Rice Ferredoxin-Dependent Glutamate Synthase Regulates Nitrogen-Carbon Metabolomes and Is Genetically Differentiated between japonica and indica Subspecies.
Plants assimilate inorganic nitrogen absorbed from soil into organic forms as Gln and Glu through the glutamine synthetase/glutamine:2-oxoglutarate amidotransferase (GS/GOGAT) cycle. Whereas GS catalyzes the formation of Gln from Glu and ammonia, GOGAT catalyzes the transfer of an amide group from Gln to 2-oxoglutarate to produce two molecules of Glu. However, the regulatory role of the GS/GOGAT cycle in the carbon-nitrogen balance is not well understood. Here, we report the functional characterization of rice ABNORMAL CYTOKININ RESPONSE 1 (ABC1) gene that encodes a ferredoxin-dependent (Fd)-GOGAT. The weak mutant allele abc1-1 mutant shows a typical nitrogen-deficient syndrome, whereas the T-DNA insertional mutant abc1-2 is seedling lethal. Metabolomics analysis revealed the accumulation of an excessive amount of amino acids with high N/C ratio (Gln and Asn) and several intermediates in the tricarboxylic acid cycle in abc1-1, suggesting that ABC1 plays a critical role in nitrogen assimilation and carbon-nitrogen balance. Five non-synonymous single-nucleotide polymorphisms were identified in the ABC1 coding region and characterized as three distinct haplotypes, which have been highly and specifically differentiated between japonica and indica subspecies. Collectively, these results suggest that ABC1/OsFd-GOGAT is essential for plant growth and development by modulating nitrogen assimilation and the carbon-nitrogen balance.
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; The University of Chinese Academy of Sciences, Beijing 100049, China.
Xiaolu
X
Yang
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Jinqiang
J
Nian
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; The University of Chinese Academy of Sciences, Beijing 100049, China.
Qingjun
Q
Xie
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; The University of Chinese Academy of Sciences, Beijing 100049, China.
Jian
J
Feng
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Fengxia
F
Zhang
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; The University of Chinese Academy of Sciences, Beijing 100049, China.
Hongwei
H
Jing
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Jian
J
Zhang
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.
Guojun
G
Dong
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Yan
Y
Liang
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Juli
J
Peng
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Guodong
G
Wang
State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China.
Qian
Q
Qian
State Key Laboratory of Plant Genomics, National Plant Gene Research Center (Beijing), CAS Center for Excellence in Molecular Plant Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: jrzuo@genetics.ac.cn.
Jianru
J
Zuo
D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D002244:Carbon / Q000378:metabolism*; D005288:Ferredoxins / Q000378:metabolism*; D055432:Metabolomics; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D013045:Species Specificity
D000596:Amino Acids; D005288:Ferredoxins; D002244:Carbon; D000594:Amino Acid Oxidoreductases; C042233:glutamate synthase (ferredoxin); D009584:Nitrogen
Fd-GOGAT; carbon–nitrogen balance; genetic variations; nitrogen assimilation; rice