Cng ngh bin i gen thc vt. ng dng thc phm bin i gen trong lnh vc thc phm
TIU LUN CNG NGH BIN I GEN THC VTNG DNG CA THC VT BIN I GEN TRONG LNH VC THC PHMGing vin hng dn: TS. TRN BCH LAMHc vin thc hin: TH THANH LOAN 13111015 NGUYN TH VINH 13111035
Thnh ph H Ch Minh, thng 5 nm 2014
MN: HA SINH THC PHMTRNG I HC BCH KHOAKHOA K THUT HA HC
Cng ngh bin i gen thc vt. ng dng thc phm bin i gen trong lnh vc thc phm
MC LC
1. Gii thiu chung42. Cc khi nim42.1 Khi nim thc vt bin i gen (thc vt chuyn gen)42.2 Cng ngh bin i gen43. K thut chuyn gen53.1 Nguyn tc sinh hc ca k thut chuyn gen53.2 Cc bc trong k thut chuyn gen54. Cc phng php chuyn gen thc vt64.1 Cc phng php chuyn gen gin tip64.1.1 chuyn gen gin tip nh Agrobacterium tunefaciens64.1.2 Chuyn gen gin tip nh virus84.2 Cc phng php chuyn gen trc tip94.2.1 Chuyn gen bng sng bn gen94.2.2 Chuyn gen bng k thut xung in114.2.3 Chuyn gen bng vi tim134.2.4 Chuyn gen nh k thut siu m134.2.5 Chuyn gen bng phng php ha hc144.2.6 Chuyn gen trc tip qua ng phn144.2.7 Chuyn gen trc tip vo protoplast155. Li ch, nguy c ca v hin trng s dng ca cy trng bin i gen165.1 Nhng li ch ca cy trng bin i gen165.2 Nhng tc hi tim tng ca cy trng bin i gen185.3 Hin trng v xu hng pht trin cy trng bin i gen trn th gii196. Cc hng chnh trong thc vt chuyn gen206.1 chuyn gen khng su bnh206.2 Chuyn gen khng thuc dit c216.3 Chuyn gen to cy khng virus gy bnh226.4 chuyn gen to cy sn xut protein ng vt226.5 chuyn gen lm thay i hm lng v cht dinh dng ca cy236.6 chuyn gen to ging hoa c mu sc mi237. Mt s ng dng ca thc vt chuyn gen trong cng ngh thc phm247.1 Cy ng247.2 Cy u nnh257.3. Bng267.4. u 277.5 Cy la287.6 Cy ci du297.7 Khoai ty317.8 C chua337.9 Sn phm t sa357.10 u H Lan368. Kt lun37TI LIU KHAM KHO38
1. Gii thiu chung Trc y, to mt ging mi cc nh to ging thng s dng phng php truyn thng t hp li cc gen gia hai c th thc vt to ra con lai mang nhng tnh trng mong mun. Phng php ny c thc hin bng cch chuyn ht phn t cy ny sang nhy hoa ca cy khc. Tuy nhin, php lai cho ny b hn ch bi n ch c th thc hin c gia cc c th cng loi (lai gn), lai gia nhng cc th khc loi (lai xa) thng b bt th do khng th to ra con lai c. Tuy nhin, lai gn cng phi mt nhiu thi gian mi thu c nhng kt qu mong mun v thng thng nhng tnh trng quan tm li khng tn ti trong nhng loi c h hng gn nhau.
Ngy nay, cng ngh chuyn gen cho php nh to ging cng lc a vo mt loi cy trng nhng gen mong mun c ngun gc t nhng c th sng khc nhau, khng ch gia cc loi c h gn nhau m cn nhng loi rt xa nhau. l cy trng bin i gen (cy trng chuyn gen).
2. Cc khi nim2.1 Khi nim thc vt bin i gen (thc vt chuyn gen) Thc vt bin i gen l l thc vt m vt liu di truyn ca n c bin i theo mun ch quan ca con ngi. N mang mt t hp nguyn liu di truyn mi to ra nh cng ngh bin i gen (cng ngh chuyn gen).
Thc vt bin i gen c a vo mt hay nhiu gen. Nhng gen c a vo (gen chuyn) c th c phn lp t nhng loi c quan h h hng hay t nhng loi khc bit hon ton.
2.2 Cng ngh bin i gen Cng ngh bin i gen l cng ngh chuyn gen theo k thut DNA ti t hp vi nhng cng c v k thut phn t, thng qua vic phn lp nhng gen c ch t sinh vt cho ri chuyn trc tip vo sinh vt nhn, to ra nhng sinh vt bin i gen. Qu trnh ny hon ton mang tnh nhn to v khng thy trong t nhin.
3. K thut chuyn gen 3.1 Nguyn tc sinh hc ca k thut chuyn gen Khi t ra mc ch v thc hin th nghim chuyn gen cn ch mt s vn sinh hc nh hng n qu trnh chuyn gen nh sau:- Khng phi ton b t bo u th hin tnh ton nng (totipotency).- Cc cy khc nhau c phn ng khng ging nhau vi s xm nhp ca mt gen ngoi lai.- Cy bin np ch c th ti sinh t cc t bo c kh nng ti sinh v kh nng thu nhn gen bin np vo genome.- M thc vt l hn hp cc qun th t bo c kh nng khc nhau. Cn xem xt mt s vn nh: ch c mt s t t bo c kh nng bin np v ti sinh cy. cc t bo khc c hai trng hp c th xy ra: mt s t bo nu c to iu kin ph hp th tr nn c kh nng, mt s khc hon ton khng c kh nng bin np v ti sinh cy.- Thnh phn ca cc qun th t bo c xc nh bi loi, kiu gen, tng c quan, tng giai on pht trin ca m v c quan.- Thnh t bo ngn cn s xm nhp ca DNA ngoi lai. V th, cho n nay ch c th chuyn gen vo t bo c thnh cellulose thng qua Agrobacterium, virus v bn gen hoc phi ph b thnh t bo chuyn gen bng phng php xung in, siu m v vi tim.- Kh nng xm nhp n nh ca gen vo genome khng t l vi s biu hin tm thi ca gen.- Cc DNA (tr virus) khi xm nhp vo genome ca t bo vt ch cha m bo l lin kt n nh vi genome.- Cc DNA (tr virus) khng chuyn t t bo ny sang t bo kia, n ch ni m n c a vo. Trong khi , DNA ca virus khi xm nhp vo genom cy ch li khng lin kt vi genome m chuyn t t bo ny sang t bo khc ngoi tr m phn sinh.3.2 Cc bc trong k thut chuyn genQu trnh chuyn gen thc vt c thc hin qua cc bc sau:- Xc nh gen lin quan n tnh trng cn quan tm.- Phn lp gen (PCR hoc sng lc t th vin cDNA hoc t th vin genomic DNA).- Gn gen vo vector biu hin (expression vector) bin np.- Bin np vo E. coli.- Tch chit DNA plasmid.- Bin np vo m hoc t bo thc vt bng mt trong cc phng php khc nhau k trn.- Chn lc cc th bin np trn mi trng chn lc.- Ti sinh cy bin np.- Phn tch xc nhn c th chuyn gen (PCR hoc Southern blot) v nh gi mc biu hin ca chng (Northern blot, Western blot, ELISA hoc cc th nghim in vivo khc...).Nguyn liu thc hin s bin np l cc t bo thc vt ring l, cc m hoc cy hon chnh.
4. Cc phng php chuyn gen thc vt4.1 Cc phng php chuyn gen gin tip4.1.1 chuyn gen gin tip nh Agrobacterium tunefaciensNguyn l:Agrobacterium tumefaciens v A. rhizogenes l hai loi vi khun sng trong t gy ra bnh khi u hnh chp (crown gall) v bnh lng r (hairy root) cc v tr tn thng ca thc vt hai l mm. Trong A.tumefaciences c s dng ph bin cho chuyn gen vo thc vt.Agrobacterium c kh nng xm nhim t bo thc vt bng cch chuyn mt on DNA ca n vo t bo thc vt. Khi DNA vi khun c hp nht vi nhim sc th thc vt, n s tn cng vo h thng t chc ca t bo mt cch c hiu qu v s dng n m bo cho s sinh si ca qun th vi khun.S ly nhim xy ra khi t bo thc vt b tn thng. Vi khun khng xm nhp vo t bo thc vt m chuyn vo mt plasmid c hiu gy ra hnh thnh khi u v c gi l Ti plasmid. y l plasmid ln, c kch thc t 140-235 kb v c xc nh trnh t. Trong qu trnh ly nhim ca vi khun, mt phn nh ca Ti-plasmid (15-30kb) gi l T-DNA c chuyn vo v gn vi DNA ca nhn t bo thc vt (ch yu l thc vt hai l mm). Theo ccachs ny T-DNA c duy tr n nh trong b gen m n chuyn vo.Trn Ti plasmid, T-ADN c gii hn bng b phi v b tri, n mang cc gen chu trch nhim hnh thnh khi u v tng hp cc aminoaxit him nh octopin, nopalin v c gi chung l opin. Ngoi T-ADN, Ti palsmid cn c cc vng m ha cho vic ti sinh plasmid, kh nng ly nhim (cc vir gen), chuyn np v chuyn ha opin.Kch thc ca cc Ti plasmid l qu ln khi s dng lm vector, v vy cc gen hnh thnh khi u b ct b, ch cn li vng vir v T-ADN nh c im ghp gen. Cc t bo thc vt nhn nhng vector ny s khng pht trin thnh khi u v do d dng hn ti sinh thnh cy con bng k thut nui cy m t bo.
Hnh 1 To thc vt chuyn gen bng phng php chuyn gen gin tip nh AgrobacteriumCc plasmid ca Agrobacterium c s dng trong cng ngh gen thc vt gm c hai loi: vector lin hp v vector nh th. Vector lin hp: da trn s ti t hp ca hai plasmid. Mt vector lin hp gm c: v tr ghp cc gen quan tm, thng v tr ny c ngun gc t plasmid vi khun E.coli. Gen ch th khng khng sinh gip cho chn lc trong vi khun E.coli, Agrobacterium v gen chn lc hot ng c t bo thc vt. Nh vy vector lin hp c hnh thnh t: mt plasmid mang trnh t ADN mong mun v plasmid kia c cha vng vir gen v vng b lp li ca T-ADN. Sau ti t hp, mt vector lin hp c to ra v dng cho chuyn gen vo thc vt. Vector nh th: l h thng dng hai plasmid ring bit: mt cung cp T-ADN mt c tnh gy khi u, plasmid kia l Ti plasmid c kh nng thm nhp vo t bo thc vt (mang cc gen vir). Plasmid th nht mang gen chn lc thc vt v gen s c ghp vo b gen thc vt. Khi plasmid ny c a vo chng Agrobacterium c cha Ti plasmid, nhng sn phm mang gen vir c th a T-ADN vo t bo thc vt, mc d T-ADN nm trn phn t ADN khc. u im:c th p dng vi hu ht cc loi m, t bo, nhanh, n gin v mt k thut.C th x l 1 lng ln mu trong thi gian ngnBiu hin tm thi ca gen bin np c th quan st trong vng vi ngy sau bin np Nhc im: Phng php ny hiu qu cy hai l mm nhng khng hiu qu cy mt l mm.4.1.2 Chuyn gen gin tip nh virus Bn cnh vi khun Agrobacterium cn c cc h thng dng virus lm vector chuyn gen vo thc vt. V nguyn tc, bt k loi virus no cng c th c s dng lm vector chuyn vt liu di truyn vo trong t bo. Nhiu nhm trong s , cc papovavirus, adenovirus, retrovirus...c s dng vo nhng mc ch chuyn bit. s dng lm vector, cc phn khc nhau ca genome virus c thay th bng gen cu trc quan tm. Virus c th c s dng ly nhim vo t bo giai on sm ca phi trc khi c chuyn ghp vo cy m. Gen chuyn vi vector retrovirus xm nhp mt cch hiu qu vo h gen ca vt ch nhng virus s dng phi l virus an ton, khng gy bnh. u im: Chng d xm nhp v ly lan nhanh trong c th thc vt. C th mang on DNA ln hn so vi kh nng ca cc plasmid. Nhc im: Cc acid nucleic ca virus khng ghp ni vi b gen ca thc vt, bi vy AND ti t hp khng di truyn c cho cc th h sau thng qua ht. Do nhn ging cc gen phi qua con ng v tnh.S ly nhim virus thng lm yu t bo thc vt cc mc khc nhau.4.2 Cc phng php chuyn gen trc tip4.2.1 Chuyn gen bng sng bn genNguyn l ca phng php: Dng cc vin n c kch thc nh mang ADN bn vo t bo thc vt. Ngm nhng vin n nh (vi n) bng ht vng hoc tungsten c kch thc cc nh, ng knh khong 0.5 1.5 m vi dung dch c cha n DNA ngoi lai cn chuyn vo t bo thc vt. Cc vi n ny c lm kh trn mt a kim loi mng c kch thc 0.5 0.9 cm. a kim loi ny gn vo u mt vin n ln ( macroprojectile) bng nha, hoc vt liu nh. Vin n c kch thc va kht u nng sng bn gen. Khi bn, p sut hi s y vin n i vi tc cao. Ti u nng sng, vin n ln s b cn li bi mt li thp mn, cn cc vin n nh (vi n) vn tip tc di chuyn vi tc ln ti 1300 m/ giy n i tng bn ri xuyn vo t bo. Sau khi bn, tch cc m, t bo nui cy invitro ti sinh cy, t to thnh cy chuyn gen. Ch c mt t l no ca t bo mang gen chuyn do vy cn phi chn lc. Ni ta thng dng kh nn l helium p lc cao bn gen.
Hnh 2: S nguyn l hot ng ca sng bn gen u im: Thao tc d dng C th chuyn gen vo nhiu loi t bo. M, cc t bo c bin np c t l sng st cao. Cho php a cc gen vo t bo v tr mong mun. Nhc im: Nhiu bn sao ca gen bin np c th c chuyn vo t bo cng lc, kh khn trong phn tch biu hin ca gen. Hiu qu chuyn gen thp Thit b t tin.
Hnh 3: Chuyn gen thc vt nh vi khun Agrobaccterium4.2.2 Chuyn gen bng k thut xung inNguyn l ca k thut xung in: Trong cng ngh di truyn thc vt, ngi ta s dng phng php xung in chuyn gen vo protoplast thc vt. in th cao, trong thi gian ngn c th to ra cc l trn mng t bo trn (protoplast) lm cho ADN bn ngoi mi trng c th xm nhp vo bn trong t bo.
Hnh 4: S plasmid cha DNA ngoi lai i qua cc l tm thi trn mng bo cht Ngi ta chun b protoplast vi cc plasmid ti t hp mang gen mong mun cn chuyn vo thc vt.Dng thit b xung in to in th cao (200 400 V/cm) trong khong thi gian 4 5 phn nghn giy. Kt qu lm mng t bo trn xut hin cc l thng tm thi gip cho plasmid c th xm nhp v gn vo h gen thc vt. Qu trnh ny c thc hin trong cuvet chuyn dng. Sau qu trnh xung in, em protoplast nui cy trong mi trng thch hp, mi trng chn lc tch cc protoplast c bin np. Tip theo l nui cy invitro, ti sinh cy v chn lc cy chuyn gen. u im: Hiu qu chuyn gen cao, n nh, c bit l i vi cc gen n. Nhc im: T l cc t bo c chuyn gen cn thp. Sc sng ca t bo gim t ngt khi b sc in. Vic ti sinh mt s loi rt kh khn. Mc d cn hn ch nh trn nhng phng php chuyn gen bng xung in c s dng trong chuyn gen mt s loi thc vt mt l mm bao gm ng, la..
4.2.3 Chuyn gen bng vi timNguyn l c bn chuyn gen bng phng php vi tim l chuyn gen trc tip vo t bo protoplast nh thit b vi thao tc v kim vi tim.
Hnh 5: Thit b chuyn gen bng vi tim u im: Lng DNA c bin np l ty v xc nh. DNA c a vo ng v tr mong mun C th p dng i vi nhng t bo c kch thc nh b. Nhc im: Phng php ny cn thit c chnh xc cao, k thut v k nng ca ngi thc hin phi chnh xc.4.2.4 Chuyn gen nh k thut siu mK thut siu m dng chuyn gen vo t bo trn protoplast. Khi to protoplast, tin hnh trn protoplast vi plasmid ti t hp mang gen mong mun to hn hp dng huyn ph.Cm u siu m ca my pht siu m ngp trong hn hp huyn ph su khong 3mm. Cho my pht siu m vi tn s 20 KHz theo tng nhp ngn mi nhp khong 100 miligiy. S nhp khong 6-9 nhp vi tng thi gian tc ng t 600 n 900 miligiy.Sau khi siu m, em protoplast nui trong cc mi trng thch hp, chn lc tch cc protoplast c chuyn gen. Nui cy invitro ti sinh cy. Chn lc cy v a ra trng mi trng ngoi. u im: Chuyn c lng protoplast nhiu. Khng c hi i vi t bo. Nhc im: Phng tin t tin K thut cao 4.2.5 Chuyn gen bng phng php ha hcChuyn gen bng phng php ha hc l phng php chuyn gen vo t bo trn (protoplast) nh cc cht ha hc nh polyethylen glycol (PEG). Khi c mt PEG, mng ca protoplast b bin i v protoplast c th thu nhn AND ngoi lai vo bn trong t bo. u im: C th p dng i vi nhiu loi thc vt Khng i hi thit b t tin Nhc im: Tn s chuyn gen thp4.2.6 Chuyn gen trc tip qua ng phnPhng php chuyn gen qua ng phn l phng php chuyn gen khng qua nui cy invitro. Phng php ny c Ray Wu v cc cng s ti trng i hc Comell (M) xut nm 1988 trn i tng l cy la.Nguyn tc ca phng php: DNA ngoi lai c chuyn vo cy qua ng ng phn, vo bu nhy ci. Thi gian chuyn gen l lc ht phn mc qua bu nhy v lc bt u a tinh t vo th tinh. Thi im tt nht chuyn gen l lc tin hnh th tinh non, t bo hp t cha phn chia. Nh vy s chuyn gen ch din ra mt t bo sinh dc ci duy nht, khi ti sinh cy khng hnh thnh th khm.Sau thi gian hoa n 1-2 gi, ct ngang 2/3 hoc phn trn ca bng la.Sau khi ct hoa, dng ng mao qun c ng knh 0.2 nm a dung dch AND ti t hp mang gen mong mun vo bu nhy b ct. nng AND ti t hp khong 50 ug/l.Bao bng la li, ch la chn thu hi.Phn tch v xc nh kt qu chuyn gen th h sau. u im: - Khng cn qua nui cy invitro- Chuyn gen vo ng v tr mong mun Nhc im:- Mt nhiu thi gian- i hi k thut tt4.2.7 Chuyn gen trc tip vo protoplast DNA d xm nhp c vo t bo thc vt, phi loi b vch t bo to protoplast. Protoplast c th c duy tr trong mi trng nui cy nh cc t bo sinh trng mt cch c lp hoc vi mt mi trng c hiu, vch t bo c th c to thnh v ton b cc cy c th c ti sinh t cc t bo ny.Qu trnh chuyn gen nh th ny c thc hin mt cch trc tip bng mt c ch vt l n gin, khng cn c vector. nng cao hiu qu bin np, ngi ta x l protoplast vi PGE (polyethylene glycol) hoc bng xung in. u im: Phng php chuyn gen ny rt c hiu qu, c bit i vi nhng loi thc vt m phng php chuyn gen gin tip nh Agrobacterium khng th thc hin c. V d nh loi la ph Japonica, ng, la m... Nhc im: Vic to protoplast cng nh ti sinh cy t protoplast khng n gin, tn nhiu cng sc, b nh hng ca nhiu yu t mi trng.
5. Li ch, nguy c ca v hin trng s dng ca cy trng bin i gen 5.1 Nhng li ch ca cy trng bin i gen Cy trng bin i gen c nhng ng gp tch cc cho qu trnh pht trin bn vng qua cc lnh vc sau: m bo an ninh lng thc v h gi thnh lng thc trn th giiGMC c th gip n nh tnh hnh an ninh lng thc v h gi thnh lng thc trn th gii, bng cch lm tng ngun cung lng thc, ng thi lm gim chi ph sn xut, t lm gim lng nhin liu t cn s dng trong cc hot ng nng nghip, gim bt mt s tc ng bt li gn vi s bin i kh hu. Trong s 44 t USD li nhun tng thm nh cng ngh sinh hc, c 44% li nhun t vic tng nng sut cy trng, 56% li nhun t gim chi ph sn xut.Hng nghin cu mi i vi cy lng thc l pht trin kh nng chu hn; cc ging cy lng thc mi d on s c trng Hoa K nm 2012, tiu vng Sahara thuc chu Phi nm 2017. Bo tn a dng sinh hcGMC c li tim tng i vi mi trng. GMC gip bo tn cc ngun li t nhin, sinh cnh v ng, thc vt bn a. Thm vo , GMC gp phn gim xi mn t, ci thin cht lng nc, ci thin rng v ni c tr ca ng vt hoang dVic ng dng cng ngh sinh hc trong nng nghip l gii php gip bo tn t trng, cho php tng sn lng thu hoch cy trng trn 1,5 t ha t trng hin c, xo b tnh trng ph rng lm nng nghip, bo tn a dng sinh hc ti cc cnh rng v khu bo tn trn khp th gii. Theo c tnh, hng nm cc nc ang pht trin mt khong 13 triu ha rng v cc hot ng nng nghip. T nm 1996 n 2007, GMC bo v 43 triu ha t trn th gii, c tim nng rt ln trong tng lai. Gp phn xo i gim ngho50% nhng ngi ngho nht trn th gii l ngi nng dn cc nc ang pht trin, ngho ti nguyn, 20% cn li l nhng ngi nng dn khng c t trng, ph thuc hon ton vo ngh nng.V th, tng thu nhp cho ngi nng dn ngho s ng gp trc tip vo qu trnh xo i gim ngho trn th gii, tc ng trc tip n 70% ngi ngho trn ton th gii.Tnh n thi im hin ti, cc ging bng v ng bin i gen mang li li nhun cho hn 12 triu nng dn ngho cc nc n , Trung Quc, Nam Phi, Philippin v s ngi hng li s cao hn trong thp nin th hai ny. Trong vic tp trung pht trin cc ging go bin i gen c th mang li li nhun cho khong 250 triu h nng dn ngho canh tc la chu . Gim tc hi ca cc hot ng nng nghip i vi mi trngHot ng nng nghip truyn thng ca con ngi c tc ng rt ln vi mi trng. S dng cng ngh sinh hc, c th gim ng k cc tc hi . Trong thp nin u tin ng dng cng ngh sinh hc, cng ngh tin tin ny gip gim lng ln thuc tr su, gim lng xng du cn s dng trong cc hot ng nng nghip, gim lng kh CO2 thi ra mi trng do cy xi t, bo tn t v m nh phng php canh tc khng cn cy xi, gip t trng hp thu c mt lng ln kh CO2 t khng kh. Tng lng thuc tr su ct gim trong khong thi gian t 1996 n 2007 c tnh t 359 ngn tn thnh phn kch hot (a.i.), tng ng vi 9% lng thuc tr su cn s dng, lm gim 17,2% cc tc hi i vi mi trng, tnh theo ch s tc hi mi trng (EIQ). Trong nm 2007, cng ngh sinh hc lm gim 77.000 tn thuc tr su s dng trong nng nghip (tng ng vi 18% lng thuc tr su s dng), ch s EIQ gim 29% (Brooks v Barfoot, 2009). Gim thiu tc hi ca bin i kh hu v gim lng kh gy hiu ng nh knh (GHG)GMC c th gip gii quyt nhng lo ngi ln nht v mi trng: gim thiu cc loi kh gy hiu ng nh knh, gim thiu tc ng ca thay i thi tit. Th nht, gim lng kh CO2, lm gim lng nhin liu ho thch, gim lng thuc tr su v thuc dit c. Theo nh gi, GMC lm gim khong 1,1 t kg kh CO2 thi ra t cc hot ng nng nghip, tng ng vi ct gim 500 ngn xe t lu thng trn ng. Th hai, phng php canh tc khng cn cy xi nh cng ngh sinh hc lm gim thm 13,1 t kg kh CO2, tng ng vi gim 5,8 triu xe t lu hnh trn ng. Nh vy, trong nm 2007, tng lng kh CO2 m cng ngh sinh hc lm gim trn ton th gii t mc 14,2 t kg, tng ng vi loi b 6,3 triu xe t (Brooks v Barfoot, 2009). Tng hiu qu sn xut nhin liu sinh hcCng ngh sinh hc c th gip ti u ho chi ph sn xut nhin liu sinh hc th h th nht v th hai, nh to ra cc ging cy chu tc ng ca mi trng (kh hn, nhim mn, nhit khc nghit) hoc cc tc ng ca sinh vt (su bnh, c di), nng cao nng sut thu hoch ca cy trng, bng vic thay i c ch trao i cht ca cy. S dng cng ngh sinh hc, cc nh khoa hc cng c th to ra nhng enzym y nhanh qu trnh chuyn ho ca nguyn liu sn xut thnh nhin liu sinh hc. Gp phn n nh cc li ch kinh tKho st gn y nht v tc ng ca GMC trn ton cu t nm 1996 n 2007 (Brooks v Barfoot, 2009) cho thy li nhun m GMC mang li cho ring nhng ngi nng dn trng chng trong nm 2007 t 10 t USD (6 t USD cc nc ang pht trin, 4 t USD cc nc cng nghip). Tng li nhun trong giai on 1996 - 2007 t 44 t USD, t cc nc ang pht trin v nc cng nghip.5.2 Nhng tc hi tim tng ca cy trng bin i genNhng mi tc hi tim tng ca cy trng bin i gen th hin nhng kha cnh sau: i vi sc khe con ngiBn cnh nhng li ch c bn ca GMO, theo nhiu nh khoa hc th gii, th loi thc phm ny cng tim n nhiu nguy c nh hng lu di ti sc khe cng ng, nh kh nng gy d ng, lm nhn khng sinh, c th to ra c t v gy c lu di cho c th, v.v...y l mt trong nhng tranh lun ch yu v vn ch c tho g khi chng t c rng sn phm protein c c t s chuyn i gen khng phi l cht gy d ng. Gen khng sinh c th c chuyn vo cc c th vi sinh vt trong rut ca ngi v ng vt n thnh phm bin i gen. iu ny c th dn ti vic to ra cc vi sinh vt gy bnh c kh nng khng thuc. Vic chuyn i gen t thc phm bin i gen vo t bo c th con ngi hay vo vi trng trong ng rut c th ngi l mi quan tm thc s, nu nh s chuyn i ny tc ng xu ti sc khe con ngi. i vi a dng sinh hcNguy c GMC c th pht tn nhng gen bin i sang h hng hoang d ca chng, sang su bnh c nguy c lm tng tnh khng ca chng i vi c tnh chng chu su bnh, thuc dit c hoc lm tng kh nng gy c ca GMC i vi nhng loi sinh vt c ch.Di sc p ca chn lc t nhin, cn trng s tr ln khng cc loi thuc dit cn trng do cy trng to ra v gy thit hi cho cy trng. Gii php GMC khng bn vng cho mt s vn nh khng su bnh, v cc loi dch hi ny c th ti xut hin do bn cht di truyn thch ng vi mi trng ca chng.Cy trng khng su c kh nng tiu dit cc loi cn trng hu ch khc nh ong, bm, v.v... lm nh hng n chui thc n t nhin, nh hng n a dng sinh hc ni chung. Vic trng GMC i tr, tng t nh vic ph bin rng ri mt s ging nng sut cao trn din tch rng ln, s lm mt i bn cht a dng sinh hc ca vng sinh thi, nh hng n chu trnh nit v h sinh thi ca vi sinh vt t. i vi mi trngNguy c u tin l vic GMC mang cc yu t chn lc (chu lnh, hn, mn hay khng su bnh) pht trin trn lan trong qun th thc vt. iu ny lm mt cn bng h sinh thi v lm gim tnh a dng sinh hc ca loi cy c chuyn gen.Nguy c th hai l vic GMC mang cc gen khng thuc dit c c th th phn vi cc cy di cng loi hay c h hng gn gi, lm ly lan gen khng thuc dit c trong qun th thc vt. Vic gieo trng GMC khng su bnh trn din rng, v d, khng su c thn, c th lm pht sinh cc loi su c thn mi khng cc loi GMC ny. Vic s dng thuc tr su sinh hc Bt cho php phng tr hiu qu su bnh, nhng sau 30 nm s dng, mt s loi su bnh tr nn nhn thuc mt vi ni.Nguy c cui cng l vic chuyn gen t cy trng vo cc vi khun trong t. Tuy nhin, kh nng xy ra iu ny l v cng nh.Hin nay, cc chuyn gia cng ngh sinh hc ang c gng gim thiu cc ri ro nu trn v theo di cn thn cc th nghim GMC trong phng th nghim, cng nh ngoi ng rung trc khi a ra th trng thng mi.Ni tm li, nu c thit k v s dng ng phng php, th c th qun l c cc nguy c ca GMC i vi mi trng mt cch hiu qu.5.3 Hin trng v xu hng pht trin cy trng bin i gen trn th gii Cng ngh sinh hc c nhng bc tin nhy vt gp phn mang li nhng thnh tu to ln cho loi ngi. Trong 13 nm, t 1996 n 2008, s nc trng GMC ln ti con s 25 - mt mc lch s - mt ln sng mi v vic a GMC vo canh tc, gp phn vo s tng trng rng khp ton cu v gia tng ng k tng din tch trng GMC trn ton th gii ln 73,5 ln (t 1,7 triu ha nm 1996 ln 125 triu ha nm 2008). Trong nm 2008, tng din tch t trng GMC trn ton th gii t trc ti nay t 800 triu ha. Nm 2008, s nc ang pht trin canh tc GMC vt s nc pht trin trng loi cy ny (15 nc ang pht trin so vi 10 nc cng nghip), d on xu hng ny s tip tc gia tng trong thi gian ti nng tng s nc trng GMC ln 40 vo nm 2015.
Hnh 6: Din tch cy trng cng ngh sinh hc trn ton cu6. Cc hng chnh trong thc vt chuyn gen6.1 chuyn gen khng su bnh
Trong 30 nm gn y, trong sn xut nng nghip, ngi ta s dng thuc tr su vi sinh Bt do vi khun Bacillus thuringiensis to ra. Vi khun ny sn xut ra cc protein kt tinh rt c i vi u trng ca cn trng nhng khng gy c i vi ng vt c xng sng. Vi khun ny sn sinh 3 ngoi c t toxin v 1 ni c t toxin (endotoxin). Ni c t toxin c vai tr quan trng nht. Tinh th protein c t ca vi khun ny khi vo mt cn trng s b cc enzyme protease phn gii thnh cc on peptit, trong c on c khi lng khong 68000 dalton cha khong 1200 axit amin lm hng rut cn trng.
Nm 1987, cc nh nghin cu B tch c gen m ha cho protein c t (Bt toxin) ny. Cc gen m ha c t ny nm trn plasmid ca vi khun, c gi chung l Cry (crystal) (theo Held v cs). Ngi ta phn nhm gen endotoxin thnh 6 nhm chnh k hiu t CryI n CryVI .+ CryI dit u trng b cnh vy (Lepidoptera)+ CryII dit u trng b cnh vy (Lepidoptera ) v b hai cnh (Diptera)+ CryIII dit u trng b cnh cng (coleoptera)+ CryIV dit u trng b hai cnh (Diptera)+ CryV dit u trng b cnh vy (Lepidoptera ) v b hai cnh (Diptera)+ CryVI dit tuyn trng Cc gen ny c tch ra, xc nh trnh t, tin hnh tng hp v thit k vo cc vector chuyn gen, sau chuyn vo cc cy trng nh bng, ng, u tng, lakt qu to ra hng lot cy trng khng su. tng hiu qu khng su ngi ta ct bt cc on gen khng cn thit thay th vng khi ng, ch huy lm tng hot tnh ln nhiu ln.6.2 Chuyn gen khng thuc dit c Trong nn sn xut nng nghip hin i quy m sn xut ln cn phi s dng thuc dit c di. Vn t ra l khi phun thuc dit c th ch dit c m khng gy hi n cy trng, c bit l la. Mun vy ngi ta phi to ra cy trng khng thuc dit c. Cch lm hiu qu nht l chuyn gen khng thuc dit c vo cy trng. Cn phi tm gen c tc dng khng thuc dit c nh cc gen to ra enzyme lm mt hot tnh ca thuc dit c hoc cc enzyme tng cng cho cc enzyme d b phn hy bi thuc dit c. C nhiu thuc dit c khc nhau c s dng trong ph bin nht l thuc dit c glyphosat, c tc dng dit c tt, d t phn hy v t gy nhim mi trng. C ch dit c l thuc km hm s hot ng ca mt enzyme c tn l enzyme Enol pyruvat sikimat phosphat synthetase (EPSPS ). Enzyme EPSPS c chc nng chuyn ha sn phm quang hp thnh axit mang mch vng c tn l axit sikimic. Axit sikimic khng c hnh thnh s lm ri lon ton b qu trnh trao i cht ca c v lm cho c cht.Ngi ta tm gen m ha EPSPS t vi sinh vt v t nhng cy chu c thuc dit c glyphosat, tin hnh tch gen ra ri ci bin gen ny sau chuyn chng vo cy trng. Kt qu to ra cy trng c hm lng v hot tnh ca enzym EPSPS cao gp 4 ln so vi cy trng bnh thng v cy hon ton chng chu c vi thuc dit c glyphosat.Nh phng php ny, ngi ta to ra nhiu loi cy trng khng thuc tr c nh u tng, ng, bng..6.3 Chuyn gen to cy khng virus gy bnh Virus thc vt gy hi nghim trng cho cy trng v l loi bnh khng th dng cc loi thuc thng thng phng tr c. Do vy vic to cy khng virus l rt quan trng. C nhiu cch to cy khng virus, chuyn gen m ha protein v ca virus, chuyn gen to enzyme phn gii virus (nh enzyme ribozyme) hoc chuyn gen c trnh t i bn (antisens) vi ARN ca virus. Cc i bn ny s kha li s sao chp v s phin m ca ARN virus. K thut chuyn gen m ha v protein ca virus thng c dng ph bin.
Virus c cu to gm 2 phn: phn li l axit nucleic (ADN hoc ARN) v phn v protein. Khi c mt gen m ha protein v ca virus trong t bo ca cy th s gy hiu ng km hm s tng hp protein v ca gen to v virus. Do vy virus khng nhn ln c. Nhiu loi cy trng chuyn gen to v ca nhiu loi virus nn khng c cc virus gy bnh nh: u khng vi virus gy bnh m vng (PRVS-papaya ringspots virus), cy thuc l khng vi virus khm da chut (CMV- cucumber mosaic virus), cy thuc l khng vi virus khm afla (AMV-afla mosaic virus), khoai ty khng vi virus X, virus Y( PVX & PVY- potato virus hoc ), khoai ty khng vi virus xon l ( PLRV- potato leafroll virus ), cy cam, qut khng bnh virus gy tn li tristeza (CTV- citrus tristeza virus)6.4 chuyn gen to cy sn xut protein ng vt c nghin cu to ra loi u tng v ng c hm lng cc loi amino acid khng thay th cao hn. Ngoi ra, cc nghin cu khc cng ang c tin hnh nhm lm tng hm lng phosphore trong thc n chn nui. Sn xut protein ng vt bng phng php nui cy m, t bo ng vt rt tn km, d b ly nhim. V vy, cc nh khoa hc tm cch gii trnh t ca cc gen m ha cho protein ng vt , thit k li v chuyn vo thc vt, bin thc vt thnh c th sn xut protein ng vt V d: gen tng hp lactoferin l 1 protein c trong sa ngi, c chuyn vo khoai ty, la v thu c cy khoai ty, cy la c kh nng tng hp lactoferin. Khoai ty l thc n hng ngy ca nhiu nc. Tuy nhin, hm lng lactoferin c tng hp trong khoai ty thp. Nu chuyn gen lactoferin vo la th gen ny biu hin tt hn, kh nng tng hp lactoferin vi hm lng cao. V d, to c ging la c th t hm lng ti 5g lactoferin trong 1kg go v kh n nh qua cc th h. Mt hng quan trng khc l sn xut thc phm chc nng. iu c ngha l cn chuyn nhiu gen tng hp ra cc protein c tc dng nh l cc khng nguyn vo cc i tng cy trng nh rau, u, cy n qu. Do vy cc cy ny to ra cc vacxin.
6.5 chuyn gen lm thay i hm lng v cht dinh dng ca cyu tng v ng l thc n cho ngi v gia sc. Tuy nhin, trong u tng v ng c cc protein cha t axit amin methionine. Ngi ta nghin cu chuyn gen m ha cho protein cha nhiu methionin vo u tng v ng. Kt qu l cc cy chuyn gen tng loi protein giu methionin ln hn 8% trong tng s protein c trong ht.Thaumatin l nhng protein c chit xut t tht qu ca cy Thaumatococus danielle, c ngt gp 1.000 ln ng saccharose. Ngi ta thnh cng trong vic chuyn mt gen m ha cho thaumatin (thaumatin II) vo cy khoai ty, to mt cy khoai ty c l, thn r, c u ngt. Kt qu ny m ra mt trin vng rt ln i vi cy n qu ngt.6.6 chuyn gen to ging hoa c mu sc miMu sc ca hoa, c bit l hoa c mu xanh, nhung en rt c gi tr. Trong m ca cnh hoa nht l cc biu b thng cha cc sc t to mu sc hoa. C 3 nhm antocyanin c bn c pht hin l dn xut ca cc cht pelargonidin, cyanidin v delphinidin. Cc sc t l dn xut ca pelargonidin thng c mu da cam, hng v . Cc sc t l dn xut ca cyanidin c mu hoc mu hoa c. Cc sc t l dn xut ca delphinidin c mu ta, mu xanh v mu xanh en.S phi hp ca 3 nhm antocyanin ny to ra ph sc hoa rt rng, trn c s bit cc gen m ha cho cc enzym tham gia vo bin i sc t, ngi ta chuyn gen m ha hoc gen c ch hot ng ca cc enzyme nhm iu khin hng chuyn ha sc t, t to ra hoa c mu sc khc nhau. Nhiu mu sc mi ca hoa c to ra nh tch chit cc gen chu trch nhim tng hp sc t t cc sinh vt khc nhau v chuyn vo cc ging hoa, to ra nhiu ging cho mu hoa mi l.
7. Mt s ng dng ca thc vt chuyn gen trong cng ngh thc phm 7.1 Cy ngMc ch bin i gen: to ng bin i gen mang cc tnh trng nh khng cn trng v chng chu thuc dit c. Dung phi ng trong nui cy dich huyn phu phat sinh phi tai sinh cac cy hu thu mang gen bar bin nap. S dung phng phap bn gen va chon loc bng thuc dit co bialaphos a cho kt qua la m callus phat sinh cac phi c bin nap gen. Cac cy bin nap gen hu thu a c tai sinh, n inh di truyn va biu hin gen bar cung vi hoat tinh chc nng cua enzyme phosphinothricin acetyltransferase quan sat c trong nhng th h sau. Gn y, cac kt qua bin nap gen gian tip ng nh Agrobacterium cung a c thng bao. Cac th bin nap gen cua dong ng lai gn (inbredline) A188 a c tai sinh sau khi ng nui cy (cocultivation) gia binary vector vi phi non. Tn s bin np c thng bao dong A188 la khoang 5-30%. Cac th lai th h th nht gia dong A188 va 5 dong lai gn khac c bin nap vi tn s khoang 0,4-5,3% (tinh theo s cy bin nap gen c lp/phi). Ng- Bt to ra cht khng cn trng t vi khun Bacillus thurigenis gip khng su bnh v thuc tr su bin i gen cho nng sut cao hn ng bnh thng.
Hnh 7:So snh ng khng bin i gen (tri) v ng Bt (phi) C rt nhiu sn phm lm t ng bin i gen nh: Khoai ty chin Tortilla, syrup ng c hm lng fructose cao c s dng nh 1 cht ngt trong sn xut bnh nng.7.2 Cy u nnh
Hnh 8: u nnh bin i genMc ch bin i gen: u tng c bin i gen mang cc tnh trng nh kh nng chng chu thuc dit c v c hm lng oleic acid cao. u tng l loi cy cha du em li li ch kinh t to ln nht trn th gii. Ht u tng c cha t l amino acid khng thay th nhiu hn c tht, do vy u tng l mt trong nhng loi cy trng lng thc quan trng nht trn th gii hin nay.
Theo GMO compass, hn mt na s cy trng u tng trn th gii nm 2007 (58,6%) c bin i gen vi t l cao hn bt k cc cy trng khc.Nhng c gng u tin cy u tng bin nap gen tp trung vic tai sinh cy t protoplast, nui cy dich huyn phu, phat sinh phi va ti u hoa bng ky thut bn gen (vi n).u nnh bin i gen c s dng lm thc n cho gia sc, gia cm. Ngoi ra, cn c s dng sn xut nhiu loi ph gia thc phm (v d nh: Lecithin t u tng bin i gen).7.3. BngCy bng l loi cy cung cp si ch yu, chim ti mt na s lng vi si trn th gii. Ngoi ra, mt lng nh ht bng c dng nh mt ngun thc phm, thc n gia sc v du n cho con ngi v vt nui. Du ht bng c tinh ch trc khi dng loi b cht gossypol c hi cho ngi v tiu ha ca ng vt. Phng thc bin nap gian tip thng qua Agrobacterium tumefaciens la ky thut u tin c s dung bin nap gen vao cy bng ging Coker 312. Cy bng bin nap gen cung cua ging trn a c thu hi sau khi bn gen vao dich huyn phu nui cy phat sinh phi. Hu ht cac ging bng co gia tri kinh t khac khng th tai sinh cy t giai oan callus. Mt s it cac ging o co th tai sinh cy nhng qua trinh nay thin v bin di dong v tinh (somaclonal variation). Phng thc phn phi gen ngoai lai trc tip vao trong m phn sinh cua tru phi da trn cng ngh ACCELL cung c phat trin va ngi ta a thu hi thnh cng cy bin nap gen.Mc ch bin i gen: khng su bnh bng cch sn xut c t Bt; khng thuc dit c c thnh phn glyposate; gip cy bng thch ng vi kh hu a phng.Bng bin i gen c ch yu sn xut du bng. Du t bng bin i gen dng chin v nu n nh du bnh thng.
Hnh 9: Du t bng bin i gen7.4. u u l mt loi cy trng quan trng khu vc ng Nam , c dng lm thc n ph bin trong cc h nng dn sn xut nh v gia nh ca h.Cy u Hawaii (M) c cc nh khoa hc thuc hai trng i hc danh ting (Hawaii v Cornell) nghin cu thnh cng ging cy ny. u bin i gen Hawaii gip khi phc ngnh trng u Hawaii (M) sau trn i chin vi dch bnh m vng vo thp nin cui th k 20.Hin nay, ging u chuyn gen khng virus (bnh m vng u ) c pht trin cc nc thuc khu vc ng Nam . Mc ch bin i gen: khng virus (PRSV) nhng khng lm thay i c tnh ca u lm tng nng sut v h gi thnh.
Hnh 10: u bin i gen Hawaii7.5 Cy la Mc ch bin i gen: Chuyn gen cy la ang c tp trung vo tnh trng chng chu thuc dit c v sn xut vitamin A (ging la vng). Kt qua tai sinh cua cy lua bin nap gen bng xung in hoc PEG thng qua nui cy protoplast c thng bao ln u tin cach y khong 10 nm. Cac nghin cu sau o cung a s dung hai ky thut nay bin nap gen vao protoplast va phuc hi cac cy bin nap gen hu thu.Hin nay hn 40 ging a c bin nap gen thanh cng Cy la ch sn sinh ra hp cht caroteoid c chuyn thnh vitamin A trong nhng b phn c mu xanh ca cy, tuy nhin trong ht go m con ngi vn dng li khng c hp cht ny. Chnh v th s thiu ht vitamin A thng xy ra nhng ni s dng go lm lng thc chnh. Go vng TM l mt loi ng cc chuyn gen c kh nng nng cao hm lng vitamin A trong ba n hng ngy. Loi go ny c kh nng sn sinh v lu gi cht -carotene. N c t tn l go vng TM bi v ni nh (cht bt bn trong ca ht go) ca n c mu vng nht, do cht -carotene to ra.Nh vy, go vng gip gii quyt vn lng thc, thiu vitamin A cc nc km pht trin.
Hnh 11: Go bin i gen 7.6 Cy ci duMc ch bin i gen: Cy ci du c bin i gen vi mc ch ci thin cht lng dinh dng, c bit l hm lng cht bo ha tan ca loi cy ny. Cy ci du c trng ch yu cc vng pha ty Canada v mt t Ontario v ty bc Thi Bnh Dng, trung tm pha bc v vng ng nam nc M. Ngoi ra, cy ci du cng c trng cc nc khc ca chu u v Australia. Hin nay, n c trng gn nh ton b t nc.
Hnh 12: Cy ci du bin i genCy ci du bin i gen c dng sn xut du Canola (Canadian oil low acid). y l mt pht minh ca ngi Canada v c chnh ph tr cp.Cc con ong ht mt hoa t cy ci du bin i gen sn xut mt ong. Tin s Martina t Trung tm nghin cu sinh hc lin bang Nng nghip v Lm nghip (BBA) pht hin ra rng nhng con ong khng phn bit gia phn hoa t cy trng bin i gen v thng thng
Hnh 13: Du Canola
7.7 Khoai ty Mc ch bin i gen: Khoai ty c bin i gen mang cc tnh trng nh kh nng khng cn trng v khng virus.
Hnh 14: Khoai ty bin i genKhoai ty c xem l cy lng thc quan trng th t trn th gii, vi sn lng hng nm ln n 300 triu tn v c trng trn hn 18 triu hecta. Hin nay, hn mt phn ba sn lng khoai ty trn th gii l ca cc nc ang pht trin. Sau khi Lin X tan r th Trung Quc tr thnh nc sn xut khoai ty ln nht th gii. n ng th t. Mc d sn lng khoai ty ti chu u gim xung t u nhng nm 1960, nhng b vo sn lng khoai ty chu v nam M li tng ln v th sn lng khoai ty trn th gii vn cng ngy cng tng. Mc tiu cho tng li: Khoai ty bin i gen khng bnh bc l ang c th nghim.
Hnh 15: Khoai ty b bnh bch l
7.8 C chua C chua c coi l loi qu vn ph bin nht hin nay. C chua thng rt d trng v mt s ging cho nhng v ma bi thu. Cht lng qu c chua chn cy vt xa tt c nhng loi qu khc c mt trn th trng thm ch trong c ma v. Cy c chua rt mm v thch hp vi thi tit m p th nn n thng c trng vo v h. Mc ch bin i gen: C chua c bin i gen mang cc tnh trng nh kh nng chu thuc dit c, khng vt k sinh v lm chm qu trnh chn ca qu.
Hnh 16:C chua bin i gen (phi)Cc nh khoa hc Anh va to ra ging c chua mu tm cha nhiu cht chng oxy ha c th gip ngn chn bnh ung th. to ra ging c chua tm, cc nh khoa hc a mt s gen ca cy hoa mm ch (snapdragon) vo c chua thng thng, sau th nghim loi c chua mi ny trn chut mang bnh ung th. H pht hin tui th chut c ko di hn khi n bt c chua tm.Nghin cu do cc nh khoa hc Anh, c, v H Lan thc hin v c cng b trn tp ch Nature Biotechnology. Phc v cuc th nghim c ba nhm chut t bin gen mang bnh ung th. Nhng con chut ny u mang u bu v s cht sm.Nhm th nht c cho n thc n tiu chun, nhm th hai n bt lm t c chua bnh thng c ng lnh v nhm th ba n bt lm t c chua tm m sy kh ng lnh.Kt qu nhm chut n c chua tm sng c trung bnh 182 ngy so vi 142 ngy ca nhm chut n thc n bnh thng v 146 ngy ca nhm n c chua . Thi gian sng di nht ca chut n thc n bnh thng l 211 ngy v ca chut n c chua tm l 260 ngy.Cc nh khoa hc cho bit ging c chua mi c lng anthocyanin, cht to mu cy ci, cao hn. Chng thng c trong nho, cy mm xi, vit qut v cc loi tri cy khc. Cc nh nghin cu a ra gi thit anthocyanin c cng dng chng oxy ha v c nhiu li ch v sc khe, t phng chng bnh tim n bnh ung th.
Hnh 17: C chua bin i gen c mu tm7.9 Sn phm t saSn phn t sa b bin i gen tuy khng phi l thc phm c ngun gc t thc vt bin i gen nhng nhm cng xin ni thm
Hnh 18: Mc ch bin i gen: tng sn lng sa 22% n b ca M c tim ti t hp (gen bin i) hoc mn tng trng ca loi b (rbGH). Sn lng sa thu c tng 15%.7.10 u H Lanu l mt cy trng quan trng lun canh, cy trng ny c th b tn ph bi mt u ph hoi (Bruchus pisorum).Vin nghin cu t nhn c CSIRO (Csiro Plant Industry) lm vic gn 10 nm nghin cu u H Lan khng mt. i vi nc c, mt u l mt th thch ln. Mt u l mt loi cn trng gy hi trng trong ht u. Nu khng s dng thuc tr su 30% ht cy c th b ph hy.Cc nh khoa hc sn xut mt loi protein l cht c ch amylase nhm ngn nga s phn hy ca tinh bt trong h thng tiu ha ca mt u lm cho chng cht i trc khi kp gy ra thit hai.Tuy nhin, vic pht trin u H Lan bin i gen b gin on vo nm 2005, v cho thy nhng phn ng tiu cc chut i vi u H Lan. (Prescott et al 2005).
Hnh 19: u H Lan bin i genth hin mt gen c ch amylase c kh nng khng su c ht u (tri).u H Lan thng thng (phi)Nm 2013, cc nh nghin cu ti i hc Y khoa Vienna tin hnh th nghim cho chut n u H Lan khng mt bin i gien (GM) nghin cu tnh d ng ca loi u ny.Nhm nghin cu t i hc Y Vienna nghin cu phn ng min dch chut n cc loi u khc nhau, u H Lan khng bin i gien v u H Lan bin i gien i din cho u bin i gien ca cht c ch -amylase. Nhng con chut cho thy mc phn ng min dch tng t vi bt k loi thc phm no m chng tiu th.Tin s Michelle Epstein - nh nghin cu chnh cho bit: Chng ti quan st thy rng phn ng min dch chut l nh nhau bt chp liu c cht c ch t u hay khng, hoc t u H Lan bin i gen biu hin cht c ch v thm ch c nhng loi u H Lan khng bin i gien. Nhng kt qu ny chng minh rng u H Lan bin i gien AI l khng gy d ng cho chut nhiu hn so vi u H Lan khng bin i gien.8. Kt lun Cy trng bin i gen vi nhng tnh trng vt tri c sn xut ngy cng nhiu, em li nhiu li ch, c nhiu ng dng, c bit trong lnh vc thc phm ngnh m ngun nguyn liu chim a s l t thc vt. Tuy nhin vic s dng cy trng bin i gen cn gy nhiu tranh ci. V vy, chng ta cn cn nhc vic s dng mt cch hiu qu.
TI LIU KHAM KHO
[1] Cng ngh sinh hc tp 2 (cng ngh sinh hc t bo)- V Vn V, Nguyn Mng Hng, L Hng ip[2] Cng ngh sinh hc tp 4 (cng ngh di truyn)- TS. Trnh nh t[3] Cng ngh chuyn gen ng, thc vt- Trn Quc Dung (ch bin), Nguyn Hong Lc, Trn Th L[4] http://vietsciences.free.fr/thuctap_khoahoc/thanhtuukhoahoc/thucphamchuyengen.htm [5] http://myweb.tiscali.co.uk/hbtdp/_private/Sinh%20vat%20bien%20doi%20gen%20-%20Part%207%20-%20TDH.htm[6] http://donabio.com.vn/CNSH/tabid/86/isd_news_news/218/Default.aspx[7] http://doc.edu.vn/tai-lieu/tieu-luan-thuc-pham-bien-doi-gene-52764/[8] http://www.agroviet.gov.vn/Pages/news_detail.aspx?NewsId=27429
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