Developmental expression and regulation by light of two closely related ?-tubulin genes in Lupinus albus

Vassilevskaia, Tatiana; Bekman, Evguenia; Jackson, P; Ricardo, Cândido Pinto; Rodrigues-Pousada, Claudina

doi:10.1007/bf00041404

Cited by 13 publications

(9 citation statements)

References 26 publications

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“…First, the transcripts of PvGLP1 are stored in the dry seed, as was previously shown for gene transcription products that are needed during the early stages of germination, i.e. b-tubulin genes (Vassilevskaia et al 1996) and LA-ACS1, an isoform of 1-aminocyclopropane-1-carboxylate-synthase (Bekman et al 2000). Second, the transcripts of PvGLP1 in the embryo axis strongly increased a few hours before radicle emergence (Fig.…”

Section: Discussionmentioning

confidence: 94%

A gene encoding a germin-like protein, identified by a cDNA?AFLP approach, is specifically expressed during germination of Phaseolus vulgaris

Aubry¹,

Paven²,

Chateigner‐Boutin³

et al. 2003

Planta

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In order to identify markers of germination in Phaseolus vulgaris L., a cDNA-amplified fragment length polymorphism (AFLP) approach was conducted on mRNAs from embryo axes and from cotyledons. Among changes observed throughout the germination process, a cDNA fragment not detected 9 h after imbibition (HAI) but present specifically in axes 24 HAI was further studied. The complete cDNA was recovered by rapid amplification of cDNA ends, then cloned and sequenced. It includes an open reading frame predicting a 206-amino-acid polypeptide of 21.8 kDa. Analysis of the nucleotide sequence and deduced amino acid sequence revealed a high homology with germin-like proteins (GLPs), and particularly with an auxin-binding protein from peach, ABP19, that belongs to the GLP family. Thus, we propose that this cDNA encodes the first GLP described in P. vulgaris, designated PvGLP1. Northern blot analysis carried out on mRNAs from seed axes showed a dramatic increase in PvGLP1 expression a few hours before radicle emergence (17 HAI). Among mature vegetative tissues, PvGLP1 expression was very weak in pods and not detected in leaves, stems or roots. Immunoblot analysis using antibodies raised against AtGER3 from Arabidopsis thaliana showed that the protein could be detected only in axes from the dry seed stage onwards, at a steady-state level. Then, PvGLP1 expression seems to be associated with the early stages of embryo axis growth. The high homology indicated with ABP19 led us to study the effect of different concentrations of indole-3-acetic acid (IAA) on PvGLP1 expression during germination. Whereas no effect was noticed at low concentrations (1, 5, 10 microM), a marked decrease in PvGLP1 mRNA level was observed in axes of seeds imbibed with 100 microM IAA. Thus, PvGLP1 gene expression is not stimulated by auxin and, moreover, it might be inhibited by high concentrations of IAA.

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Section: Discussionmentioning

confidence: 94%

A gene encoding a germin-like protein, identified by a cDNA?AFLP approach, is specifically expressed during germination of Phaseolus vulgaris

Aubry¹,

Paven²,

Chateigner‐Boutin³

et al. 2003

Planta

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“…Alternatively, there could be a more direct connection to this phenotype if the actin cytoskeletal system itself is light regulated. For example, the expression of plant tubulin genes is light regulated (Jacobshagen and Johnson, 1994;Tonoike et al, 1994;Vassilevskaia et al, 1996), and several Arabidopsis ␣-and ␤-tubulin gene family members and one actin (ACT11) are repressed by light during seedling development (Leu et al, 1995;Huang et al, 1997). Microtubule dynamics in some cell types are entrained as part of the circadian clock (Fukuda et al, 1998).…”

Section: Loss Of Light Regulation In Prf1-1 Mutantsmentioning

confidence: 99%

Small Changes in the Regulation of One Arabidopsis Profilin Isovariant, PRF1, Alter Seedling Development

2001

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Profilin (PRF) is a low-molecular-weight actin binding protein encoded by a diverse gene family in plants. Arabidopsis PRF1 transcripts are moderately well expressed in all vegetative organs. A regulatory mutant in PRF1 , prf1-1 , was isolated from a library of T-DNA insertions. The insertion disrupted the promoter region of PRF1 100 bp upstream from the transcriptional start site. Although steady state levels of PRF1 transcripts appeared normal in mature prf1-1 plants, the levels in young seedlings were only one-half those observed in wild type. Reactions with a PRF1 isovariant-specific monoclonal antiserum and general anti-profilin antisera demonstrated that PRF1 protein levels also were one-half those found in wild-type seedlings, although total profilin levels were unaffected. Mutant seedlings no longer could downregulate PRF1 levels in the light, as did wild type. Consistent with their molecular phenotypes, young mutant seedlings displayed several morphological phenotypes but developed into apparently normal adult plants. Their initial germination rate and development were slow, and they produced excessive numbers of root hairs. Mutant seedlings had abnormally raised cotyledons, elongated hypocotyls, and elongated cells in the hypocotyl, typical of phenotypes associated with some defects in light and circadian responses. A wild-type PRF1 transgene fully complements the hypocotyl phenotypes in the prf1-1 mutant. The ability of profilin to regulate actin polymerization and participate directly in signal transduction pathways is discussed in light of the prf1-1 phenotypes. INTRODUCTIONThe actin cytoskeleton contributes to many of the dynamic processes directing plant development: cell polarity, division plane determination, cell elongation, and cell wall deposition (Meagher et al., 1999b). As seedlings emerge from the soil and respond to light, significant changes occur in plant morphology that must be directed at the cellular level by alterations in the cytoskeleton (Meagher et al., 2000). Because the actin binding protein profilin is particularly important to the dynamics of actin polymerization and sequestration, the regulation of plant profilin expression in cells and organs responding to changes in light levels should affect plant development. This article provides initial data demonstrating the connection between profilin regulation and plant morphology.Profilin binds monomeric G-actin and participates in several cytoskeletal functions (Gibbon and Staiger, 2000) with the potential to alter cellular and organismal development. Profilin accelerates assembly at the barbed ends of actin filaments and sequesters actin monomers, which decreases the pool of polymerizable actin once barbed ends are capped (Carlier et al., 1993;Pantaloni and Carlier, 1993;Perelroizen et al., 1996). Profilin activates actin for assembly by catalyzing ADP-to-ATP exchange on actin monomers. Profilin binds tightly to poly-L -proline, a motif present in some proteins involved in regulating the actin cytoskeleton (Ahern-Djamali et al....

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“…La-TubG1 revealed an amino acid identity ranging from 38.5 to 70.2% and 44.6 to 76.6% with fungal and animal c-tubulins, respectively. When compared with b-tubulin proteins of the same species, TubB1 and TubB2 (Vassilevskaia et al 1996), the La-TubG1 polypeptide shows 58% identity with both. This value is higher than that found for c-tubulin amino acid identity with the a-tubulin and b-tubulin in Aspergillus nidulans (Oakley and Oakley 1989).…”

Section: Isolation and Characterization Of The Lupinus Albus Gene Encmentioning

confidence: 96%

“…Tubulin genes are generally expressed in a developmental stage-specific and/or organ-specific manner (Leu et al 1995;Vassilevskaia et al 1996). We therefore analyzed the La-TubG1 and b-tubulins encoded mRNAs in L. albus seeds and in 7-day-old seedlings.…”

Section: Expression Of La-tubg1 Gene In Different Developmental Stagesmentioning

confidence: 99%

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Lupinus albus γ-tubulin: mRNA and protein accumulation during development and in response to darkness

Saibo

Straeten

Rodrigues-Pousada

2004

Planta

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We have isolated a genomic DNA fragment encoding a gamma-tubulin in white lupin ( Lupinus albus L.). The predicted polypeptide encoded by the La-TubG1 gene possesses between 91 and 95% identity with other higher-plant gamma-tubulins. The mRNA and protein level of lupin gamma-tubulin is highly correlated with beta-tubulin as well as with the growth rate of the tissue. Both La-TubG1 transcript and gamma-tubulin protein expression levels are down-regulated in the embryonic axis of dry seeds as compared with the embryonic axis of germinated seeds. In 7-day-old seedlings, the La-TubG1 gene is ubiquitously expressed, with the highest level found in immature leaves. In contrast, La-TubG1 gene expression is down-regulated in mature leaves. The gamma-tubulin protein level follows a similar age-dependent accumulation, decreasing during leaf development. The expression of the gamma-tubulin gene in the hypocotyl is down-regulated by light. Nevertheless, the protein levels were not significantly altered by light, suggesting that gamma-tubulin accumulation might be controlled at both transcriptional and protein levels. Immunocytochemistry studies showed that lupin gamma-tubulin displays the localization observed in most plant microtubule arrays, corroborating a functional conservation in different species.

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Developmental expression and regulation by light of two closely related ?-tubulin genes in Lupinus albus

Cited by 13 publications

References 26 publications

A gene encoding a germin-like protein, identified by a cDNA?AFLP approach, is specifically expressed during germination of Phaseolus vulgaris

A gene encoding a germin-like protein, identified by a cDNA?AFLP approach, is specifically expressed during germination of Phaseolus vulgaris

Small Changes in the Regulation of One Arabidopsis Profilin Isovariant, PRF1, Alter Seedling Development

Lupinus albus γ-tubulin: mRNA and protein accumulation during development and in response to darkness

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