PROTON-PUMPING AND NITROGEN METABOLISM IN RICE UNDER HUMID TROPIC CONDITIONS
In rice plants, it is important to recognize N metabolism efficiency parameters in order to design strategies for improvements, increasing grain protein and enhancing people nutrition quality. Two rice varieties grown under humid tropic conditions were evaluated: Piaui, a landrace adapted to low N a...
| Autores: | , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2012 |
| País: | México |
| Recursos: | UNIVERSIDAD AUTÓNOMA DE YUCATÁN |
| Repositório: | Tropical and Subtropical Agroecosystems |
| Idioma: | inglês |
| OAI Identifier: | oai:ojs.www.revista.ccba.uady.mx:article/1211 |
| Acesso em linha: | https://www.revista.ccba.uady.mx/ojs/index.php/TSA/article/view/1211 |
| Access Level: | Acceso aberto |
| Palavra-chave: | plant nutrition Oryza sativa; Ammonium; V-ATPase; P-ATPase; V-PPase; GS; GOGAT; GDH Oryza sativa; amonio; V-ATPasa; P-ATPasa; V PPasa; GS; GOGAT;GDH. |
| Resumo: | In rice plants, it is important to recognize N metabolism efficiency parameters in order to design strategies for improvements, increasing grain protein and enhancing people nutrition quality. Two rice varieties grown under humid tropic conditions were evaluated: Piaui, a landrace adapted to low N availability, and reduced light supply, and IAC-47, an improved variety. The assay was carried out in controlled conditions of 24oC and 12/12 hour light/dark periods (200 µE.m-2.s-1) using a growth chamber, simulating humid tropic environment. Rice plants were grown under 0.1 and 1.0 mM NH4+-N, in a Hoagland & Arnon nutrient solution, pH 5.5, up to 26 days after germination. The activity of PM H+-ATPases in the plasma membrane, vacuole VH+-ATPases, H+-PPases as well as GS, GOGAT, and GDH were determined. PM H+-ATPase presented higher activity in IAC-47 roots. On the other hand, Piaui roots showed an enhanced microsomal protein content and VH+-ATPases activity, which apparently allows this variety to absorb N as well as the improved one. Increases in the cytosolic ammonium would result in high GDH deamination in Piaui variety at 1.0 mM NH4+-N. Meanwhile, GS increases were observed in IAC-47 shoots, together with GOGAT increases at same treatment. |
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