Nitrogen Fixation by White Lupin under Phosphorus Deficiency

摘要: • Background and Aims White lupin is highly adapted to growth in a low-P environment. The objective of the present study was evaluate whether white grown under P-stress has adaptations nodulation N2 fixation that facilitate continued functioning. • Methods Nodulated plants were silica sand supplied with N-free nutrient solution containing 0 0·5 mm P. At 21 37 d after inoculation (DAI) growth, nodulation, P N concentration, (15N2 uptake H2 evolution), root/nodule net CO2 evolution (14CO2 uptake) measured. Furthermore, at DAI in-vitro activities transcript abundance key enzymes C metabolism nodules determined. Moreover, cluster root zones evaluated. • Key Results Treatment without led lower concentration shoots, roots, nodules. In both treatments, or P, greater than other organs. nitrogen rates did not differ between treatments displayed no symptoms deficiency on their shoots. Although nodule number increased response P-deficiency, total mass remained constant. Increased P-deficient associated formation. A higher treatment release per unit fixed N, although released correlated enzyme phosphoenolpyruvate carboxylase malate dehydrogenase Between 37 DAI, shoots developed N- P-deficiency. By had decreased all organs treated almost ceased. • Conclusions Enhanced potential for organic acid production appear contribute lupin's resilience