Details
Original language | English |
---|---|
Pages (from-to) | 909-926 |
Number of pages | 18 |
Journal | Plant Journal |
Volume | 55 |
Issue number | 6 |
Publication status | Published - 1 Sept 2008 |
Externally published | Yes |
Abstract
The application of nitrogen to legumes regulates seed metabolism and composition. We recently showed that the seed-specific overexpression of amino acid permease VfAAP1 increases amino acid supply, and the levels of N and protein in the seeds. Two consecutive field trials using Pisum sativum AAP1 lines confirmed increases in the levels of N and globulin in seed; however, compensatory changes of sucrose/starch and individual seed weight were also observed. We present a comprehensive analysis of AAP1 seeds using combinatorial transcript and metabolite profiling to monitor the effects of nitrogen supply on seed metabolism. AAP1 seeds have increased amino acids and stimulated gene expression associated with storage protein synthesis, maturation, deposition and vesicle trafficking. Transcript/metabolite changes reveal the channelling of surplus N into the transient storage pools asparagine and arginine, indicating that asparagine synthase is transcriptionally activated by high N levels and/or C limitation. Increased C-acceptor demand for amino acid synthesis, resulting from elevated levels of N in seeds, initiates sucrose mobilization and sucrose-dependent pathways via sucrose synthase, glycolysis and the TCA cycle. The AAP1 seeds display a limitation in C, which leads to the catabolism of arginine, glutamic acid and methionine to putrescine, β-alanine and succinate. Mitochondria are involved in the coordination of C/N metabolism, with branched-chain amino acid catabolism and a γ-amino-butyric acid shunt. AAP1 seeds contain higher levels of ABA, which is possibly involved in storage-associated gene expression and the N-dependent stimulation of sucrose mobilization, indicating that a signalling network of C, N and ABA is operating during seed maturation. These results demonstrate that legume seeds have a high capacity to regulate N:C ratios, and highlight the importance of mitochondria in the control of N-C balance and amino acid homeostasis.
Keywords
- Amino acid metabolism, C/N interaction, Legume seed maturation, Metabolic regulation, Mitochondria, Nitrogen
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Genetics
- Agricultural and Biological Sciences(all)
- Plant Science
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Plant Journal, Vol. 55, No. 6, 01.09.2008, p. 909-926.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Increasing amino acid supply in pea embryos reveals specific interactions of N and C metabolism, and highlights the importance of mitochondrial metabolism
AU - Weigelt, Kathleen
AU - Küster, Helge
AU - Radchuk, Ruslana
AU - Müller, Martin
AU - Weichert, Heiko
AU - Fait, Aaron
AU - Fernie, Alisdair R.
AU - Saalbach, Isolde
AU - Weber, Hans
PY - 2008/9/1
Y1 - 2008/9/1
N2 - The application of nitrogen to legumes regulates seed metabolism and composition. We recently showed that the seed-specific overexpression of amino acid permease VfAAP1 increases amino acid supply, and the levels of N and protein in the seeds. Two consecutive field trials using Pisum sativum AAP1 lines confirmed increases in the levels of N and globulin in seed; however, compensatory changes of sucrose/starch and individual seed weight were also observed. We present a comprehensive analysis of AAP1 seeds using combinatorial transcript and metabolite profiling to monitor the effects of nitrogen supply on seed metabolism. AAP1 seeds have increased amino acids and stimulated gene expression associated with storage protein synthesis, maturation, deposition and vesicle trafficking. Transcript/metabolite changes reveal the channelling of surplus N into the transient storage pools asparagine and arginine, indicating that asparagine synthase is transcriptionally activated by high N levels and/or C limitation. Increased C-acceptor demand for amino acid synthesis, resulting from elevated levels of N in seeds, initiates sucrose mobilization and sucrose-dependent pathways via sucrose synthase, glycolysis and the TCA cycle. The AAP1 seeds display a limitation in C, which leads to the catabolism of arginine, glutamic acid and methionine to putrescine, β-alanine and succinate. Mitochondria are involved in the coordination of C/N metabolism, with branched-chain amino acid catabolism and a γ-amino-butyric acid shunt. AAP1 seeds contain higher levels of ABA, which is possibly involved in storage-associated gene expression and the N-dependent stimulation of sucrose mobilization, indicating that a signalling network of C, N and ABA is operating during seed maturation. These results demonstrate that legume seeds have a high capacity to regulate N:C ratios, and highlight the importance of mitochondria in the control of N-C balance and amino acid homeostasis.
AB - The application of nitrogen to legumes regulates seed metabolism and composition. We recently showed that the seed-specific overexpression of amino acid permease VfAAP1 increases amino acid supply, and the levels of N and protein in the seeds. Two consecutive field trials using Pisum sativum AAP1 lines confirmed increases in the levels of N and globulin in seed; however, compensatory changes of sucrose/starch and individual seed weight were also observed. We present a comprehensive analysis of AAP1 seeds using combinatorial transcript and metabolite profiling to monitor the effects of nitrogen supply on seed metabolism. AAP1 seeds have increased amino acids and stimulated gene expression associated with storage protein synthesis, maturation, deposition and vesicle trafficking. Transcript/metabolite changes reveal the channelling of surplus N into the transient storage pools asparagine and arginine, indicating that asparagine synthase is transcriptionally activated by high N levels and/or C limitation. Increased C-acceptor demand for amino acid synthesis, resulting from elevated levels of N in seeds, initiates sucrose mobilization and sucrose-dependent pathways via sucrose synthase, glycolysis and the TCA cycle. The AAP1 seeds display a limitation in C, which leads to the catabolism of arginine, glutamic acid and methionine to putrescine, β-alanine and succinate. Mitochondria are involved in the coordination of C/N metabolism, with branched-chain amino acid catabolism and a γ-amino-butyric acid shunt. AAP1 seeds contain higher levels of ABA, which is possibly involved in storage-associated gene expression and the N-dependent stimulation of sucrose mobilization, indicating that a signalling network of C, N and ABA is operating during seed maturation. These results demonstrate that legume seeds have a high capacity to regulate N:C ratios, and highlight the importance of mitochondria in the control of N-C balance and amino acid homeostasis.
KW - Amino acid metabolism
KW - C/N interaction
KW - Legume seed maturation
KW - Metabolic regulation
KW - Mitochondria
KW - Nitrogen
UR - http://www.scopus.com/inward/record.url?scp=51249109670&partnerID=8YFLogxK
U2 - 10.1111/j.1365-313X.2008.03560.x
DO - 10.1111/j.1365-313X.2008.03560.x
M3 - Article
C2 - 18494854
AN - SCOPUS:51249109670
VL - 55
SP - 909
EP - 926
JO - Plant Journal
JF - Plant Journal
SN - 0960-7412
IS - 6
ER -