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Registro Completo |
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Biblioteca(s): |
Embrapa Trigo. |
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Data corrente: |
10/01/2010 |
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Data da última atualização: |
29/01/2015 |
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Autoria: |
MENGEL, K.; JUDEL, G. K. |
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Afiliação: |
Justus-Liebig Univ., Inst. of Plant Nutrition. Giessen, Germany. |
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Título: |
Effect of light intensity on the activity of starch synthesizing enzymes and starch synthesis in developing wheat grains. |
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Ano de publicação: |
1981 |
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Fonte/Imprenta: |
Physiologia Plantarum, Copenhagen, v. 51, n. 1, p. 13-18, 1981. |
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Idioma: |
Inglês |
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Conteúdo: |
The activities of starch synthesizing enzymes were investigated in wheat grains (Triticum aestivum L. cv. Kolibri) throughout the grain development period. Starch phosphorylase (E.C. 2.4.1.1) activity was especially high during the early period of grain development, while starch synthase I (ADP glucose alpha-glucan 4-alpha-glucosyl-transferase, E.C. 2.4.1.21) had a maximum activity during the later stage of grain filling. The synthetic potential of starchphosphorylase measured in vitro was about 16 times higher than the quantity of starch actually produced. It is therefore suggested that starch phosphorylase is of substantial importance in grain starch synthesis, particularly in the early period of grain growth. The synthetic potential of starch synthase I measured in vitro made up 25 to 50 per cent of the starch production and the synthetic potential of starch synthase II (UDP glucose alpha-glucan 4alpha-glucosyl-transferase, E.C. 2.4.1.11) only about 5 per cent. Reducing light intensity (shading) during the grain filling period depressed grain growth and starch production by about 20 per cent. Starch phosphorylase was not significantly affected by the reduced light intensity if enzyme activity is calculated on unit grain weight and not as activity per grain. Starch synthase I activity, however, was depressed by shading during the later stage of grain development. The depressed starch production found under low light conditions, however, cannot only be explained by an affected starch synthase I activity, but probably was also related to other still unknown factors limiting grain growth under low light conditions. The poor starch production in the shaded plants was not due to an insufficient supply of assimilates. MenosThe activities of starch synthesizing enzymes were investigated in wheat grains (Triticum aestivum L. cv. Kolibri) throughout the grain development period. Starch phosphorylase (E.C. 2.4.1.1) activity was especially high during the early period of grain development, while starch synthase I (ADP glucose alpha-glucan 4-alpha-glucosyl-transferase, E.C. 2.4.1.21) had a maximum activity during the later stage of grain filling. The synthetic potential of starchphosphorylase measured in vitro was about 16 times higher than the quantity of starch actually produced. It is therefore suggested that starch phosphorylase is of substantial importance in grain starch synthesis, particularly in the early period of grain growth. The synthetic potential of starch synthase I measured in vitro made up 25 to 50 per cent of the starch production and the synthetic potential of starch synthase II (UDP glucose alpha-glucan 4alpha-glucosyl-transferase, E.C. 2.4.1.11) only about 5 per cent. Reducing light intensity (shading) during the grain filling period depressed grain growth and starch production by about 20 per cent. Starch phosphorylase was not significantly affected by the reduced light intensity if enzyme activity is calculated on unit grain weight and not as activity per grain. Starch synthase I activity, however, was depressed by shading during the later stage of grain development. The depressed starch production found under low light conditions, however, cannot only be explained by an affec... Mostrar Tudo |
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Palavras-Chave: |
Fotosíntese. |
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Thesagro: |
Amido; Trigo. |
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Categoria do assunto: |
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Marc: |
LEADER 02250naa a2200169 a 4500
001 1834623
005 2015-01-29
008 1981 bl --- 0-- u #d
100 1 $aMENGEL, K.
245 $aEffect of light intensity on the activity of starch synthesizing enzymes and starch synthesis in developing wheat grains.
260 $c1981
520 $aThe activities of starch synthesizing enzymes were investigated in wheat grains (Triticum aestivum L. cv. Kolibri) throughout the grain development period. Starch phosphorylase (E.C. 2.4.1.1) activity was especially high during the early period of grain development, while starch synthase I (ADP glucose alpha-glucan 4-alpha-glucosyl-transferase, E.C. 2.4.1.21) had a maximum activity during the later stage of grain filling. The synthetic potential of starchphosphorylase measured in vitro was about 16 times higher than the quantity of starch actually produced. It is therefore suggested that starch phosphorylase is of substantial importance in grain starch synthesis, particularly in the early period of grain growth. The synthetic potential of starch synthase I measured in vitro made up 25 to 50 per cent of the starch production and the synthetic potential of starch synthase II (UDP glucose alpha-glucan 4alpha-glucosyl-transferase, E.C. 2.4.1.11) only about 5 per cent. Reducing light intensity (shading) during the grain filling period depressed grain growth and starch production by about 20 per cent. Starch phosphorylase was not significantly affected by the reduced light intensity if enzyme activity is calculated on unit grain weight and not as activity per grain. Starch synthase I activity, however, was depressed by shading during the later stage of grain development. The depressed starch production found under low light conditions, however, cannot only be explained by an affected starch synthase I activity, but probably was also related to other still unknown factors limiting grain growth under low light conditions. The poor starch production in the shaded plants was not due to an insufficient supply of assimilates.
650 $aAmido
650 $aTrigo
653 $aFotosíntese
700 1 $aJUDEL, G. K.
773 $tPhysiologia Plantarum, Copenhagen$gv. 51, n. 1, p. 13-18, 1981.
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Embrapa Trigo (CNPT) |
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| Registros recuperados : 2 | |
| 1. |  | VESCHI, J. L. A.; MENGEL, K. A.; NADER FILHO, A.; BALBOS, D. F.; SOUZA, V. de; CAMPOS, V.; ZAFALON, L. F. Caracterização fisico-química do leite cabras f1 (Saanen x Boer) durante a lactação In: CONGRESSO BRASILEIRO DE QUALIDADE DO LEITE: SEGURANÇA ALIMENTAR E SAÚDE PÚBLICA, 3., 2008, Recife - anais. Recife:CBQL: UFRPE, 2008. 1 CD-ROM.| Tipo: Artigo em Anais de Congresso / Nota Técnica |
| Biblioteca(s): Embrapa Pecuária Sudeste; Embrapa Semiárido. |
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| 2. | | VESCHI, J. L. A.; BALBOS, D. F.; NADER FILHO, A.; MENGEL, K. A.; SOUZA, V. de; CAMPOS, V.; ZAFALON, F. L. Caracterização celular, quantitativa e teor de cloretos do leite cabras f1 (Saanen x Boer) durante a lactação. In: CONGRESSO BRASILEIRO DE QUALIDADE DO LEITE: SEGURANÇA ALIMENTAR E SAÚDE PÚBLICA, 3., 2008, Recife - anais. Recife:CBQL: UFRPE, 2008. 1 CD - ROM.| Tipo: Artigo em Anais de Congresso / Nota Técnica |
| Biblioteca(s): Embrapa Pecuária Sudeste; Embrapa Semiárido. |
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| Registros recuperados : 2 | |
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