation, shoot elongation, and polar transport) the action and transport of the auxin derivatives was much greater in the dicots than in the grass species. The preservation of ligand specificity between roots and shoots and the parallels in ligand specificity between auxin transport and auxin action on growth are consistent with the hypothesis that the auxin receptor is the same in roots and shoots and that this protein may mediate auxin efflux as well as auxin action in both organ types.

show abstract

Section: Introductionmentioning

confidence: 99%

Species differences in ligand specificity of auxin-controlled elongation and auxin transport: comparing Zea and Vigna

Zhao¹,

Hertel

Ishikawa³

et al. 2002

Planta

View full text Add to dashboard Cite

show abstract

“…To this end, we screened seedlings on p ‐chlorophenoxyisobutyric acid (PCIB), a chemical thought to inhibit early auxin signaling events. Although PCIB is structurally similar to some synthetic auxins (Jönsson, 1961), many years ago it was shown to inhibit several auxin‐induced physiological responses competitively (Åberg, 1950, 1951; Burström, 1950). Consistent with these results, Oono et al.…”

Section: Introductionmentioning

confidence: 99%

A small acidic protein 1 (SMAP1) mediates responses of the Arabidopsis root to the synthetic auxin 2,4‐dichlorophenoxyacetic acid

et al. 2006

View full text Add to dashboard Cite

Summary 2,4-dichlorophenoxyacetic acid (2,4-D), a chemical analogue of indole-3-acetic acid (IAA), is widely used as a growth regulator and exogenous source of auxin. Because 2,4-D evokes physiological and molecular responses similar to those evoked by IAA, it is believed that they share a common response pathway. Here, we show that a mutant, antiauxin resistant1 (aar1), identified in a screen for resistance to the anti-auxin p-chlorophenoxyisobutyric acid (PCIB), is resistant to 2,4-D, yet nevertheless responds like the wild-type to IAA and 1-napthaleneacetic acid in root elongation and lateral root induction assays. That the aar1 mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the DR5:GUS and HS:AXR3NT-GUS backgrounds, as well as by real-time PCR quantification of IAA11 expression. The two characterized aar1 alleles both harbor multi-gene deletions; however, 2,4-D responsiveness was restored by transformation with one of the genes missing in both alleles, and the 2,4-D-resistant phenotype was reproduced by decreasing the expression of the same gene in the wild-type using an RNAi construct. The gene encodes a small, acidic protein (SMAP1) with unknown function and present in plants, animals and invertebrates but not in fungi or prokaryotes. Taken together, these results suggest that SMAP1 is a regulatory component that mediates responses to 2,4-D, and that responses to 2,4-D and IAA are partially distinct.

show abstract

“…In previous papers (5,11,12) the hypothesis has been advanced that the auxin molecule is bifunctional 1 Received January 12, 1955. 2 Report of work supported in part by the Herman Frasch Foundation and in part by the National Science Foundation.…”

mentioning

confidence: 99%