Dim-Red-Light-Induced Increase in Polar Auxin Transport in Cucumber Seedlings1

Shinkle, James R.; Kadakia, Rajan; Jones, Alan M.

doi:10.1104/pp.116.4.1505

Cited by 33 publications

(10 citation statements)

References 36 publications

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“…It was also reported that red light causes an increase in polar auxin transport in cucumber (Shinkle et al 1998) and recently two closely related ATP-binding cassette (ABC) transporter genes, AtMDR1 and AtPGP1, were shown to be functional in light and auxin responses (Lin and Wang 2005). So, in some cases red light could aVect the velocity of IAA transport.…”

Section: Discussionmentioning

confidence: 96%

Red light causes a reduction in IAA levels at the apical tip by inhibiting de novo biosynthesis from tryptophan in maize coleoptiles

Nishimura

Mori

Furukawa

et al. 2006

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When maize coleoptiles were unilaterally exposed to red light (7.9 micromol m(-2)s(-1) for 5 min), 3 h after treatment IAA levels in coleoptiles decreased in all regions, from top to basal, with levels about 60% of dark controls. Localized irradiation in the 5 mm top zone was sufficient to cause the same extent of IAA reduction in the tips to that in the tips of whole irradiated shoots. When coleoptiles were treated with N-1-naphthylphthalamic acid (NPA), an accumulation of IAA in the tip and a decrease of diffusible IAA from tips were simultaneously detected. IAA accumulation in red-light treated coleoptiles by NPA was much lower than that of dark controls. NPA treatment did not affect the content of conjugated IAA in either dark or light treated coleoptile tips. When (13)C(11) (15)N(2)-tryptophan (Trp) was applied to the top of coleoptiles, substantial amounts of stable isotope were incorporated into free IAA in dark and red-light treated coleoptile tips. The ratio of incorporation was slightly lower in red-light treated coleoptile tips than that in dark controls. The label could not be detected in conjugated IAA. The rate of basipetal transport of IAA was about 10 mm h(-1) and the velocity was not affected by red light. These results strongly suggest that red light does not affect the rates of conversion of free IAA to the conjugate form or of the basipetal transport, but just reduces the IAA level in the tips, probably inhibited by IAA biosynthesis from Trp in this region.

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Section: Discussionmentioning

confidence: 96%

Red light causes a reduction in IAA levels at the apical tip by inhibiting de novo biosynthesis from tryptophan in maize coleoptiles

Nishimura

Mori

Furukawa

et al. 2006

Planta

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“…It is also noteworthy that NPA is less eective than TIBA in inhibiting gravicurvature. Recently, dierences in sensitivity to TIBA and NPA were observed for the inhibition of polar auxin transport through cucumber hypocotyls (Shinkle et al 1998) and it was suggested that NPA and TIBA may not compete for the same binding site on the IAA-eux carrier. The IAA-eux carrier appears to consist of several protein components (Morris et al 1991;Cox and Muday 1994), and TIBA and NPA may bind to separate components and dierentially aect polar auxin transport.…”

Section: Discussionmentioning

confidence: 99%

The auxin-resistant diageotropica mutant of tomato responds to gravity via an auxin-mediated pathway

Rice

Lomax

2000

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Hypocotyls of the diageotropica (dgt) mutant of tomato (Lycopersicon esculentum Mill.) do not elongate in response to exogenous auxin, but can respond to gravity. This appears paradoxical in light of the Cholodny-Went hypothesis, which states that shoot gravicurvature results from asymmetric stimulation of elongation by auxin. While light-grown dgt seedlings can achieve correct gravitropic reorientation, the response is slow compared to wild-type seedlings. The sensitivity of dgt seedlings to inhibition of gravicurvature by immersion in auxin or auxin-transport inhibitors is similar to that of wild-type plants, indicating that both an auxin gradient and auxin transport are required for the gravitropic response and that auxin uptake, efflux, and at least one auxin receptor are functional in dgt. Furthermore, dgt gravicurvature is the result of asymmetrically increased elongation as would be expected for an auxin-mediated response. Our results suggest differences between elongation in response to exogenous auxin (absent in dgt) and elongation in response to gravistimulation (present but attenuated in dgt) and confirm the presence of two phases during the gravitropic response, both of which are dependent on functional auxin transport.

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“…This suggests that seedlings of H. courbaril respond to light in a similar way to that of Arabidopsis and cucumber. Considering the results of Shinkle et al (1998) on the influence of light on auxin polar transport, the hormonal control observed could play an important ecophysiological role in seedlings of H. courbaril by promoting synchronism between growth and reserve degradation under variable light conditions (Fig. 6).…”

Section: Synchronism and Ecological Functionmentioning

confidence: 99%

“…Recently, studies have demonstrated the importance of polar auxin transport in many aspects of plant development, such as the expansion of hypocotyl of cucumber (Shinkle et al, 1998), Arabidopsis (Jensen et al, 1998), and tomato (Kraepiel et al, 2001) hypocotyls, as well as the development of lateral roots (Reed et al, 1998) and the differentiation of leaf and cotyledon veins in Arabidopsis (Sieburth, 1999). Polar auxin transport is also considered to be a coordinator of rhythmicity in the extension rate oscillations of the first internode in Arabidopsis (Jouve et al, 1999).…”

Section: Auxin and Xyloglucan Mobilizationmentioning

confidence: 99%

“…As H. courbaril is a shade-tolerant species (Souza and Válio, 1999), this kind of correlation highlights the existence of a synchronism among the rates of storage mobilization/product utilization, depending on light intensity or light quality. Shinkle et al (1998) demonstrated that red light is capable of inducing polar transport of auxin in Arabidopsis and cucumber, respectively. However, Kraepiel et al (2001) showed indirectly that in tomato, the transport was independent of light.…”

Section: Synchronism and Ecological Functionmentioning

confidence: 99%

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The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

et al. 2004

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Hymenaea courbaril is a leguminous tree species from the neotropical rain forests. Its cotyledons are largely enriched with a storage cell wall polysaccharide (xyloglucan). Studies of cell wall storage polymers have been focused mostly on the mechanisms of their disassembly, whereas the control of their mobilization and the relationship between their metabolism and seedling development is not well understood. Here, we show that xyloglucan mobilization is strictly controlled by the development of first leaves of the seedling, with the start of its degradation occurring after the beginning of eophyll (first leaves) expansion. During the period of storage mobilization, an increase in the levels of xyloglucan hydrolases, starch, and free sugars were observed in the cotyledons. Xyloglucan mobilization was inhibited by shoot excision, darkness, and by treatment with the auxin-transport inhibitor N-1-naphthylphthalamic acid. Analyses of endogenous indole-3-acetic acid in the cotyledons revealed that its increase in concentration is followed by the rise in xyloglucan hydrolase activities, indicating that auxin is directly related to xyloglucan mobilization. Cotyledons detached during xyloglucan mobilization and treated with 2,4-dichlorophenoxyacetic acid showed a similar mobilization rate as in attached cotyledons. This hormonal control is probably essential for the ecophysiological performance of this species in their natural environment since it is the main factor responsible for promoting synchronism between shoot growth and reserve degradation. This is likely to increase the efficiency of carbon reserves utilization by the growing seedling in the understorey light conditions of the rain forest.

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Dim-Red-Light-Induced Increase in Polar Auxin Transport in Cucumber Seedlings1

Cited by 33 publications

References 36 publications

Red light causes a reduction in IAA levels at the apical tip by inhibiting de novo biosynthesis from tryptophan in maize coleoptiles

Red light causes a reduction in IAA levels at the apical tip by inhibiting de novo biosynthesis from tryptophan in maize coleoptiles

The auxin-resistant diageotropica mutant of tomato responds to gravity via an auxin-mediated pathway

The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

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