Interaction between iron plaque and root border cells ameliorates aluminum toxicity of Oryza sativa differing in aluminum tolerance

• Published in: Plant and soil 2012-04, Vol.353 (1-2), p.155-167
• Main Authors: Cai, Miao-Zhen, Zhang, Shu-Na, Xing, Cheng-Hua, Wang, Fang-Mei, Zhu, Lei, Wang, Ning, Lin, Li-Yu
• Format: Article
• Language: English
• Subjects: Acid soils; Agricultural soils; Agronomy. Soil science and plant productions; Aluminum; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Cultivars; Ecology; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Iron; Life Sciences; Oryza sativa; Plant biology; Plant growth; Plant Physiology; Plant roots; Plant Sciences; Plants; Pollution tolerance; Regular Article; Rice; Root growth; Root tips; Roots; Seedlings; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Synergistic effect; Toxicity; Wetland soils
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-011-1019-0

Root border cells (RBCs), which are generated during plant growth and surround the root cap, and iron plaque (IP), ubiquitously formed on the root surfaces of rice, are known to alleviate aluminum (Al) toxicity. To verify the interactive effects of IP and RBCs on ameliorating Al toxicity, two rice cultivars differing in Al resistance were used to compare Al tolerance between cultivars. Additionally, root elongation, Al uptake and RBCs viability were measured as indicators of the effects of Al. The amounts of DCB-extractable Fe and Al on the root surfaces were much higher in the presence of IP than the absence. IP presence significantly decreased Al-induced inhibition of root elongation and Al contents in roots and root tips. The removal of RBCs from the root tips caused a more severe inhibition of root elongation and a higher Al accumulation in rice roots and root tips. Furthermore, root growth inhibition and Al contents in roots and root tips were significantly lower in roots with a combination of IP and RBCs than in roots with IP or RBCs only. The formation of IP on the root surface maintained higher RBCs viability and depressed mucilage exudation in an Al-tolerant rice cultivar. The results suggest that both IP and RBCs ameliorate Al toxicity, and IP has a greater capacity for Al resistance. The combination of IP and RBCs exhibited a synergistic effect associated with Al resistance.