Involvement of indole-3-acetic acid in the circadian growth of the first internode of Arabidopsis

Jouve, Laurent; Gaspar, Thomas; Kevers, Claire; Greppin, Hubert; Agosti, Robert Degli

doi:10.1007/s004250050615

Cited by 74 publications

(64 citation statements)

References 40 publications

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“…In line with the observed activity changes of GA-biosynthetic genes, the accumulation of bioactive GAs was also found to follow diurnal rhythmicity (Foster and Morgan, 1995). In addition to the daily oscillation of GA levels, the accumulation of elongationcontrolling indole-3-acetic acid and ethylene were shown to be determined by the circadian clock (Jouve et al, 1999;Thain et al, 2004). These results imply that diurnal adjustments of phytohormone synthesis are required for normal development, and circadian regulation can ensure proper hormone levels in anticipation of the regular daily changes of environmental conditions.…”

Section: Discussionsupporting

confidence: 61%

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

et al. 2006

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Plant steroid hormones, brassinosteroids (BRs), are essential for normal photomorphogenesis. However, the mechanism by which light controls physiological functions via BRs is not well understood. Using transgenic plants carrying promoter-luciferase reporter gene fusions, we show that in Arabidopsis (Arabidopsis thaliana) the BR-biosynthetic CPD and CYP85A2 genes are under diurnal regulation. The complex diurnal expression profile of CPD is determined by dual, light-dependent, and circadian control. The severely decreased expression level of CPD in phytochrome-deficient background and the red light-specific induction in wildtype plants suggest that light regulation of CPD is primarily mediated by phytochrome signaling. The diurnal rhythmicity of CPD expression is maintained in brassinosteroid insensitive 1 transgenic seedlings, indicating that its transcriptional control is independent of hormonal feedback regulation. Diurnal changes in the expression of CPD and CYP85A2 are accompanied by changes of the endogenous BR content during the day, leading to brassinolide accumulation at the middle of the light phase. We also show that CPD expression is repressed in extended darkness in a BR feedback-dependent manner. In the dark the level of the bioactive hormone did not increase; therefore, our data strongly suggest that light also influences the sensitivity of plants to BRs.

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Section: Discussionsupporting

confidence: 61%

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

et al. 2006

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“…This is quite similar to the growth pattern of the Arabidopsis inflorescence stem in which the circadian clock modulates auxin transport, auxin sensitivity, or both, to yield a rhythm in the rate of elongation (Jouve et al, 1998(Jouve et al, , 1999. The Lhc (also called CAB) mRNA levels exhibit a robust circadian pattern under free-running conditions in LL, despite the continuous presence of phytochrome in the active form (Millar and Kay, 1996).…”

Section: Possible Fine Tuning Of Xsp30 Expression By Gasupporting

confidence: 53%

“…However, there is a possibility that signals other than gibberellin also participate in the diurnal expression pattern of XSP30 in roots. One signaling molecule candidate is IAA, which controls the rate of internodal elongation, and the endogenous levels of which fluctuate in a circadian rhythm in Arabidopsis (Jouve et al, 1999). Although no circadian rhythm in IAA levels has been demonstrated in cucumber, we postulate that such a rhythm might occur.…”

Section: Possible Fine Tuning Of Xsp30 Expression By Gamentioning

confidence: 73%

“…The expression of the gene that encodes gibberellic acid (GA) 20-oxidase, a key regulatory enzyme in the gibberellin biosynthetic pathway in leaves, is controlled by the diurnal light cycle and is correlated to tuber formation in potato (Solanum tuberosum; Carrera et al, 1999). Endogenous levels of indole-3-acetic acid (IAA) fluctuate in a circadian rhythm and are involved in the growth of the internode (Jouve et al, 1999). However, the effects of circadian rhythms on the root have not been fully studied; these effects are less intuitive because roots are spatially separated from leaves, where the circadian rhythms are adjusted.…”

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confidence: 99%

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Possible Involvement of Leaf Gibberellins in the Clock-Controlled Expression of XSP30, a Gene Encoding a Xylem Sap Lectin, in Cucumber Roots

et al. 2003

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Root-produced organic compounds in xylem sap, such as hormones and amino acids, are known to be important in plant development. Recently, biochemical approaches have revealed the identities of several xylem sap proteins, but the biological functions and the regulation of the production of these proteins are not fully understood. XYLEM SAP PROTEIN 30 kD (XSP30), which is specifically expressed in the roots of cucumber (Cucumis sativus), encodes a lectin and is hypothesized as affecting the development of above-ground organs. In this report, we demonstrate that XSP30 gene expression and the level of XSP30 protein fluctuate in a diurnal rhythm in cucumber roots. The rhythmic gene expression continues for at least two or three cycles, even under continuous light or dark conditions, demonstrating that the expression of this gene is controlled by a circadian clock. Removal of mature leaves or treatment of shoots with uniconazole-P, an inhibitor of gibberellic acid (GA) biosynthesis, dampens the amplitude of the rhythmic expression; the application of GA negates these effects. These results suggest that light signals perceived by above-ground organs, as well as GA that is produced, possibly, in mature leaves, are important for the rhythmic expression of XSP30 in roots. This is the first demonstration of the regulation of the expression of a clock-controlled gene by GA.The higher plant body consists of functionally specialized organs such as the leaf, stem, flower, and root. Because plants grow in changing environments, it is essential for different organs to interact to ensure that the plant body develops and functions properly. Information transfer between organs is essential for synchronized plant development (Bernier, 1988;Kolek and Kozinka, 1991). A major route for the transfer of materials between organs consists of the vascular bundles, which are composed mainly of the xylem and phloem. Numerous materials are translocated over long distances through these bundles. The xylem is composed mainly of xylem vessels, which form a type of apoplastic space. Organic nutrients, such as amino acids, sugars, and organic acids, as well as water and inorganic nutrients, are transported through the xylem to the aboveground organs (Schurr and Schulze, 1995;Zornoza et al., 1996;Satoh et al., 1998). Interestingly, the roots control aspects of the development of aerial organs, possibly acting via growth-related compounds in the xylem sap (Kinet et al., 1993;Satoh, 1996). For example, cytokinin, abscisic acid, and other growth-related compounds that are synthesized in root tissues are involved in stomatal responses (Else et al., 1995;Liang et al., 1997), leaf senescence (Nooden et al., 1990;Soejima et al., 1992), lateral bud development (Bangerth, 1994; Beveridge et al., 1997), flower bud formation (Kinet et al., 1993), leaf greening , and adventitious root formation (Kuroha et al., 2002).Recently, macromolecules have been found in xylem sap, including oligo-and polysaccharides (Satoh et al., 1992; Campbell et al., 1995) and protei...

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“…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). However, in most cases, the action of auxin has been described in the context of influencing the metabolism of the primary cell wall in growing herbaceous seedlings.…”

Section: Auxin and Xyloglucan Mobilizationmentioning

confidence: 99%

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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Involvement of indole-3-acetic acid in the circadian growth of the first internode of Arabidopsis

Cited by 74 publications

References 40 publications

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

Diurnal Regulation of the Brassinosteroid-Biosynthetic CPD Gene in Arabidopsis

Possible Involvement of Leaf Gibberellins in the Clock-Controlled Expression of XSP30, a Gene Encoding a Xylem Sap Lectin, in Cucumber Roots

The Control of Storage Xyloglucan Mobilization in Cotyledons of Hymenaea courbaril

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