Interactive effects of phosphorus deficiency and exogenous auxin on root morphological and physiological traits in white lupin (Lupinus albus L.)  

作　　者：TANG HongLiang SHEN JianBo ZHANG FuSuo RENGEL Zed 

机构地区：[1]Centre for Resources, Environment and Food Security, Department of Plant Nutrition, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University [2]College of Life Science, Hebei University [3]Soil Science & Plant Nutrition, School of Earth and Environment, The University of Western Australia

出　　处：《Science China(Life Sciences)》2013年第4期313-323,共11页中国科学（生命科学英文版）

基　　金：Progress of Projects Supported by NSFC;supported by the National Natural Science Foundation of China (30925024, 30890131, 30871591);the Beijing Natural Science Foundation (6122021);the innovative group grant of NSFC (31121062);Ministry of Science and Technology of China (2013CB127402);the Innovation Fund for Graduate Student of China Agricultural University(KYCX2011040)

摘　　要：White lupin （Lupinus albus） exhibits strong root morphological and physiological responses to phosphorus （P） deficiency and auxin treatments, but the interactive effects of P and auxin in regulating root morphological and physiological traits are not fully understood. This study aimed to assess white lupin root traits as influenced by P （0 or 250 ~tmol L-1） and auxin （10=8 mol L-1 NAA） in nutrient solution. Both P deficiency and auxin treatments significantly altered root morphological traits, as evi- denced by reduced taproot length, increased number and density of first-order lateral roots, and enhanced cluster-root for- marion. Changes in root physiological traits were also observed, i.e., increased proton, citrate, and acid phosphatase exudation. Exogenous auxin enhanced root responses and sensitivity to P deficiency. A significant interplay exists between P and auxin in the regulation of root morphological and physiological traits. Principal component analysis showed that P availability ex- plained 64.8% and auxin addition 21.3% of the total variation in root trait parameters, indicating that P availability is much more important than auxin in modifying root responses of white lupin. This suggests that white lupin can coordinate root mor- phological and physiological responses to enhance acquisition of P resources, with an optimal trade-off between root morpho- logical and physiological traits regulated by external stimuli such as P availability and auxin.White lupin (Lupinus albus) exhibits strong root morphological and physiological responses to phosphorus (P) deficiency and auxin treatments, but the interactive effects of P and auxin in regulating root morphological and physiological traits are not fully understood. This study aimed to assess white lupin root traits as influenced by P (0 or 250 μmol L-1 ) and auxin (10-8 μmol L-1 NAA) in nutrient solution. Both P deficiency and auxin treatments significantly altered root morphological traits, as evidenced by reduced taproot length, increased number and density of first-order lateral roots, and enhanced cluster-root formation. Changes in root physiological traits were also observed, i.e., increased proton, citrate, and acid phosphatase exudation. Exogenous auxin enhanced root responses and sensitivity to P deficiency. A significant interplay exists between P and auxin in the regulation of root morphological and physiological traits. Principal component analysis showed that P availability explained 64.8% and auxin addition 21.3% of the total variation in root trait parameters, indicating that P availability is much more important than auxin in modifying root responses of white lupin. This suggests that white lupin can coordinate root morphological and physiological responses to enhance acquisition of P resources, with an optimal trade-off between root morphological and physiological traits regulated by external stimuli such as P availability and auxin.

关 键 词：cluster root carboxylate exudation PROTON AUXIN phosphorus deficiency Lupinus albus 

分 类 号：Q945[生物学—植物学]