The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup>&...The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span><span><span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> formulations of glyphosate were investigated on the cotyledons of glyphosate resistant (GR) and glyphosate sensitive (GS) isogenic cotton cultivars. </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> is a mixture of glyphosate and 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS). Fully expanded cotton cotyledons treated with </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> or AMADS developed surface lesions within 2 hours after treatment whereas surfactant-treated control or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated tissues did not develop lesions. The </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> and AMADS damage appeared as depressions which were confirmed </span><span style="font-family:Verdana;">by scanning electron microscopy. Light micrographs of cross sections</span><span style="font-family:Verdana;"> through the depressions revealed collapsed and compressed epidermal and mesophyll cells with congealed cytoplasmic contents in the palisade and spongy mesophyll cells. Changes to photosynthetic electron transport were evident at 4 hours after treatment (HAT) in all treatments as revealed by chlorophyll A fluorescence. In GR cotton, the fluorescence perturbations decreased with time such that at 72 HAT </span></span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;">-treated cotyledons could not be distinguished from the surfactant-or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated plants. The GS cotton continued to show progressive decreases in the fluorescence parameters Fv/Fm and performance index (PI) to 72 HAT. Shikimate levels increased following glyphosate treatment in glyphosate sensitive cotton and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> caused a two-to three-fold greater increase in shikimate compared to </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">. These results indicate that the </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-based glyphosate formulation involved structural tissue damage which likely increased glyphosate uptake and subsequently increased inhibition of photosynthesis and the shikimate pathway.展开更多
文摘The effects of Roundup </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span><span><span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> formulations of glyphosate were investigated on the cotyledons of glyphosate resistant (GR) and glyphosate sensitive (GS) isogenic cotton cultivars. </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> is a mixture of glyphosate and 1-aminomethanamide dihydrogen tetraoxosulfate (AMADS). Fully expanded cotton cotyledons treated with </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> or AMADS developed surface lesions within 2 hours after treatment whereas surfactant-treated control or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated tissues did not develop lesions. The </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> and AMADS damage appeared as depressions which were confirmed </span><span style="font-family:Verdana;">by scanning electron microscopy. Light micrographs of cross sections</span><span style="font-family:Verdana;"> through the depressions revealed collapsed and compressed epidermal and mesophyll cells with congealed cytoplasmic contents in the palisade and spongy mesophyll cells. Changes to photosynthetic electron transport were evident at 4 hours after treatment (HAT) in all treatments as revealed by chlorophyll A fluorescence. In GR cotton, the fluorescence perturbations decreased with time such that at 72 HAT </span></span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;">-treated cotyledons could not be distinguished from the surfactant-or </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">-treated plants. The GS cotton continued to show progressive decreases in the fluorescence parameters Fv/Fm and performance index (PI) to 72 HAT. Shikimate levels increased following glyphosate treatment in glyphosate sensitive cotton and </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span><span><span style="font-family:Verdana;"> caused a two-to three-fold greater increase in shikimate compared to </span><span><span style="font-family:Verdana;">WeatherMax</span><sup><span style="font-family:Verdana;"><sup>®</sup></span></sup></span></span></span><span><span><span style="font-family:Verdana;">. These results indicate that the </span><span style="font-family:Verdana;">Engame<sup>TM</sup></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-based glyphosate formulation involved structural tissue damage which likely increased glyphosate uptake and subsequently increased inhibition of photosynthesis and the shikimate pathway.