Possible Involvement of Phosphoinositide-Ca2+ Signaling in the Regulation of  -Amylase Expression and Germination of Rice Seed (Oryza sativa L.)

Kashem, Mohammad Abul; Itoh, Kazuyoshi; Iwabuchi, Satoru; Hori, Hidetaka; Mitsui, Toshiaki

doi:10.1093/pcp/41.4.399

Cited by 64 publications

(41 citation statements)

References 42 publications

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“…PLC signaling, which produces an Ins(1,4,5)P 3 second messenger, has been implicated in several plant stress responses (Shacklock et al, 1992;Lee et al, 1996;Perera et al, 1999Perera et al, , 2001Perera et al, , 2005Kashem et al, 2000;Reggiani and Laoreti, 2000;Shigaki and Bhattacharyya, 2000;DeWald et al, 2001;Ortega and Perez, 2001;Liu et al, 2006). Because some 5PTase enzymes can act to hydrolyze this second messenger, the 5PTase genes are logical targets for altering Ins(1,4,5)P 3 levels and stress responses in plants.…”

Section: Discussionmentioning

confidence: 99%

Inositol Polyphosphate 5-Phosphatases 1 and 2 Are Required for Regulating Seedling Growth

et al. 2007

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Signals can be perceived and amplified at the cell membrane by receptors coupled to the production of a variety of second messengers, including myoinositol 1,4,5-trisphosphate [Ins(1,4,5)P 3 ]. The myoinositol polyphosphate 5-phosphatases (5PTases; EC 3.1.3.56) comprise a large protein family that hydrolyzes 5-phosphates from a variety of myoinositol phosphate (InsP) and phosphoinositide phosphate (PtdInsP) substrates. Arabidopsis thaliana has 15 genes encoding 5PTases. Biochemical analyses of a subgroup of 5PTase enzymes suggest that these enzymes have both overlapping and unique substrate preferences. Ectopic expression of these genes in transgenic plants can reduce Ins(1,4,5)P 3 levels and alter abscisic acid (ABA) signaling. To further explore the function of 5PTases in signaling, we have identified and characterized T-DNA insertional mutants for 5PTase1 and 5PTase2 and produced a double mutant. When grown in the dark, the seeds from these mutants germinate faster than wildtype seeds and the mutant seedlings have longer hypocotyls than wild-type seedlings. Seeds from these mutant lines also demonstrate an increase in sensitivity to ABA. These changes in early seedling growth are accompanied by mass increases in Ins(1,4,5)P 3 , but not by changes in endogenous ABA content. By labeling the endogenous myoinositol pool in 5ptase1 and 5ptase2 mutants, we detected increases in Ins(1,4,5)P 3 and a decrease in PtdIns, PtdIns(4)P, and phosphatidylinositol (4,5) bisphosphate. Taken together, these data indicate that the At5PTase1 and At5PTase2 genes have nonredundant roles in hydrolyzing inositol second-messenger substrates and that regulation of Ins(1,4,5)P 3 levels is important during germination and early seedling development.

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Section: Discussionmentioning

confidence: 99%

Inositol Polyphosphate 5-Phosphatases 1 and 2 Are Required for Regulating Seedling Growth

et al. 2007

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“…Genomic DNA (5 µg) isolated from young leaves of control and transgenic rice plants was digested with EcoRI, and separated by gel electrophoresis on 1% agarose gels and blotted onto a Hybond N + membrane (Amersham). The α amylase I 1 and α amylase II 4 gene specific DNA 6,26) were used as the radioactive probe for Southern blot analysis. Northern 18,26) and Western blotting 6,10) were performed according to the procedure described previously.…”

Section: Plant Materialsmentioning

confidence: 99%

“…The α amylase I 1 and α amylase II 4 gene specific DNA 6,26) were used as the radioactive probe for Southern blot analysis. Northern 18,26) and Western blotting 6,10) were performed according to the procedure described previously. When peroxidase conjugated anti rabbit (or mouse) IgG IgG was used as the second antibody, the protein bands were visualized with ECL (enhanced chemiluminescence, Amersham), and quantified by LAS 3000 (Fuji film).…”

Section: Plant Materialsmentioning

confidence: 99%

.ALPHA.-Amylase Affects Starch Accumulation in Rice Grains

Asatsuma¹,

Sawada²,

Kitajima³

et al. 2006

J. Appl. Glycosci.

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α Amylases (EC 3.2.1.1) in cereal are polymorphic enzymes. Ten distinct α amylase genes have been cloned and sequenced, 1 3) and more than 20 native α amylase isoforms have been identified and characterized in rice. 4 6) α Amylase I 1 encoded by RAmy1A is a glycoprotein bearing typical N linked oligosaccharide chains. 7,8) This isoform is heat stable compared with the other isoforms. The conjugation of an oligosaccharide side chain to polypeptide was thought to be involved in its heat stability.9,10) In germinating rice seeds, the expression of α amylase I 1 is regulated by gibberellin at both transcriptional and post transcriptional steps. 11,12) The enzyme is synthesized in the scutellar epithelium and the aleurone layer, and subsequently secreted to the starchy endosperm.6) The experimental data obtained by employing the transgenic rice plant with suppressed expression of α amylase I 1 revealed that this isoform plays an important role during seed germination and seedling growth. 13)α Amylase II 4 encoded by RAmy3D (Amy3) is actively expressed in suspension cultured cells derived from the rice embryo. The α amylase II 4 expression is regulated by sugars transcriptionally and post transcriptionally.14 18) At an early stage of germination, α amylase II 4 is a predominant isoform expressed in the coleoptile tissues of rice seed. This isoform is also expressed and secreted from the scutellar epithelium at the early stage of germination and the aleurone layer at the later stage.6) The expression of α amylase II 3 encoded by RAmy3E (Amy8) was detected in germinating seeds and suspension cultured cells derived from the embryo in rice. 3,5,19) The transcription of the α amylase II 3 gene has been reported to be regulated by sugars and hormones through Myb transacting factors. 20) α Amylase II 5 6 encoded by RAmy3B C was also detected in the germinating seeds.5) Similar to the other α amylase isoforms, the expression of α amylase II 5 6 was suggested be regulated by gibberellin and abscisic acid in germinating seeds. 5)As described above, α amylase is a key enzyme for germination and seedling growth of rice seeds. However, we found the typical α amylase isoforms I 1 and II 4 in ripening seeds. We examined the function of α amylase in grain during the ripening period in transgenic rice plants overexpressing the enzyme isoforms. MATERIALS AND METHODS Plant materials.The rice variety (Oryza sativa L. cv. Nipponbare) used in this study was supplied from the Niigata Agricultural Research Institute (Niigata, Japan).Assays. Starch and protein contents were determined as described by Matsukura et al . 21) and Bradford, 22) respectively. α Amylase activity was determined using β limit dextrin as the substrate. β limit dextrin was prepared by hydrolyzing potato starch solution (2% w v in 50 mM acetate buffer, pH 5.3), using crystalline potato β amylase free from α amylase (24 h, 30 C). 0.3% β limit dextrin dissolved in 50 mM acetate buffer (pH 5.3) containing 1 mM CaCl2 served as the substrate. The reaction mixture contain...

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“…Esse fato evidencia que o uso de proteção do solo, por disponibilizar maior quantidade de água às plantas (Stewart, 1994) e favorecer o desenvolvimento de microrganismos benéficos a estas (Stamets & Chilton, 1983), propicia melhores condições para o início da floração, ao mesmo tempo em que o aumento da salinidade da água de irrigação, por elevar a concentração de sais no solo (Medeiros, 1992;Kashem et al, 2000), retarda essa fase do desenvolvimento do amaranto. Pela análise de variância, observou-se que a interação proteção do solo x salinidade não foi significativa.…”

Section: Resultsunclassified

“…Nos solos afetados por sais, o Na é o que causa mais problemas, podendo interferir no crescimento das plantas (Kashem et al, 2000) e na distribuição de nutrientes nas suas partes (Viana et al, 2001). Algumas espécies vegetais apresentam rendimentos favoráveis, inclusive em condições de cultivo em alta salinidade e sodicidade, muito embora outras sejam mais sensíveis.…”

Section: Introductionunclassified

Crescimento e desenvolvimento do amaranto (amaranthus spp.) sob estresse salino e cobertura morta

Costa

Melo

Ferreira

et al. 2008

Rev. Bras. Ciênc. Solo

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Possible Involvement of Phosphoinositide-Ca2+ Signaling in the Regulation of -Amylase Expression and Germination of Rice Seed (Oryza sativa L.)

Cited by 64 publications

References 42 publications

Inositol Polyphosphate 5-Phosphatases 1 and 2 Are Required for Regulating Seedling Growth

Inositol Polyphosphate 5-Phosphatases 1 and 2 Are Required for Regulating Seedling Growth

.ALPHA.-Amylase Affects Starch Accumulation in Rice Grains

Crescimento e desenvolvimento do amaranto (amaranthus spp.) sob estresse salino e cobertura morta

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