Study On The Resistance Of Goosegrass(Eleusine Indica L.) To Glufosinate

Goosegrass(Eleusine indica L.)is an annual monocotyledonous gramineous weed widely distributed in the northern and southern provinces of China and temperate and tropical regions of the world.Its root system is well developed,and its stalk and leaf are strong and tough.It is harmful and difficult to control in agricultural production.It is one of the top ten malignant weeds in the world.Glufosinate is an organophosphorus contact-killing herbicide,which can inhibit glutamine synthetase in the process of plant nitrogen metabolism,thus interfering with plant metabolism and causing plant death.It has wide herbicidal spectrum,low toxicity and high activity.After glyphosate was severely drug-resistant and paraquat was banned,it was more widely used in agricultural production.In 2010,the first glufosinate-resistant population of E.indica was reported in Malaysia,followed by reports in South China.In this study,two populations of E.indica and one population of Australian resistant E.indica collected from different regions in Guangdong province were used as materials.Through physiological determination of glutamine synthetase,glutamate dehydrogenase and glutamate synthase of different resistant E.indica populations,transcriptome analysis and proteome verification were carried out according to the difference between target enzyme and related enzymes under glufosinate-ammonium stress.The main results of this study are as follows :(1)The glutamate synthase(GOGAT)activity of the three tested populations decreased after application of 7 g of a.i.ha-1 glufosinate,among which the sensitive species(NX)from Zengcheng District of Guangzhou decreased from 263.63 U/g at 0 h to 68.59 U/g at 60 h;The resistant population of Eleusine indica(CS02)in Chaoshan area of Guangdong province decreased from 220.76 U/g to 132.89 U/g;Australian resistant population(AUS)decreased from 180.04 U/g to 90.02 U/g.(2)The activity of glutamate dehydrogenase(GDH)showed periodic changes in the three tested populations of Eleusine indica after application of 7 g of a.i.ha-1glufosinate,among which the sensitive population of Eleusine indica(NX)showed a large change.(3)The activity of glutamine synthetase(GS)of the three tested populations showed a downward trend after application of 7 g a.i.ha-1 glufosinate,and showed periodic changes.The enzyme activity of Australian population(AUS)was significantly higher than that of the other two populations,96.01 U/g at 0 h,1.64 times that of sensitive population(NX)and 2.8 times that of resistant population(CS02)in Chaoshan area of Guangdong.(4)The average length of the original transcriptome data is 91.29 bp.The quality of the original data is processed,and the effective reads of 6 samples are spliced by de novo.Repeating the splicing sequence,89894 transcripts with an average length of 945.00bp;were finally obtained.27326 unigenes were annotated in nr database.The six species with the largest number of unigenes were setaria italica(17.52%),panicum hallii(15.72%),panicum miliaceum(12.58%),Sorghum bicolor(9.95%),Zea mays(8.08%)and dichantheium oligosanthe.24805 unigenes were annotated into 55 GOterms under the three functional categories of go.KEGG notes map 18387 unigenes to 137 different pathways.(5)By comparing the expression of nitrogen metabolizing pathway enzymes of three different resistance to glyphosate,according to KEGG pathway map,and using Notepad + +to screen the differential CDs genes of three populations,and then to screen the GS,GDH,CA,NR,NRT differential gene sequence.Among them,there are 4 GS differential gene sequences,1 GDH differential gene sequences,1CA differential gene sequences,1 Nir A differential gene sequences To sum up,there may be different mechanisms for the resistance to glufosinate.1.Glufosinate is reduced by releasing ammonium accumulation through a large amount of transcription target enzyme GS.2.The nitrogen source is cut off by adjusting the transportation of nitric acid and nitrite reductase to nitrogen to prevent the synthesis of ammonium,thereby reducing the toxicity of ammonium and generating resistance.3.Through the double action of GDH,the toxic effect of ammonium is alleviated to some extent.4.Reduce the accumulation of ammonium in the body by reducing respiratory ammonium produced in the photosynthetic process of carbonic anhydrase.