Bt brinjal

ATMA RAM MEENA
Ph.D HORICULTURE
SKRAU, BIKANER

2. BIOSAFETY CONCERNS
SEVERAL—Scientific
Economic
Social
Ethical
Moral

3. RISK TO HUMAN HEALTH
•Risk of toxicity
•Risk of allergies
•Antibiotic resistance
•Eating foreign DNA
•Changes in nutritional level

4. Bt Technology
•TheuseofBacillusthurigiensistocontrol
insect-pestsisnotnew
•WhatisnewinBtcropsisthatamodified
versionofthebacterialCrygenehasbeen
incorporatedintotheplant'sownDNA
•Plant'scellularmachineryproducesthe
delta-endotoxin,aspartoftheplant's
normaldevelopment.

5. INSECTICIDAL CRYSTAL PROTEINS PRODUCED BY
INDIVIDUAL Bacillus thuringiensisSTRAINS
Btstrain Crystal protein
kurstaki Cry1, Cry2, Cry11
aizawai Cry1, Cry9, Cry39, Cry40
entomocidus Cry1, Cry11
galleriae Cry1, Cry7, Cry8, Cry9
israelensis Cry10, Cry11
japonensis Cry8, Cry9
jegathesan Cry11, Cry19, Cry24, Cry25
kenyae Cry1, Cry2
kumamotoensis Cry7, Cry8
morrisoni Cry1, Cry3
tanebrionis Cry3
Tolworthi Cry3, Cry9
wuhanensis Cry1
Slater etal. (2003)
Bacillus thuringienesis-Anaturally occurring,
Gram-positive soil bacterium
Genetic engineering of crops with
Bt gene(s)has now revolutionized the
application of Bt for insect-pest
management

6. Bt CRYSTAL PROTEIN GENE FAMILY
CryGENE FAMILIES PROTEIN SIZE (kDa) SUSCEPTIBLE INSECT
PEST
Cry1(A-K) 81-140 Lepidoptera
Cry2A 70-71 Lepidoptera
Cry3(A-C) 73-75 Coleoptera
Cry4(A-B) 128-135 Diptera
Cry5(A-B) 135-152 Nematodes
Cry6(A-B) 44-53 Nematodes
Cry7A 127 Coleoptera
Cry8(A-D) 128-130 Coleoptera
Cry9(A-D) 130-132 Lepidoptera
Cry10A 78 Diptera
Cry11(A-B) 72-81 Diptera
Cry12-40 Various Various
Slater et al. (2003)

7. Action of Bt on caterpillars
1)Caterpillar consumes foliage treated with Bt2)Within minutes, toxin binds to specific
receptors in the gut wall, and caterpillar stops feeding 3)Within hours, gut wall breaks
down, allowing Btspores and normal gut bacteria to enter the body cavity; the toxin
dissolves 4)Within couple of days, the caterpillar dies as spores proliferate in its blood
1
2
3
4

8. Will insects become resistant to Bt toxins?
•Bthasbeenusedasabiologicalinsecticideforover30years
asasprayandtherehasbeenlittleopportunityforinsectsto
evolveresistance
•Plantscontainingasingleinsectresistancetransgeneplanted
commerciallybygrowers
•BtICPswillbeproducedcontinuallyinplanttissue
•Creationofstrongselectionpressureonbotheconomically
importantandunimportantinsects
•IfgenesconferringresistancetoBtbecomefixedininsect
populations,bothspraysandtransgenicplantswouldbecome
ineffectiveasinsectcontrolagents

9. Is Btsafe for humans
•Toxicityvsallergicreaction
•Agenciesresponsiblefortheregulationoftransgenicplants
intheU.S.,ie.USDA,APHIS,EPA,FDA.
BtRegistrationActionDocumentEPA'sreview@
www.epa.gov/scipoly/sap:Humanhealthassessment,
environmentalassessment,outcrossing,non-targetspecies,
fateinsoilsandindirecteffectsonsoilorganisms,pollen
toxicity,sheddingandmovement.
•ProductsderivedfromBtcotton,cornandpotatoesaresafe
forhumanandanimalconsumption(USEPABiopesticide
SafetySheets;Betzetal.,2000)

10. RISK TO ENVIRONMENT
•Persistence of transgene/transgene product
•Interaction with nontarget organisms
•Unprerdictable gene expression or transgene
instability
•Gene flow
•Resistance/tolerance of target pests
•Increased weediness
•Loss of biodiversity
•Changes in soil ecology
•Generation of new viruses

11. Damage to environment
•Crop to weed gene flow
•Antibiotic resistance to soil micro-organisms
•Leakage of GM proteins into soil

13. Regulatory frame work in India
1. Recombinant DNA Advisory Committee (RDAC)
2. Review Committee on Genetic Manipulation (RCGM)
3. Genetic Engineering Approval Committee (GEAC)
4. Institutional Biosafety Committee (IBSC)
5. State Biosafety Coordination Committee ( SBCC)
6. District Level Committees (DLC)

14. ...IBSC approval with a copy to RCGM...
A. Greenhouse : IBSC approval with a copy to RCGM
B. Event selection trial in field –RCGM approval
Gene Discovery
Cloning
Construct
Transformation
INDIAN REGULATORY SYSTEM FOR DEVELOPMENT AND RELEASE OF
TRANSGENIC CROPS
Number of Events

15. RCGM
BRL-1Fieldtrial:–withapermissionfromRCGMplusbiosafety
dossier(Proteinthermalstability,pepsindigestibility,acuteoralsafety
limitstudy,pollenflowstudy,agronomicevaluation)– To be
approvedbyRCGM.
GEAC
BRL-11–Fieldtrial:WithpermissionfromGEACplussubchronic
feedingstudyinrodents+livestockfeedingstudy(optional).
Commercialization:Fulldossier.

16. THANKS FOR PATIENCE