Ndi mankhwala opitilira matani 700,000 pachaka, glyphosate ndiye mankhwala ophera udzu omwe amagwiritsidwa ntchito kwambiri komanso akuluakulu padziko lonse lapansi. Kukana udzu ndi zoopsa zomwe zingachitike ku chilengedwe ndi thanzi la anthu zomwe zimachitika chifukwa cha kugwiritsa ntchito glyphosate molakwika kwakopa chidwi chachikulu.
Pa Meyi 29, gulu la Pulofesa Guo Ruiting lochokera ku State Key Laboratory of Biocatalysis and Enzyme Engineering, lomwe linakhazikitsidwa pamodzi ndi School of Life Sciences of Hubei University ndi madipatimenti a chigawo ndi maunduna, linafalitsa pepala lofufuzira laposachedwa mu Journal of Hazardous Materials, kusanthula kusanthula koyamba kwa udzu wa barnyard. (A malignant paddy weed)-derived aldo-keto reductase AKR4C16 ndi AKR4C17 zimathandiza kuti glyphosate iwonongeke, komanso zimathandizira kwambiri kuti glyphosate iwonongeke bwino ndi AKR4C17 kudzera mu kusintha kwa mamolekyulu.
Kuchuluka kwa kukana kwa glyphosate.
Kuyambira pomwe idayamba kugwiritsidwa ntchito m'zaka za m'ma 1970, glyphosate yakhala yotchuka padziko lonse lapansi, ndipo pang'onopang'ono yakhala mankhwala otsika mtengo kwambiri, omwe amagwiritsidwa ntchito kwambiri komanso opindulitsa kwambiri. Imayambitsa matenda a kagayidwe kachakudya m'zomera, kuphatikizapo udzu, mwa kuletsa makamaka 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), enzyme yofunika kwambiri yomwe imakhudza kukula ndi kagayidwe kachakudya kwa zomera, komanso kufa.
Chifukwa chake, kubzala mbewu zosinthika zomwe sizikhudzidwa ndi glyphosate ndikugwiritsa ntchito glyphosate m'munda ndi njira yofunika kwambiri yowongolera udzu muulimi wamakono.
Komabe, chifukwa cha kugwiritsidwa ntchito kwambiri kwa glyphosate komanso kugwiritsa ntchito molakwika, udzu wambiri wakula pang'onopang'ono ndipo wakula kukhala ndi mphamvu zambiri zolekerera glyphosate.
Kuphatikiza apo, mbewu zosinthidwa majini zomwe sizimakhudzidwa ndi glyphosate sizingawole glyphosate, zomwe zimapangitsa kuti glyphosate isungidwe ndi kusamutsidwa m'mbewu, zomwe zimatha kufalikira mosavuta kudzera mu unyolo wa chakudya ndikuyika pachiwopsezo thanzi la anthu.
Chifukwa chake, ndikofunikira kupeza majini omwe angawononge glyphosate, kuti azitha kulima mbewu zosinthika zomwe sizimakhudzidwa ndi glyphosate zokhala ndi zotsalira zochepa za glyphosate.
Kuthetsa kapangidwe ka kristalo ndi njira yothandizira ma enzymes owononga glyphosate ochokera ku zomera
Mu 2019, magulu ofufuza aku China ndi aku Australia adapeza ma aldo-keto reductases awiri omwe amawononga glyphosate, AKR4C16 ndi AKR4C17, koyamba kuchokera ku udzu wosagonjetsedwa ndi glyphosate. Angagwiritse ntchito NADP+ ngati cofactor kuti awononge glyphosate kukhala aminomethylphosphonic acid ndi glyoxylic acid.
AKR4C16 ndi AKR4C17 ndi ma enzyme oyamba omwe amawononga glyphosate omwe amapangidwa ndi kusintha kwachilengedwe kwa zomera. Pofuna kufufuza mozama momwe ma molekyulu amawonongera glyphosate, gulu la Guo Ruiting linagwiritsa ntchito X-ray crystallography kuti liwunikire ubale pakati pa ma enzyme awiriwa ndi cofactor high. Kapangidwe kovuta ka resolution kanavumbulutsa njira yomangirira ya glyphosate, NADP+ ndi AKR4C17, ndipo adapereka njira yothanirana ndi AKR4C16 ndi AKR4C17-mediated glyphosate degradation.
Kapangidwe ka AKR4C17/NADP+/glyphosate complex ndi njira yochitira zinthu powononga glyphosate.
Kusintha kwa mamolekyulu kumathandizira kuti glyphosate igwire bwino ntchito.
Pambuyo popeza chitsanzo chabwino cha kapangidwe ka AKR4C17/NADP+/glyphosate, gulu la Pulofesa Guo Ruiting linapezanso puloteni yosinthika ya AKR4C17F291D yokhala ndi kuwonjezeka kwa 70% mu mphamvu ya kuwonongeka kwa glyphosate kudzera mu kusanthula kapangidwe ka enzyme ndi kapangidwe kabwino.
Kusanthula kwa ntchito yowononga glyphosate ya mutants ya AKR4C17.
"Ntchito yathu ikuwulula momwe mamolekyu a AKR4C16 ndi AKR4C17 amathandizira kuwonongeka kwa glyphosate, zomwe zimayika maziko ofunikira pakukonzanso kwa AKR4C16 ndi AKR4C17 kuti awonjezere mphamvu yawo yowononga glyphosate." Wolemba wogwirizana wa pepalali, Pulofesa Wachiwiri Dai Longhai wa ku Hubei University adati adapanga puloteni yosinthika ya AKR4C17F291D yokhala ndi mphamvu yowononga glyphosate, yomwe imapereka chida chofunikira cholima mbewu zosinthika zomwe sizikhudzidwa ndi glyphosate zokhala ndi zotsalira zochepa za glyphosate komanso kugwiritsa ntchito mabakiteriya a microbial engineering kuti awononge glyphosate m'chilengedwe.
Zanenedwa kuti gulu la Guo Ruiting lakhala likuchita kafukufuku wokhudza kusanthula kapangidwe kake ndi kukambirana za ma enzymes owononga chilengedwe, ma terpenoid synthases, ndi mapuloteni olimbana ndi mankhwala a zinthu zoopsa komanso zovulaza m'chilengedwe. Li Hao, wofufuza mnzake Yang Yu ndi mphunzitsi Hu Yumei m'gululi ndi omwe adalemba nawo koyamba nkhaniyi, ndipo Guo Ruiting ndi Dai Longhai ndi omwe adalemba nawo limodzi.
Nthawi yotumizira: Juni-02-2022