Reddy Krishna N, Rimando Agnes M, Duke Stephen O, Nandula Vijay K
Southern Weed Science Research Unit, Agricultural Research Service, U.S. Department of Agriculture, P.O. Box 350, Stoneville, Mississippi 38776, USA.
J Agric Food Chem. 2008 Mar 26;56(6):2125-30. doi: 10.1021/jf072954f. Epub 2008 Feb 26.
Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels.
氨甲基膦酸（AMPA）是植物中最常检测到的草甘膦代谢物。本研究的目的是确定不同植物物种中草甘膦向AMPA的代谢与其对草甘膦的天然抗性水平之间是否存在任何相关性。进行了温室研究以确定草甘膦的I 50值（导致植物生长减少50%所需的速率），并量化以各自I 50速率用草甘膦处理的选定豆科和非豆科物种中AMPA和莽草酸的浓度。咖啡决明[Cassia occidentalis (L.) Link]对草甘膦最敏感（I 50 = 75 g/ha），而大麻田菁[Sesbania herbacea (P.Mill.) McVaugh]对草甘膦最具抗性（I 50 = 456 g/ha）。大麻田菁对草甘膦的抗性是咖啡决明的6倍，伊利诺伊束花[Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.]对草甘膦的抗性是咖啡决明的4倍。所有植物物种中都存在草甘膦，其浓度范围为0.308至38.7微克/克组织。除大麻田菁外，所有研究的豆科物种中都存在AMPA。AMPA浓度范围为0.119至4.77微克/克组织。在用草甘膦处理的所有植物物种中都存在莽草酸，其水平范围为0.053至16.5毫克/克组织。非抗草甘膦（非GR）大豆积累的莽草酸比抗草甘膦（GR）大豆高得多。虽然发现一些豆科物种比其他物种对草甘膦更具抗性，并且在所发现的草甘膦与AMPA水平之间物种间存在相当大的差异，但草甘膦向AMPA的代谢似乎不是解释天然抗性水平的共同因素。
