Root Exudates of Rice Cultivars Affect Rhizospheric Phosphorus Dynamics in Soils with Different Phosphorus Statuses

• Published in: Communications in Soil Science and Plant Analysis Vol. 44; no. 10; pp. 1643 - 1658
• Main Authors: Bhattacharyya, P., Das, S., Adhya, T. K.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis 31-05-2013; Taylor & Francis Ltd
• Subjects: Acids; Agronomy. Soil science and plant productions; Biological and medical sciences; Crop science; Cultivars; Fundamental and applied biological sciences. Psychology; Organic acids; P dynamics; Rice; rice rhizosphere; root exudates; Soil science; Monocotyledones; Exudate; P dynamics; Root; Phosphorus; Biogeochemical cycle; Cereal crop; Organic acids; Oryza sativa; Rhizosphere; Soils; Gramineae; Phosphorus cycle; Angiospermae; rice rhizosphere; root exudates; Spermatophyta; Cultivar
• ISSN: 0010-3624; 1532-2416; 1532-4133
• DOI: 10.1080/00103624.2013.769562

Exudation of organic acids by the roots of three rice cultivars grown in three soils of different phosphorus (P) statuses, and their impacts on the rhizospheric P dynamics and P uptake by the rice plants, were investigated. Quantum root exudates from all the rice cultivars were significantly greater at 21 days after transplantation than at panicle initiation or flowering stages. Malic acid was the most predominant organic acid present in the rice root exudates (10.3 to 89.5 μmol plant
−1
d
−1
), followed by tartaric, citric, and acetic acids. Greater exudation of organic acids from rice grown in P-deficient soil by all the rice cultivars suggested response of rice plant to P stress. Results indicate that the release of organic acids in the root exudates of rice plants can extract P from strongly adsorbed soil P fraction, thereby increasing native soil P utilization efficiency and ensuring adequate P nutrition for the growing rice plants.