Inhibition and recovery of symbiotic N2 fixation by peas (Pisum sativum L.) in response to short-term nitrate exposure

• Published in: Plant and soil 2011-09, Vol.346 (1-2), p.275-287
• Main Authors: Naudin, Christophe, Corre-Hellou, Guénaëlle, Voisin, Anne-Sophie, Oury, Vincent, Salon, Christophe, Crozat, Yves, Jeuffroy, Marie-Hélène
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Cropping systems; Crops; Ecology; Exposure; Flowers & plants; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Life Sciences; Mineralization; Nitrates; Nitrogen fixation; Nutrient removal; Plant Physiology; Plant Sciences; Regular Article; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Sustainable agriculture; Symbiosis
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-011-0817-8

The design of more sustainable cropping systems requires increasing N-input from symbiotic N 2 fixation (SNF). However, SNF can be inhibited by nitrate exposure (e.g., soil N-mineralization). Although the effect of nitrate on SNF has been extensively investigated at the cell scale, few studies have highlighted the impact of nitrate exposure on nodule number and biomass, nodule activity of the SNF apparatus or its ability to recover. Pea plants were grown in greenhouse conditions in a N-free nutrient solution and exposed to nitrate (5 mM NO 3 − L −1 ) for one week during either early vegetative growth, flowering or seed filling. After nitrate removal, the plants were grown either under natural light or shade. Nitrate exposure reduced the rate of nodule establishment during vegetative growth, whereas it caused damage to existing nodules when applied during the reproductive stages. Nitrate decreased the specific activity of nodules regardless of the stage of the exposure. After nitrate removal, an extra wave of nodulation was observed on plants grown under natural light but only when nitrate exposure occurred before the seed filling stage. The recovery of SNF activity after nitrate removal depended on the amount of carbon available to nodules.