Njengoba umkhiqizo waminyaka yonke ungamathani angaphezu kuka-700,000, i-glyphosate iyi-herbicide esetshenziswa kakhulu futhi enkulu kunazo zonke emhlabeni. Ukumelana nokhula kanye nezinsongo ezingaba khona endaweni ezungezile kanye nempilo yabantu okubangelwa ukusetshenziswa kabi kwe-glyphosate kuye kwadonsela ukunaka okukhulu.
Ngomhlaka-29 Meyi, ithimba likaSolwazi uGuo Ruiting elivela kwi-State Key Laboratory of Biocatalysis and Enzyme Engineering, eyasungulwa ngokubambisana yiSikole Sezesayensi Yokuphila saseHubei University kanye neminyango yesifundazwe neyongqongqoshe, lashicilela iphepha locwaningo lwakamuva ku-Journal of Hazardous Materials, lihlaziya ukuhlaziywa kokuqala kotshani be-barnyard. I-aldo-keto reductase ethathwe ku-(A malignant paddy weed) i-AKR4C16 kanye ne-AKR4C17 zivuselela indlela yokusabela kokubola kwe-glyphosate, futhi zithuthukisa kakhulu ukusebenza kahle kokubola kwe-glyphosate yi-AKR4C17 ngokuguqulwa kwama-molecule.
Ukumelana ne-glyphosate okukhula.
Kusukela yethulwa ngawo-1970, i-glyphosate ibilokhu ithandwa emhlabeni wonke, futhi kancane kancane isibe umuthi wokubulala ukhula oshibhile, osetshenziswa kakhulu futhi okhiqiza kakhulu. Ibangela ukuphazamiseka kwe-metabolic ezitshalweni, okuhlanganisa nokhula, ngokuvimbela ngqo i-5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), i-enzyme ebalulekile ehilelekile ekukhuleni kwezitshalo nasekusetshenzisweni kwe-metabolism.
Ngakho-ke, ukuzalanisa izitshalo eziguqulwe i-glyphosate ezingamelana ne-glyphosate nokusebenzisa i-glyphosate ensimini kuyindlela ebalulekile yokulawula ukhula kwezolimo zanamuhla.
Kodwa-ke, ngokusetshenziswa kabanzi kanye nokusetshenziswa kabi kwe-glyphosate, ukhula oluningi luye lwathuthuka kancane kancane futhi lwathuthukisa ukubekezelelana okuphezulu kwe-glyphosate.
Ngaphezu kwalokho, izitshalo eziguqulwe izakhi zofuzo ezingamelana ne-glyphosate azikwazi ukubola i-glyphosate, okuholela ekuqongeleleni nasekudluliselweni kwe-glyphosate ezitshalweni, okungasakazeka kalula ngochungechunge lokudla futhi kubeke impilo yabantu engozini.
Ngakho-ke, kuyaphuthuma ukuthola izakhi zofuzo ezingalimaza i-glyphosate, ukuze kutshalwe izitshalo eziguqulwe i-genic ezimelana ne-glyphosate ezinezinsalela ezincane ze-glyphosate.
Ukuxazulula isakhiwo sekristalu kanye nendlela yokusabela kwe-catalytic yama-enzyme abhubhisa i-glyphosate atholakala ezitshalweni
Ngo-2019, amaqembu ocwaningo aseShayina nase-Australia athole ama-aldo-keto reductase amabili anciphisa i-glyphosate, i-AKR4C16 kanye ne-AKR4C17, okokuqala ngqa otshanini be-barnyard obumelana ne-glyphosate. Angasebenzisa i-NADP+ njenge-cofactor yokunciphisa i-glyphosate ibe yi-aminomethylphosphonic acid engeyona enobuthi kanye ne-glyoxylic acid.
I-AKR4C16 kanye ne-AKR4C17 yizona enzyme zokuqala ezibikiwe ezibhubhisa i-glyphosate ezikhiqizwa ukuziphendukela kwemvelo kwezitshalo. Ukuze kuhlolwe kabanzi indlela yokonakala kwe-glyphosate, ithimba likaGuo Ruiting lisebenzise i-X-ray crystallography ukuhlaziya ubudlelwano phakathi kwala ma-enzyme amabili kanye ne-cofactor high. Isakhiwo esiyinkimbinkimbi sesisombululo sembule indlela yokubopha ye-ternary complex ye-glyphosate, i-NADP+ kanye ne-AKR4C17, futhi saphakamisa indlela yokusabela kwe-catalytic ye-AKR4C16 kanye ne-AKR4C17-mediated glyphosate degradation.
Isakhiwo senkimbinkimbi ye-AKR4C17/NADP+/glyphosate kanye nendlela yokusabela kokuwohloka kwe-glyphosate.
Ukuguqulwa kwama-molecule kuthuthukisa ukusebenza kahle kokuwohloka kwe-glyphosate.
Ngemva kokuthola imodeli yesakhiwo esihle esinezinhlangothi ezintathu se-AKR4C17/NADP+/glyphosate, ithimba likaSolwazi Guo Ruiting liphinde lathola iphrotheni eguquliwe i-AKR4C17F291D enokwenyuka okungu-70% ekusebenzeni kahle kokuwohloka kwe-glyphosate ngokuhlaziywa kwesakhiwo se-enzyme kanye nomklamo onengqondo.
Ukuhlaziywa komsebenzi wokonakalisa i-glyphosate wama-mutant e-AKR4C17.
“Umsebenzi wethu wembula indlela esebenza ngayo i-AKR4C16 kanye ne-AKR4C17 ekhuthaza ukuwohloka kwe-glyphosate, okubeka isisekelo esibalulekile sokuguqulwa okuqhubekayo kwe-AKR4C16 kanye ne-AKR4C17 ukuze kuthuthukiswe ukusebenza kahle kokuwohloka kwe-glyphosate.” Umbhali ohambisanayo waleli phepha, uSolwazi Ohlangene uDai Longhai wase-Hubei University uthe bakhe iphrotheni eguquliwe i-AKR4C17F291D enekhono elithuthukisiwe lokuwohloka kwe-glyphosate, elihlinzeka ngethuluzi elibalulekile lokutshala izitshalo ze-transgenic ezingamelana ne-glyphosate ezinezinsalela ze-glyphosate eziphansi kanye nokusebenzisa amabhaktheriya obunjiniyela bamagciwane ukonakalisa i-glyphosate emvelweni.
Kubikwa ukuthi ithimba likaGuo Ruiting selilokhu lihilelekile ocwaningweni lokuhlaziywa kwesakhiwo kanye nengxoxo yendlela yokusebenza kwama-enzyme okubola kwezinto eziphilayo, ama-synthases e-terpenoid, kanye namaprotheni aqondiswe ezidakamizweni zezinto ezinobuthi neziyingozi emvelweni. ULi Hao, umcwaningi ohlangene uYang Yu kanye nomfundisi uHu Yumei eqenjini bangababhali bokuqala baleli phepha, kanti uGuo Ruiting noDai Longhai bangababhali abahambisanayo.
Isikhathi sokuthunyelwe: Juni-02-2022