Abstract
Phosphate (P) starvation is one of the most limiting nutrients to N 2 fixation in legumes. Soybeans and lupins present different climatic origins, nodule morphologies and metabolic complexities, which may have various adaptive responses to short-term P starvation. Lupins and soybeans were cultivated hydroponically for 3 weeks. Short-term P starvation was induced for 14 days by switching the P-supply to 2 μM P. During P starvation, the lupins showed a lower decline in nodular P concentrations and maintained their biological N2 fixation (BNF), in contrast to the soybeans. The lupins also maintained their photosynthetic rates and the nodular construction and growth respiration costs under P starvation, whilst soybeans showed a decrease in photosynthetic rates and an increase in nodular construction and growth respiration costs under P starvation. There was a also a shift towards more organic acid synthesis, relative to amino acid synthesis in lupin nodules than soybean nodules under P starvation. The lupins had higher amino acid concentrations in their nodules, whilst the soybean nodules maintained their ureide levels at the expense of a decline in amino acids. These results indicate that lupins may to be better adapted to maintaining BNF during short-term P starvation than the soybeans.
Original language | English |
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Pages (from-to) | 102-109 |
Number of pages | 8 |
Journal | Symbiosis |
Volume | 48 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 2009 |
Externally published | Yes |
Keywords
- Carbon costs
- Lupin
- Nitrogen metabolism
- Phosphate
- Soybean
ASJC Scopus subject areas
- General Agricultural and Biological Sciences