The rapid detection of glyphosate resistance in goosegrass（Eleusine indica） will enhance our ability to respond to new resistant populations of this major weed. Chlorophyll fluorescence（Fluo） and P700（reaction ce...The rapid detection of glyphosate resistance in goosegrass（Eleusine indica） will enhance our ability to respond to new resistant populations of this major weed. Chlorophyll fluorescence（Fluo） and P700（reaction center chlorophyll of photosystem I） absorbance were analyzed in one biotype of goosegrass that is resistant to glyphosate and in another that remains sensitive to the herbicide. Both biotypes were treated with a foliar spray of glyphosate. Differences in photosystem II maximum quantum yield（Fv/Fm）, effective photochemical quantum yield（Y（II））, and non-photochemical quenching（NPQ） between the biotypes increased over time. Values for Fv/Fm and Y（II） differed between the two biotypes 24 h after treatment（HAT）. Differentiated activities and energy dissipation processes of photosystem II（PSII） and energy dissipation processes of photosystem I（PSI） were manifested in the two biotypes 24 HAT with 20 mmol L–1 glyphosate. Differentiated energy dissipation processes of PSI were still apparent 24 HAT with 200 mmol L–1 glyphosate. These results indicate that the Fluo parameters related to PSII activity and energy dissipation and the P700 parameters related to energy dissipation are suitable indicators that enable rapid detection of glyphosate resistance in goosegrass.展开更多
光是光合作用不可或缺的底物。然而过量的光照会对光合生物造成氧化胁迫和严重的损害。为了应对持续变化的光环境,蓝藻演化形成了灵活的电子传递网络。围绕光系统I(photosystem I,PSI)的循环电子传递(cyclic electron transport,CET)将...光是光合作用不可或缺的底物。然而过量的光照会对光合生物造成氧化胁迫和严重的损害。为了应对持续变化的光环境,蓝藻演化形成了灵活的电子传递网络。围绕光系统I(photosystem I,PSI)的循环电子传递(cyclic electron transport,CET)将电子从铁氧还蛋白Fd回流到质体醌(plastoquinone,PQ)库,产生ATP且不积累NADPH。在蓝藻和高等植物中发现了2种不同的CET途径,即NDH依赖途径和PGR5依赖途径。蓝藻中黄素二铁蛋白Flv1/Flv3参与了类梅勒(Mehler-like)反应,从PSI接受电子直接将氧气还原为水,且没有活性氧的形成。以集胞藻为试验材料,通过分析不同的CET和Flv突变株在不同光照条件下的生理特征以及其P700氧化/还原动力学,进而研究CET途径和类梅勒反应在集胞藻中的功能。结果表明NDH-1复合体对CET的贡献率超过90%,维持细胞能在持续高光环境下生长,而迅速应激的类梅勒反应在缓解瞬时高光胁迫时发挥了重要作用。因此我们认为在集胞藻中NDH-1介导的循环电子途径是稳固支持其适应高光逆境的主要机制,而类梅勒反应则是在现有主要途径严重不足时的1个备用途径。响应迅速的FLV路径是野生型和NDH-1突变株的补足。展开更多
基金supported by the Agricultural Research Project in Guangdong Province,China (2012A020100009)
文摘The rapid detection of glyphosate resistance in goosegrass（Eleusine indica） will enhance our ability to respond to new resistant populations of this major weed. Chlorophyll fluorescence（Fluo） and P700（reaction center chlorophyll of photosystem I） absorbance were analyzed in one biotype of goosegrass that is resistant to glyphosate and in another that remains sensitive to the herbicide. Both biotypes were treated with a foliar spray of glyphosate. Differences in photosystem II maximum quantum yield（Fv/Fm）, effective photochemical quantum yield（Y（II））, and non-photochemical quenching（NPQ） between the biotypes increased over time. Values for Fv/Fm and Y（II） differed between the two biotypes 24 h after treatment（HAT）. Differentiated activities and energy dissipation processes of photosystem II（PSII） and energy dissipation processes of photosystem I（PSI） were manifested in the two biotypes 24 HAT with 20 mmol L–1 glyphosate. Differentiated energy dissipation processes of PSI were still apparent 24 HAT with 200 mmol L–1 glyphosate. These results indicate that the Fluo parameters related to PSII activity and energy dissipation and the P700 parameters related to energy dissipation are suitable indicators that enable rapid detection of glyphosate resistance in goosegrass.
基金Elite Youth Program of Chinese Academy of Agricultural Sciences and the Agricultural Science and Technology Innovation Program。
文摘光是光合作用不可或缺的底物。然而过量的光照会对光合生物造成氧化胁迫和严重的损害。为了应对持续变化的光环境,蓝藻演化形成了灵活的电子传递网络。围绕光系统I(photosystem I,PSI)的循环电子传递(cyclic electron transport,CET)将电子从铁氧还蛋白Fd回流到质体醌(plastoquinone,PQ)库,产生ATP且不积累NADPH。在蓝藻和高等植物中发现了2种不同的CET途径,即NDH依赖途径和PGR5依赖途径。蓝藻中黄素二铁蛋白Flv1/Flv3参与了类梅勒(Mehler-like)反应,从PSI接受电子直接将氧气还原为水,且没有活性氧的形成。以集胞藻为试验材料,通过分析不同的CET和Flv突变株在不同光照条件下的生理特征以及其P700氧化/还原动力学,进而研究CET途径和类梅勒反应在集胞藻中的功能。结果表明NDH-1复合体对CET的贡献率超过90%,维持细胞能在持续高光环境下生长,而迅速应激的类梅勒反应在缓解瞬时高光胁迫时发挥了重要作用。因此我们认为在集胞藻中NDH-1介导的循环电子途径是稳固支持其适应高光逆境的主要机制,而类梅勒反应则是在现有主要途径严重不足时的1个备用途径。响应迅速的FLV路径是野生型和NDH-1突变株的补足。
