Changes in nitrogen assimilation, metabolism, and growth in transgenic rice plants expressing a fungal NADP(H)-dependent glutamate dehydrogenase (gdhA)

Tomomi Abiko, Masataka Wakayama, Akira Kawakami, Mitsuhiro Obara, Hiroaki Kisaka, Tetsuya Miwa, Naohiro Aoki, Ryu Ohsugi

研究成果: ジャーナルへの寄稿記事

38 引用 (Scopus)

抄録

In plants, glutamine synthetase (GS) is the enzyme that is mainly responsible for the assimilation of ammonium. Conversely, in microorganisms such as bacteria and Ascomycota, NADP(H)-dependent glutamate dehydrogenase (GDH) and GS both have important roles in ammonium assimilation. Here, we report the changes in nitrogen assimilation, metabolism, growth, and grain yield of rice plants caused by an ectopic expression of NADP(H)-GDH (gdhA) from the fungus Aspergillus niger in the cytoplasm. An investigation of the kinetic properties of purified recombinant protein showed that the fungal gdhA had 5.4-10.2 times higher Vmax value and 15.9-43.1 times higher Km value for NH4+, compared with corresponding values for rice cytosolic GS as reported in the literature. These results suggested that the introduction of fungal GDH into rice could modify its ammonium assimilation pathway. We therefore expressed gdhA in the cytoplasm of rice plants. NADP(H)-GDH activities in the gdhA-transgenic lines were markedly higher than those in a control line. Tracer experiments by feeding with 15NH4+ showed that the introduced gdhA, together with the endogenous GS, directly assimilated NH4+ absorbed from the roots. Furthermore, in comparison with the control line, the transgenic lines showed an increase in dry weight and nitrogen content when sufficient nitrogen was present, but did not do so under low-nitrogen conditions. Under field condition, the transgenic line examined showed a significant increase in grain yield in comparison with the control line. These results suggest that the introduction of fungal gdhA into rice plants could lead to better growth and higher grain yield by enhancing the assimilation of ammonium.

元の言語英語
ページ(範囲)299-311
ページ数13
ジャーナルPlanta
232
発行部数2
DOI
出版物ステータス出版済み - 7 1 2010
外部発表Yes

Fingerprint

Glutamate Dehydrogenase (NADP+)
Glutamate Dehydrogenase
glutamate dehydrogenase
Genetically Modified Plants
assimilation (physiology)
Nitrogen
genetically modified organisms
Glutamate-Ammonia Ligase
rice
metabolism
Ammonium Compounds
nitrogen
Growth
glutamate-ammonia ligase
Cytoplasm
grain yield
Ascomycota
Aspergillus niger
cytoplasm
Oryza

All Science Journal Classification (ASJC) codes

  • Genetics
  • Plant Science

これを引用

Changes in nitrogen assimilation, metabolism, and growth in transgenic rice plants expressing a fungal NADP(H)-dependent glutamate dehydrogenase (gdhA). / Abiko, Tomomi; Wakayama, Masataka; Kawakami, Akira; Obara, Mitsuhiro; Kisaka, Hiroaki; Miwa, Tetsuya; Aoki, Naohiro; Ohsugi, Ryu.

:: Planta, 巻 232, 番号 2, 01.07.2010, p. 299-311.

研究成果: ジャーナルへの寄稿記事

Abiko, Tomomi ; Wakayama, Masataka ; Kawakami, Akira ; Obara, Mitsuhiro ; Kisaka, Hiroaki ; Miwa, Tetsuya ; Aoki, Naohiro ; Ohsugi, Ryu. / Changes in nitrogen assimilation, metabolism, and growth in transgenic rice plants expressing a fungal NADP(H)-dependent glutamate dehydrogenase (gdhA). :: Planta. 2010 ; 巻 232, 番号 2. pp. 299-311.
@article{50514837a01541218997990141b0c620,
title = "Changes in nitrogen assimilation, metabolism, and growth in transgenic rice plants expressing a fungal NADP(H)-dependent glutamate dehydrogenase (gdhA)",
abstract = "In plants, glutamine synthetase (GS) is the enzyme that is mainly responsible for the assimilation of ammonium. Conversely, in microorganisms such as bacteria and Ascomycota, NADP(H)-dependent glutamate dehydrogenase (GDH) and GS both have important roles in ammonium assimilation. Here, we report the changes in nitrogen assimilation, metabolism, growth, and grain yield of rice plants caused by an ectopic expression of NADP(H)-GDH (gdhA) from the fungus Aspergillus niger in the cytoplasm. An investigation of the kinetic properties of purified recombinant protein showed that the fungal gdhA had 5.4-10.2 times higher Vmax value and 15.9-43.1 times higher Km value for NH4+, compared with corresponding values for rice cytosolic GS as reported in the literature. These results suggested that the introduction of fungal GDH into rice could modify its ammonium assimilation pathway. We therefore expressed gdhA in the cytoplasm of rice plants. NADP(H)-GDH activities in the gdhA-transgenic lines were markedly higher than those in a control line. Tracer experiments by feeding with 15NH4+ showed that the introduced gdhA, together with the endogenous GS, directly assimilated NH4+ absorbed from the roots. Furthermore, in comparison with the control line, the transgenic lines showed an increase in dry weight and nitrogen content when sufficient nitrogen was present, but did not do so under low-nitrogen conditions. Under field condition, the transgenic line examined showed a significant increase in grain yield in comparison with the control line. These results suggest that the introduction of fungal gdhA into rice plants could lead to better growth and higher grain yield by enhancing the assimilation of ammonium.",
author = "Tomomi Abiko and Masataka Wakayama and Akira Kawakami and Mitsuhiro Obara and Hiroaki Kisaka and Tetsuya Miwa and Naohiro Aoki and Ryu Ohsugi",
year = "2010",
month = "7",
day = "1",
doi = "10.1007/s00425-010-1172-3",
language = "English",
volume = "232",
pages = "299--311",
journal = "Planta",
issn = "0032-0935",
publisher = "Springer Verlag",
number = "2",

}

TY - JOUR

T1 - Changes in nitrogen assimilation, metabolism, and growth in transgenic rice plants expressing a fungal NADP(H)-dependent glutamate dehydrogenase (gdhA)

AU - Abiko, Tomomi

AU - Wakayama, Masataka

AU - Kawakami, Akira

AU - Obara, Mitsuhiro

AU - Kisaka, Hiroaki

AU - Miwa, Tetsuya

AU - Aoki, Naohiro

AU - Ohsugi, Ryu

PY - 2010/7/1

Y1 - 2010/7/1

N2 - In plants, glutamine synthetase (GS) is the enzyme that is mainly responsible for the assimilation of ammonium. Conversely, in microorganisms such as bacteria and Ascomycota, NADP(H)-dependent glutamate dehydrogenase (GDH) and GS both have important roles in ammonium assimilation. Here, we report the changes in nitrogen assimilation, metabolism, growth, and grain yield of rice plants caused by an ectopic expression of NADP(H)-GDH (gdhA) from the fungus Aspergillus niger in the cytoplasm. An investigation of the kinetic properties of purified recombinant protein showed that the fungal gdhA had 5.4-10.2 times higher Vmax value and 15.9-43.1 times higher Km value for NH4+, compared with corresponding values for rice cytosolic GS as reported in the literature. These results suggested that the introduction of fungal GDH into rice could modify its ammonium assimilation pathway. We therefore expressed gdhA in the cytoplasm of rice plants. NADP(H)-GDH activities in the gdhA-transgenic lines were markedly higher than those in a control line. Tracer experiments by feeding with 15NH4+ showed that the introduced gdhA, together with the endogenous GS, directly assimilated NH4+ absorbed from the roots. Furthermore, in comparison with the control line, the transgenic lines showed an increase in dry weight and nitrogen content when sufficient nitrogen was present, but did not do so under low-nitrogen conditions. Under field condition, the transgenic line examined showed a significant increase in grain yield in comparison with the control line. These results suggest that the introduction of fungal gdhA into rice plants could lead to better growth and higher grain yield by enhancing the assimilation of ammonium.

AB - In plants, glutamine synthetase (GS) is the enzyme that is mainly responsible for the assimilation of ammonium. Conversely, in microorganisms such as bacteria and Ascomycota, NADP(H)-dependent glutamate dehydrogenase (GDH) and GS both have important roles in ammonium assimilation. Here, we report the changes in nitrogen assimilation, metabolism, growth, and grain yield of rice plants caused by an ectopic expression of NADP(H)-GDH (gdhA) from the fungus Aspergillus niger in the cytoplasm. An investigation of the kinetic properties of purified recombinant protein showed that the fungal gdhA had 5.4-10.2 times higher Vmax value and 15.9-43.1 times higher Km value for NH4+, compared with corresponding values for rice cytosolic GS as reported in the literature. These results suggested that the introduction of fungal GDH into rice could modify its ammonium assimilation pathway. We therefore expressed gdhA in the cytoplasm of rice plants. NADP(H)-GDH activities in the gdhA-transgenic lines were markedly higher than those in a control line. Tracer experiments by feeding with 15NH4+ showed that the introduced gdhA, together with the endogenous GS, directly assimilated NH4+ absorbed from the roots. Furthermore, in comparison with the control line, the transgenic lines showed an increase in dry weight and nitrogen content when sufficient nitrogen was present, but did not do so under low-nitrogen conditions. Under field condition, the transgenic line examined showed a significant increase in grain yield in comparison with the control line. These results suggest that the introduction of fungal gdhA into rice plants could lead to better growth and higher grain yield by enhancing the assimilation of ammonium.

UR - http://www.scopus.com/inward/record.url?scp=77955684963&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77955684963&partnerID=8YFLogxK

U2 - 10.1007/s00425-010-1172-3

DO - 10.1007/s00425-010-1172-3

M3 - Article

C2 - 20443025

AN - SCOPUS:77955684963

VL - 232

SP - 299

EP - 311

JO - Planta

JF - Planta

SN - 0032-0935

IS - 2

ER -