ORGANIC ACID CHANGES IN BERMUDAGRASS ROOT EXUDATES UNDER ALUMINUM STRESS
Aluminum (Al) toxicity in acidic soils is a common problem in turfgrass areas of Oklahoma and the United States.The objective of this study was to evaluate organic acid changes of ‘Princess-77’ bermudagrass root exudates under Al stress.Replicated Al treatments were applied at 100 mg/L and 200 mg/L to bermudagrass growing in 4.5 pH sand and untreated control plants were grown in 4.5 and 7.0 pH sand.Oxalic acid accounted for 11 % of the total organic acid concentration in root tissues compared to 63% collected in root exudates,which may indicate the specific response of oxalic acid to external Al stress.Al accumulated in shoot tissues at concentrations of 1214 mg/kg and 2261 mg/kg with 100 mg/L and 200 mg/L Al treatment,respectively.There was a significant (P = 0.01) negative linear relationship (r2 = 0.61) between Al leaf accumulation and bermudagrass root mass where root mass decreased as Al accumulation increased.Oxalic acid was the dominant acid found in root exudates accounting for 51-81 % of total organic acids and the exudation rate had a significant (P = 0.01) positive linear relationship (r2 = 0.78) with external Al concentrations.Citric acid was induced by Al stress and a higher exudation rate was detected at 100 mg/L Al.The average exudation rate of malic acid also increased under Al treatment compared to the control treatments.The results indicate that organic acid exudation may play a role in Al tolerance of bermudagrass.
aluminum stress bermudagrass (Cynodon dactylon var. dactylon) citrate malate malonate organic acid oxalate root exudate succinate
Yang Tian Justin Q. Moss Niels O. Maness Bruce L. Dunn Shiping Deng Gregory E. Bell
Dept. of Horticulture and Landscape Architecture,Oklahoma State University,Stillwater,OK74078 USA Dept. of Plant and Soil Science,Oklahoma State University,Stillwater,OK 74078 USA
国际会议
The 12th International Turfgrass Research Conference(第十二届国际草坪学术大会)
北京
英文
475-483
2013-07-14（万方平台首次上网日期，不代表论文的发表时间）