Keng stiffgrass is a grass weed that affects wheat-rice cropping systems in China. The extensive reliance on acetyl coen- zyme A carboxylase （ACCase）-inhibiting herbicides has resulted in keng stiffgrass developing ...Keng stiffgrass is a grass weed that affects wheat-rice cropping systems in China. The extensive reliance on acetyl coen- zyme A carboxylase （ACCase）-inhibiting herbicides has resulted in keng stiffgrass developing resistance to these herbicides. The objective of this research was to evaluate the resistance level of the putative resistant keng stiffgrass populations to ACCase-inhibiting herbicides and to identify their molecular resistance mechanism. Whole-plant dose-response experi- ments demonstrated that SD-4 （R）, SD-11 （R）, and JS-25 （R） populations were highly resistant to fenoxaprop, clodinafop, and fluazifop, moderately resistant to diclofop, had low resistance to sethoxydim and pinoxaden, but were sensitive to clethodim. Partial chloroplasticACCase sequences showed that there were two copies ofACCase gene in keng stiffgrass, and all homoeologous genes were expressed. The results of sequence analyses of the ACCase CT domain revealed an isoleucine-to-asparagine substitution at position 2041 in SD-4 （R） and SD-11 （R） populations, and a tryptophan-to-cysteine substitution at position 2027 in the JS-25 （R） population. To our knowledge, this is the first report of Ile-2041-Asn and Trp- 2027-Cys mutations in ACCase-resistant keng stiffgrass. In addition, three robust （derived） cleaved amplified polymorphic sequence （（d）CAPS） markers have been developed to rapidly identify these mutations in the ACCase gene of keng stiffgrass.展开更多
Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase(EPSPS)and overexpression of the EPSPS gene is one of the molecular mechanisms conferring glyphosate resistance in weeds.A regulatory sequence ...Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase(EPSPS)and overexpression of the EPSPS gene is one of the molecular mechanisms conferring glyphosate resistance in weeds.A regulatory sequence of EPSPS gene was isolated previously,and an alteration in its 5´-untranslated region(UTR)pyrimidine(Py)-rich stretch element is involved in the regulation of EPSPS expression in glyphosate-resistant(GR)Eleusine indica.However,the transcription factors involved in this regulatory sequence remain to be elucidated.In this study,we investigated the regulatory network of EPSPS overexpression associated genes in a GR E.indica population by RNA-seq.The differentially expressed transcript analyses revealed that glyphosate treatment caused an increase in the expression of 2752 unigenes and a decrease in the expression of 4025 unigenes in the GR E.indica,compared to the glyphosatesusceptible(GS)E.indica.Among them,1373 unigenes were identified to be co-expressed with the EPSPS gene in GR E.indica.GO and KEGG pathway analyses showed that the up-regulated unigenes were mainly enriched in chloroplasts and associated with the shikimate biosynthesis pathway,chlorophy II and peroxisome metabolism processes.Notably,the expression of a Shikimate kinase which catalyzed the conversion of Shikimate to Shikimate 3-phosphate(S3P,a substrate of EPSPS),was also up-regulated.Eight transcription factors were identified as likely to be involved in the regulation of the EPSPS expression,and three of them(ARF2,ARF8 and BPC6)showed more binding sites because of a(CT)n insertion of the 5´-UTR Py-rich stretch element in GR.However,the yeast one-hybrid assay illustrated that ARF8 and BPC6 could bind to the 5´-UTR Py-rich stretch element of wild type EPSPS,but could not bind to the mutated form.Our data suggests that the transcriptional regulation of EPSPS expression is complex and was significantly altered in GR E.indica.These discoveries provide new references for further study of the EPSPS overexpression mechanism that endows glyphosate resistance.展开更多
研究30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米田的应用效果,在甜玉米不同叶龄期开展田间试验,评价其对杂草的防除效果及对甜玉米的安全性。结果表明,30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米...研究30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米田的应用效果,在甜玉米不同叶龄期开展田间试验,评价其对杂草的防除效果及对甜玉米的安全性。结果表明,30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米3~4叶期或6~7叶期施药,900~1575 g a.i./hm^2剂量范围内对甜玉米品种粤甜28安全,对玉米田常见杂草凹头苋、光头稗、马唐和香附子的防效及增产效果均显著高于对照药剂38%莠去津悬浮剂2160 g a.i./hm^2播后苗前处理。推荐30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在900~1350 g a.i./hm^2范围内,甜玉米3~5叶期茎叶喷雾使用。展开更多
基金financially supported by the Special Fund for Agro-scientific Research in the Public Interest,China(201303031)the National Natural Science Foundation of China(31471787)
文摘Keng stiffgrass is a grass weed that affects wheat-rice cropping systems in China. The extensive reliance on acetyl coen- zyme A carboxylase （ACCase）-inhibiting herbicides has resulted in keng stiffgrass developing resistance to these herbicides. The objective of this research was to evaluate the resistance level of the putative resistant keng stiffgrass populations to ACCase-inhibiting herbicides and to identify their molecular resistance mechanism. Whole-plant dose-response experi- ments demonstrated that SD-4 （R）, SD-11 （R）, and JS-25 （R） populations were highly resistant to fenoxaprop, clodinafop, and fluazifop, moderately resistant to diclofop, had low resistance to sethoxydim and pinoxaden, but were sensitive to clethodim. Partial chloroplasticACCase sequences showed that there were two copies ofACCase gene in keng stiffgrass, and all homoeologous genes were expressed. The results of sequence analyses of the ACCase CT domain revealed an isoleucine-to-asparagine substitution at position 2041 in SD-4 （R） and SD-11 （R） populations, and a tryptophan-to-cysteine substitution at position 2027 in the JS-25 （R） population. To our knowledge, this is the first report of Ile-2041-Asn and Trp- 2027-Cys mutations in ACCase-resistant keng stiffgrass. In addition, three robust （derived） cleaved amplified polymorphic sequence （（d）CAPS） markers have been developed to rapidly identify these mutations in the ACCase gene of keng stiffgrass.
基金This study was supported by the National Natural Science Foundation of China(31871984)the Guangdong Provincial National Natural Science Foundation,China(2017B030311006)+1 种基金the Department of Science and Technology of Guangdong Province,China(2019B121201003)the special fund for Scientific Innovation Strategy-Construction of High Level Academy of Agriculture Science,China(202105TD,R2020PYJX005).
文摘Glyphosate inhibits the enzyme 5-enolpyruvylshikimate-3-phosphate synthase(EPSPS)and overexpression of the EPSPS gene is one of the molecular mechanisms conferring glyphosate resistance in weeds.A regulatory sequence of EPSPS gene was isolated previously,and an alteration in its 5´-untranslated region(UTR)pyrimidine(Py)-rich stretch element is involved in the regulation of EPSPS expression in glyphosate-resistant(GR)Eleusine indica.However,the transcription factors involved in this regulatory sequence remain to be elucidated.In this study,we investigated the regulatory network of EPSPS overexpression associated genes in a GR E.indica population by RNA-seq.The differentially expressed transcript analyses revealed that glyphosate treatment caused an increase in the expression of 2752 unigenes and a decrease in the expression of 4025 unigenes in the GR E.indica,compared to the glyphosatesusceptible(GS)E.indica.Among them,1373 unigenes were identified to be co-expressed with the EPSPS gene in GR E.indica.GO and KEGG pathway analyses showed that the up-regulated unigenes were mainly enriched in chloroplasts and associated with the shikimate biosynthesis pathway,chlorophy II and peroxisome metabolism processes.Notably,the expression of a Shikimate kinase which catalyzed the conversion of Shikimate to Shikimate 3-phosphate(S3P,a substrate of EPSPS),was also up-regulated.Eight transcription factors were identified as likely to be involved in the regulation of the EPSPS expression,and three of them(ARF2,ARF8 and BPC6)showed more binding sites because of a(CT)n insertion of the 5´-UTR Py-rich stretch element in GR.However,the yeast one-hybrid assay illustrated that ARF8 and BPC6 could bind to the 5´-UTR Py-rich stretch element of wild type EPSPS,but could not bind to the mutated form.Our data suggests that the transcriptional regulation of EPSPS expression is complex and was significantly altered in GR E.indica.These discoveries provide new references for further study of the EPSPS overexpression mechanism that endows glyphosate resistance.
文摘研究30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米田的应用效果,在甜玉米不同叶龄期开展田间试验,评价其对杂草的防除效果及对甜玉米的安全性。结果表明,30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米3~4叶期或6~7叶期施药,900~1575 g a.i./hm^2剂量范围内对甜玉米品种粤甜28安全,对玉米田常见杂草凹头苋、光头稗、马唐和香附子的防效及增产效果均显著高于对照药剂38%莠去津悬浮剂2160 g a.i./hm^2播后苗前处理。推荐30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在900~1350 g a.i./hm^2范围内,甜玉米3~5叶期茎叶喷雾使用。
