第八章-生物技术保鲜-保藏学第二部分-保藏原理部分课件.ppt

《第八章-生物技术保鲜-保藏学第二部分-保藏原理部分课件.ppt》由会员分享，可在线阅读，更多相关《第八章-生物技术保鲜-保藏学第二部分-保藏原理部分课件.ppt（41页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、第八章第八章生物技术保鲜生物技术保鲜植物采后腐败植物采后腐败 n nNumberofefficientchemicalandphysicalNumberofefficientchemicalandphysicaltreatmentscanbeusedtopreservefreshfoodstreatmentscanbeusedtopreservefreshfoodsn nIdealwaytopreservefoods(plant)Idealwaytopreservefoods(plant)GeneticallyprogrammetofoodstodothejobGeneticallyprogr

2、ammetofoodstodothejobbythemselveswithanyhumaninterventionbythemselveswithanyhumaninterventionn nOnceplanttissuesareharvested,theyOnceplanttissuesareharvested,theyengageinanacceleratedsenescenceengageinanacceleratedsenescenceprocessthatleadstospoilageprocessthatleadstospoilagen nPlantorgansenescenceP

3、lantorgansenescence NaturalprocessNaturalprocess ControlledbygeneControlledbygenen nHarvestingdetachingorgansfrommainHarvestingdetachingorgansfrommainplantsplantsn nAddingastrongstresscomponentspeedingAddingastrongstresscomponentspeedingupthedecayupthedecayn nGeneticengineeringhasthepotentialtoslowd

4、ownthenaturalsenescenceprocessesandalleviatethestressresponsesfromharvestedtissues水果的分类水果的分类n nTowmajorclassesofunprocessedplantfoodstuffsn nClimactericn nNon-climacteric n nBasedonBasedon WhetherornotexhibitarespiratoryriseattheWhetherornotexhibitarespiratoryriseattheonsetofsenescenceaccompaniedbya

5、nauto-onsetofsenescenceaccompaniedbyanauto-catalyticproductionofethylenecatalyticproductionofethyleneTheclimactericpatternofrespirationinclimactericfruits跃变型果实跃变型果实n nEthyleneplayimportantroleinripeningEthyleneplayimportantroleinripeningn nOnripening,largeincreaseinethyleneOnripening,largeincreasein

6、ethyleneproductionandsensitivetoethyleneproductionandsensitivetoethylenen nExposuretoethyleneaccelerateripeningExposuretoethyleneaccelerateripeningn nPracticalproblemsduringtransportandPracticalproblemsduringtransportandstoragestoragePresenceofotherripeningfruitswillactinPresenceofotherripeningfruit

7、swillactinasynergisticwaytoacceleratesenescenceasynergisticwaytoacceleratesenescenceSome Climacteric&Non-climacteric fruits&vegetablesClimactericClimactericNon-climactericNon-climactericAppleAppleNectarineNectarineGrapeGrapeApricotApricotPapayaPapayaPineapplePineappleBananaBananaPeachPeachOrangeOran

8、geMangoMangoPearPearStrawberryStrawberryVegetableVegetableTomatoTomatoCucumberCucumberFruit成熟中的变化成熟中的变化n nClimactericClimacteric ChemicalchangesChemicalchangesn nSugar,nutritionalcompounds,color,tasteSugar,nutritionalcompounds,color,tasten nNarrowtimeNarrowtime StructureStructuren nNon-climactericNo

9、n-climacteric EffectofethyleneislittleEffectofethyleneislittle MostprocessisidenticalMostprocessisidentical乙烯生物合成途径乙烯生物合成途径 Methionine(Met)SAMACCEthylene(C2H4)ACC synthase(ACS)ACC oxidase(ACO)AdoMet synthetaseSAM,S-adenosyl methionine;ACC,1-aminocyclopropane-1-carboxylic acidTransgenic tomatoesNon-r

10、ipening Ripening (2)Manipulating ACO n nACOACO FinalenzymeonthebiosyntheticpathwayFinalenzymeonthebiosyntheticpathwayn nAntisensegeneofACOintomatoAntisensegeneofACOintomato ReducedlevelsofethyleneReducedlevelsofethylene ExtendedripeningperiodExtendedripeningperiodn nRipeningwasdelayedbythesuppressio

11、nofRipeningwasdelayedbythesuppressionoftheACCoxidasegenetheACCoxidasegene(3)Depletion of SAM and ACC n nBacterialgenecodingACCdeaminaseBacterialgenecodingACCdeaminase(脱氨基酶脱氨基酶)tomatotomato EthylenereducedEthylenereduced FirmnessincreasedFirmnessincreasedn nAgeneencodingSAMhydrolaseAgeneencodingSAMhy

12、drolasetomatotomato EthylenereducedEthylenereduced FruitstayedfirmerFruitstayedfirmer(4)Inhibition of ethylene receptor n nEthyleneisperceivedbythecellbyafamilyEthyleneisperceivedbythecellbyafamilyofreceptorsofreceptorsn nSuccessSuccess SuppresstheexpressionofNr(CSuppresstheexpressionofNr(C2 2H H4 4

13、receptor)receptor)FruitswithverylowlevelsoftheNrgeneFruitswithverylowlevelsoftheNrgeneexpressionshoweddelayedripening.expressionshoweddelayedripening.Non-climacteric fruits n nLittleisknownaboutthemechanismsLittleisknownaboutthemechanismscontrollingfruitripeningcontrollingfruitripeningn nEconomicimp

14、ortanceEconomicimportancen nImportantagronomictrait:firmnessImportantagronomictrait:firmnessn nRipeningusuallyaccompaniedbyincreaseofRipeningusuallyaccompaniedbyincreaseofsofteningsoftening ManipulationoffruitfirmnesscanleadtolongerManipulationoffruitfirmnesscanleadtolongereffectiveperiodofconsumera

15、cceptabilityandeffectiveperiodofconsumeracceptabilityandreducedlossesreducedlossesManipulation of fruit firmness -the case of strawberryn nTransgenicstrawberryplantsTransgenicstrawberryplants Fruit-ripening-specificpectatelyase(Fruit-ripening-specificpectatelyase(果胶裂解酶果胶裂解酶)genehadbeensilenced)geneh

16、adbeensilencedn nNodifferencewasobservedinNodifferencewasobservedin color,shapeorweightcolor,shapeorweightn nCleardifferenceinfirmnessCleardifferenceinfirmnessn nMicroscopicanalysisofthefruitsMicroscopicanalysisofthefruits cellwallsintransgenicfruitsdisplayedalowercellwallsintransgenicfruitsdisplaye

17、dalowerdegreeofswellingthancontrolfruitsdegreeofswellingthancontrolfruits3.Methods for reducing spoilage in vegetables n nEdiblevegetablescomeinallshapes,Ediblevegetablescomeinallshapes,developmentalstagesandcolorsdevelopmentalstagesandcolorsn nLeafyvegetablesarethemosteconomicallyLeafyvegetablesare

18、themosteconomicallyimportanttypeimportanttype LettuceLettuceletisletis SpinachSpinach EndiveEndiveendaiv endaiv 菊莴苣菊莴苣菊莴苣菊莴苣 RadicchioRadicchio菊苣菊苣 WitloofWitloof菊苣菊苣 Reducing spoilage in vegetables n nEthylenereceptorEthylenereceptor EthyleneisintimatelylinkedtosenescenceanditsEthyleneisintimatelyl

19、inkedtosenescenceanditsroleasasenescenceinducerhasbeenfirmlyroleasasenescenceinducerhasbeenfirmlyestablishedestablished EthyleneinsensitiveplantsEthyleneinsensitiveplantsn nMutagenizeMutagenize（诱变）（诱变）todisruptethyleneperceptiontodisruptethyleneperceptionCytokinins(细胞分裂素细胞分裂素)n nAntagonistictoethyle

20、neAntagonistictoethylenen ndelayingtheonsetofsenescenceinleavesdelayingtheonsetofsenescenceinleavesn nDuringthesenescenceprocess,thereisaDuringthesenescenceprocess,thereisadropincytokininlevelsdropincytokininlevelsn nmanipulatecytokininbiosynthesistodelaymanipulatecytokininbiosynthesistodelaysenesce

21、nceinleavessenescenceinleaves BacterialgenecodingforenzymeforBacterialgenecodingforenzymeforbiosynthesisofcytokininsbiosynthesisofcytokinins CytokininslevelelevatedCytokininslevelelevated DelayinleafsenescenceDelayinleafsenescencen nTransgenicbroccoliTransgenicbroccoli carryingantisensecopiesofatoma

22、toACOgenecarryingantisensecopiesofatomatoACOgene Ethylenelowerthancontrols(72hafterEthylenelowerthancontrols(72hafterharvesting)harvesting)Respirationratedecrease(98hafterharvest)Respirationratedecrease(98hafterharvest)4.Enhancing plant resistance to fungal and bacteria n nOneofthemostpromisingresis

23、tanceOneofthemostpromisingresistancestrategiesstrategies useofcellwalllyticenzymestodegradeoruseofcellwalllyticenzymestodegradeordamagethefungalcellwalldamagethefungalcellwall Majorcomponents:chitinandglucanMajorcomponents:chitinandglucann nSeveralkindsofchitinasesandglucanasesSeveralkindsofchitinas

24、esandglucanaseshavenowbeenclonedhavenowbeenclonedn ntransgenicplantstransgenicplants anincreaseddegreeofresistancetofungalanincreaseddegreeofresistancetofungalpathogenspathogensn nbacterialresistanceisdifficulttoaccomplishbacterialresistanceisdifficulttoaccomplishSafety of Transgenic Foods/GMO/GEOn

25、nFDA1992Federal Register statementTheagencyisnotawareofanyinformationTheagencyisnotawareofanyinformationshowingthatfoodsderivedbythesenewshowingthatfoodsderivedbythesenewmethodsdifferfromotherfoodsinanymethodsdifferfromotherfoodsinanymeaningfuloruniformway,orthat,asameaningfuloruniformway,orthat,asa

26、class,foodsdevelopedbythenewtechniquesclass,foodsdevelopedbythenewtechniquespresentanydifferentorgreatersafetypresentanydifferentorgreatersafetyconcernthanfoodsdevelopedbytraditionalconcernthanfoodsdevelopedbytraditionalplantbreeding.plantbreeding.Regulatory process for transgenic crops in the U.S.n

27、 nInstitutional Biosafety Committeen nAnimal and Plant Health Inspection Service(APHIS)of USDAn nFood and Drug Administration(FDA)n nEnvironmental Protection Agency(EPA)GM Food Label Requiredn nEuropeanUnionsEuropeanUnions 10/2003:Labeling&traceability10/2003:Labeling&traceability 04/2004:EC1829/200

28、3&EC1830/200304/2004:EC1829/2003&EC1830/2003n nOthercountiesOthercounties Japan,Korea,China,Australia,NewZealand,Japan,Korea,China,Australia,NewZealand,IndiaIndian nMorethan35countrieshaveGMOMorethan35countrieshaveGMOregulationsunderconsiderationregulationsunderconsiderationProposed FDA policy for v

29、oluntary labelingNot genetically modifiedX Virtually all commercial foods have been genetically modified.GMO freeX “Free”implies zero,which is difficult to verify.Proposed FDA policy for voluntary labelingGenetically engineeredThis product contains cornmeal that was produced using biotechnology.This

30、 product contains high oleic acid soybean oil from soybeans developed using biotechnology to decrease the amount of saturated fat.OKOKUnderlined part is mandatory,Rest is voluntary.Proposed FDA policy for voluntary labeling(cont.)We do not use ingredients produced using biotechnology.OKThis oil is m

31、ade from soybeans that were not genetically engineered.OKMain Pointsn nWhatisclimactericandnon-climactericfruit?Whatisclimactericandnon-climactericfruit?n nWhatisthebiosynthesispathwayofethyleneinWhatisthebiosynthesispathwayofethyleneinplant?plant?n nListthemethodstoreducespoilageinfruitsandListthemethodstoreducespoilageinfruitsandvegetables.vegetables.n nWhatsyourattitudetotransgenicfoods?Whatsyourattitudetotransgenicfoods?The End