Skip to main content

Plants insect resistance (Bt), virus resistance - coat protein, satellites, herbicide resistance. Increasing shelf life of foods flavr savr tomatoes, control of seed germination, genetically modified foods

Plants insect resistance (Bt), virus resistance - coat protein, satellites, herbicide resistance. Increasing shelf life of foods flavr savr tomatoes, control of seed germination, genetically modified foods



Introduction


Genetic engineering involves the direct manipulation of genes to introduce desirable traits into plants. Through recombinant DNA technology, plants can be made resistant to insects, viruses and herbicides, show delayed ripening, controlled seed germination, and improved nutritional quality. These advances have revolutionized agriculture and food security.

1. Insect Resistance in Plants – Bt Technology

Bt (Bacillus thuringiensis)
Bacillus thuringiensis is a soil bacterium that produces Cry (crystal) proteins toxic to insects.
Mechanism of Bt Insect Resistance
Bt gene (cry gene) is isolated and transferred into plant genome.
Bt protein is produced in plant tissues.
When insects feed on Bt plants:
Cry protein is activated in alkaline insect gut.
It binds to gut epithelial cells.
Pore formation occurs → gut rupture → insect death.

Examples of Bt Crops
Bt cotton
Bt maize
Bt brinjal


Advantages

Reduced chemical pesticide use
Target-specific action
Environmentally safe
Increased crop yield
Limitations
Development of insect resistance
Biosafety concerns


2. Virus Resistance in Plants

A. Coat Protein–Mediated Resistance (CPMR)
Principle
Gene encoding viral coat protein is introduced into plants.
Expression of coat protein interferes with virus uncoating and replication.


Mechanism
Prevents virus disassembly
Inhibits replication and movement within plant
Example
Tobacco resistant to Tobacco Mosaic Virus (TMV)
Papaya resistant to Papaya Ring Spot Virus (PRSV)

B. Satellite RNA–Mediated Resistance

Satellite RNAs
Small RNA molecules dependent on helper viruses for replication.
Do not encode proteins.
Mechanism
Compete with viral genome for replication machinery.
Reduce viral multiplication and symptom severity.

Application

Used in virus-infected crops to reduce disease severity.

3. Herbicide Resistance in Plants


Definition

Herbicide-resistant plants tolerate specific herbicides that kill weeds but not the crop.
Methods
Modification of target enzyme
Introduction of herbicide-degrading genes.

Example

Glyphosate resistance via modified EPSP synthase gene.
Bar gene confers resistance to phosphinothricin

Advantages
Efficient weed control
Reduced tillage
Increased productivity
Limitations
Development of super weeds
Environmental concerns

4. Increasing Shelf Life of Foods – Flavr Savr Tomato


Flavr Savr Tomato
First genetically modified food approved for human consumption (1994).
Principle
Delayed fruit softening by inhibiting polygalacturonase (PG) enzyme.
Technique
Antisense RNA technology used to suppress PG gene expression.
Result
Slower cell wall degradation
Delayed ripening
Extended shelf life
Advantages
Improved storage and transport
Reduced post-harvest losses


5. Control of Seed Germination

Importance
Prevents premature germination (vivipary)
Synchronizes germination
Enhances seed storage life
Genetic Control
Manipulation of genes regulating abscisic acid (ABA) and gibberellic acid (GA).
Increased ABA → inhibits germination
Reduced GA → delays germination.


Applications

Crop management
Hybrid seed production
Storage stability

6. Genetically Modified Foods (GM Foods)


Definition

GM foods are foods derived from organisms whose genetic material has been altered using genetic engineering.

Examples

Golden rice (vitamin A enrichment)
Bt corn
Flavr Savr tomato
Herbicide-resistant soybean


Advantages

Improved nutritional quality
Enhanced shelf life
Pest and disease resistance
Reduced chemical usage


Concerns


Allergenicity
Gene transfer
Ethical and environmental issues


Conclusion
Genetic engineering has provided powerful tools to improve crop protection, yield, storage and nutritional quality. Technologies such as Bt insect resistance, virus resistance, herbicide resistance and delayed ripening contribute to sustainable agriculture and food security. However, careful evaluation, biosafety regulations and public awareness are essential for safe adoption of genetically modified foods.




MCQs: Genetic Engineering in Plants & GM Foods
1. Bt toxin is produced by
A. Bacillus subtilis
B. Bacillus thuringiensis
C. Agrobacterium tumefaciens
D. Pseudomonas fluorescens
Answer: B
2. Bt toxin proteins are also known as
A. Vip proteins
B. Cry proteins
C. Cap proteins
D. Shock proteins
Answer: B
3. Bt toxin becomes active in
A. Acidic gut of insects
B. Alkaline gut of insects
C. Neutral gut of mammals
D. Plant cytoplasm
Answer: B
4. Bt toxins kill insects by
A. Blocking respiration
B. Inhibiting protein synthesis
C. Creating pores in gut epithelium
D. Preventing molting
Answer: C
5. First commercially grown Bt crop in India
A. Bt maize
B. Bt rice
C. Bt cotton
D. Bt brinjal
Answer: C
6. Virus resistance through coat protein is known as
A. RNA interference
B. Antisense technology
C. Coat protein–mediated resistance
D. Satellite RNA resistance
Answer: C
7. Coat protein–mediated resistance works by
A. Killing virus particles
B. Preventing virus uncoating
C. Destroying host cell
D. Blocking transcription
Answer: B
8. First successful example of CPMR was in
A. Tomato
B. Tobacco
C. Potato
D. Papaya
Answer: B
9. Papaya Ring Spot Virus resistance was achieved using
A. Satellite RNA
B. Coat protein gene
C. Herbicide gene
D. Antisense RNA
Answer: B
10. Satellite RNAs are
A. Viral proteins
B. Independent viruses
C. Small RNAs dependent on helper virus
D. Bacterial plasmids
Answer: C
11. Satellite RNAs reduce viral infection by
A. Killing host cells
B. Enhancing viral replication
C. Competing with viral genome
D. Producing toxins
Answer: C
12. Herbicide resistance in plants allows
A. Weeds to grow faster
B. Crops to survive herbicide application
C. Herbicide breakdown in soil
D. Killing of beneficial microbes
Answer: B
13. Glyphosate targets which enzyme?
A. Rubisco
B. EPSP synthase
C. Nitrate reductase
D. ATP synthase
Answer: B
14. Herbicide resistance is achieved by
A. Removing plant enzymes
B. Modifying target enzyme
C. Stopping photosynthesis
D. Increasing respiration
Answer: B
15. Bar gene provides resistance to
A. Glyphosate
B. Paraquat
C. Phosphinothricin
D. Atrazine
Answer: C
16. Flavr Savr tomato shows
A. Faster ripening
B. Early seed germination
C. Delayed softening
D. Increased acidity
Answer: C
17. Flavr Savr tomato was developed using
A. RNAi
B. Antisense RNA technology
C. Gene knockout
D. CRISPR
Answer: B
18. Polygalacturonase enzyme is involved in
A. Protein synthesis
B. Cell wall degradation
C. Photosynthesis
D. Respiration
Answer: B
19. Delayed ripening in Flavr Savr tomato results in
A. Reduced shelf life
B. Extended shelf life
C. Faster spoilage
D. Poor taste
Answer: B
20. First genetically modified food approved for consumption
A. Golden rice
B. Bt corn
C. Flavr Savr tomato
D. GM soybean
Answer: C
21. Control of seed germination involves regulation of
A. Cytokinin only
B. Auxin only
C. ABA and GA
D. Ethylene only
Answer: C
22. Abscisic acid mainly
A. Promotes germination
B. Inhibits germination
C. Promotes flowering
D. Increases fruit ripening
Answer: B
23. Gibberellic acid mainly
A. Inhibits germination
B. Stops cell division
C. Promotes germination
D. Induces dormancy
Answer: C
24. Premature germination in seeds is called
A. Dormancy
B. Stratification
C. Vivipary
D. Scarification
Answer: C
25. Control of seed germination is useful in
A. Reducing crop yield
B. Hybrid seed production
C. Increasing weed growth
D. Decreasing storage life
Answer: B
26. Genetically modified foods are produced by
A. Traditional breeding
B. Hybridization
C. Recombinant DNA technology
D. Mutation breeding only
Answer: C
27. Golden rice is enriched with
A. Vitamin C
B. Vitamin A
C. Vitamin D
D. Vitamin K
Answer: B
28. GM foods help in
A. Increased chemical pesticide use
B. Reduced shelf life
C. Improved nutritional quality
D. Soil degradation
Answer: C
29. One major concern related to GM foods is
A. Increased yield
B. Reduced pesticide use
C. Allergenicity
D. Improved storage
Answer: C
30. Bt crops reduce
A. Herbicide use
B. Chemical insecticide use
C. Fertilizer use
D. Water requirement
Answer: B
31. Cry genes are originally isolated from
A. Viruses
B. Fungi
C. Bacteria
D. Plants
Answer: C
32. Insect resistance in plants mainly targets
A. Mammals
B. Birds
C. Insect pests
D. Microbes
Answer: C
33. Herbicide-resistant crops help in
A. Weed survival
B. Selective weed control
C. Soil erosion
D. Reduced yield
Answer: B
34. Satellite RNAs cannot
A. Replicate independently
B. Reduce virus severity
C. Depend on helper virus
D. Interfere with virus replication
Answer: A
35. Antisense RNA works by
A. Enhancing gene expression
B. Blocking mRNA translation
C. Increasing enzyme activity
D. Producing toxins
Answer: B
36. Which hormone promotes seed dormancy?
A. Auxin
B. Gibberellin
C. Abscisic acid
D. Cytokinin
Answer: C
37. Herbicide-resistant crops may lead to
A. Super weeds
B. Increased biodiversity
C. Reduced resistance
D. Crop sterility
Answer: A
38. Which GM crop is widely cultivated globally?
A. Bt cotton
B. Flavr Savr tomato
C. Golden rice
D. GM potato
Answer: A
39. Virus-resistant transgenic plants reduce
A. Nutritional value
B. Viral multiplication
C. Plant growth
D. Seed production
Answer: B
40. Bt toxin genes are expressed in
A. Roots only
B. Leaves only
C. All plant tissues
D. Selectively in tissues
Answer: D
41. CPMR mainly interferes with
A. Virus attachment
B. Virus uncoating
C. Host DNA replication
D. Cell division
Answer: B
42. Genetic engineering helps in shelf life extension by
A. Increasing ethylene production
B. Slowing fruit softening
C. Increasing respiration rate
D. Increasing water loss
Answer: B
43. GM foods are regulated mainly due to
A. Cost
B. Taste
C. Biosafety issues
D. Yield improvement
Answer: C
44. Herbicide resistance is often transferred using
A. Plasmids
B. Ribosomes
C. Lysosomes
D. Vacuoles
Answer: A
45. Cry proteins are toxic to
A. All organisms
B. Humans
C. Specific insect groups
D. Plants
Answer: C
46. Flavr Savr tomato reduces
A. Post-harvest losses
B. Photosynthesis
C. Flowering
D. Seed number
Answer: A
47. Genetic modification in seed germination helps to
A. Induce vivipary
B. Prevent vivipary
C. Increase seed spoilage
D. Reduce dormancy
Answer: B
48. Which is NOT a GM food example?
A. Golden rice
B. Bt corn
C. Flavr Savr tomato
D. Hybrid wheat
Answer: D
49. Virus resistance in plants improves
A. Disease susceptibility
B. Crop productivity
C. Weed growth
D. Seed dormancy
Answer: B
50. Main goal of genetic engineering in plants is
A. Increased chemical dependency
B. Sustainable agriculture
C. Reduced yield
D. Soil pollution
Answer: B

Comments

Post a Comment

Popular Posts

Secondary Databases (PROSITE, PRINTS, BLOCKS)

Secondary Databases (PROSITE, PRINTS, BLOCKS  Secondary Databases Introduction Biological databases are broadly classified into primary and secondary databases. Primary databases store raw experimental data (e.g., nucleotide or protein sequences), whereas secondary databases contain derived information obtained by analyzing primary sequence data. Secondary databases are mainly used to: Identify protein families Detect conserved motifs, patterns, and domains Predict protein function Study structure–function relationships Examples of secondary databases include PROSITE, PRINTS, BLOCKS, Pfam, etc. 1. PROSITE Database Definition PROSITE is a secondary database that documents protein domains, families, and functional sites in the form of patterns and profiles. Developed by Swiss Institute of Bioinformatics (SIB) Maintained along with UniProt Principle PROSITE is based on the idea that functionally important regions of proteins are conserved during evolution. These conserved regions can ...
Post a Comment
Read more

••CLASSIFICATION OF ALGAE - FRITSCH

      MODULE -1       PHYCOLOGY  CLASSIFICATION OF ALGAE - FRITSCH  ❖F.E. Fritsch (1935, 1945) in his book“The Structure and  Reproduction of the Algae”proposed a system of classification of  algae. He treated algae giving rank of division and divided it into 11  classes. His classification of algae is mainly based upon characters of  pigments, flagella and reserve food material.     Classification of Fritsch was based on the following criteria o Pigmentation. o Types of flagella  o Assimilatory products  o Thallus structure  o Method of reproduction          Fritsch divided algae into the following 11 classes  1. Chlorophyceae  2. Xanthophyceae  3. Chrysophyceae  4. Bacillariophyceae  5. Cryptophyceae  6. Dinophyceae  7. Chloromonadineae  8. Euglenineae    9. Phaeophyceae  10. Rhodophyceae  11. Myxophyce...
Post a Comment
Read more

Fourth Semester M.Sc. Degree Examination, March 2021Time: 3 HoursBotanyBO 241: BIOINFORMATICS AND BIOPHYSICS(2019 Admission)

Fourth Semester M.Sc. Degree Examination, March 2021 Time: 3 Hours Botany BO 241: BIOINFORMATICS AND BIOPHYSICS (2019 Admission) 1. Answer the following questions. 1. Expand EMBL and DDBJ. 2. What do bootstrap values indicate? 3. What is multiple sequence alignment? 4. What is SNP? 5. Define transcriptome. 6. What is Smith Waterman algorithm? 7. Comment on Phylip. 8. What are the factors that determine the electrophoretic mobility of a particle? 9. Differentiate between resolution and resolving power of the microscope. 10. Which are the factors that determine the sedimentation of a component during centrifugation? (10 x 1= 10 Marks) II. Answer the following questions in not more than 50 words. 11. (a) What is the difference between rooted and unrooted phylogenetic tree? OR (b) What is ORF? What is its significance in functional genomics? 12. (a) Explain the use of GENSCAN. OR (b) Explain the assumptions in molecular clock hypothesis. 13. (a) Write a brief explanation on KEGG. OR (b) Co...
Post a Comment
Read more

Intellectual Property Rights (IPR) – Detailed Notes

Intellectual Property Rights (IPR) – Detailed Notes 1. Introduction Intellectual Property Rights (IPR) are legal rights granted to creators and inventors over their creations or inventions. They protect innovation and creativity, providing the owner exclusive rights to use, sell, or license their creation. IPR encourages research, development, and economic growth by rewarding creativity. 2. Importance of IPR Protects inventions, designs, and creative work. Prevents unauthorized use, copying, or commercialization. Encourages innovation and research. Provides financial benefits to inventors through licensing or royalties. Supports economic growth and competitiveness. Safeguards traditional knowledge and biodiversity. 3. Types of Intellectual Property Rights A. Patents Definition: Exclusive right granted to an inventor for a new invention for a limited period (usually 20 years). Requirements: Novelty – must be new and not published. Inventive step – non-obvious to someone skilled in the f...
Post a Comment
Read more

❥ Southern Blotting Notes

Southern Blotting  ❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥ 𓆞❥  Introduction Southern blotting is a molecular biology technique used for the detection of specific DNA sequences in a complex mixture of DNA. It was developed by Edwin M. Southern in 1975. The method involves restriction digestion of DNA, separation by gel electrophoresis, transfer (blotting) onto a membrane, and hybridization with a labeled DNA probe. Principle of Southern Blotting The technique is based on the principle of complementary base pairing. A single-stranded labeled DNA probe hybridizes specifically with its complementary DNA sequence immobilized on a membrane. Detection of the label confirms the presence and size of the target DNA fragment. Steps Involved in Southern Blotting. 1. Isolation of DNA Genomic DNA is extracted from cells or tissues. DNA must be pure and intact to ensure accurate results. 2. Restriction Enzyme  Digestion DNA is digested using specific restriction endonucleases. Produces DNA f...
1 comment
Read more

Electroporation – Detailed Notes

Electroporation – Detailed Notes Definition : Electroporation is a physical method of gene transfer in which cells are exposed to a brief, high-voltage electric pulse, creating temporary pores in the cell membrane. This allows DNA, RNA, proteins, or other molecules to enter the cytoplasm. It is widely used in bacteria, yeast, plant protoplasts, and mammalian cells. Key Concept: The electric field destabilizes the membrane, making it permeable to macromolecules. 1. Principle Cells are suspended in a conductive medium. A brief electrical pulse induces transient pores in the plasma membrane. DNA or other molecules present in the medium enter the cell through these pores. Membrane reseals after the pulse, and the molecule is retained inside the cell. Advantages of Principle: Direct and rapid. Works in many cell types. Does not require chemical carriers or viral vectors. 2. Materials Required Cells – bacterial, yeast, plant protoplasts, mammalian cells. DNA/RNA/other macromolecule – purifie...
Post a Comment
Read more

Third Semester M.Sc. Degree Examination, January 2023 Botany BO 231 PLANT BREEDING, HORTICULTURE AND BIOSTATISTICS

Third Semester M.Sc. Degree Examination, January 2023 Botany BO 231 PLANT BREEDING, HORTICULTURE AND BIOSTATISTICS Time: Three Hours (2019 Admission Onwards) I. Answer the following questions. 1.What is green super rice? 2.What are the functions of ICAR-NBPGR? 3.Give the importance of floral biology in plant breeding. 4.How do you develop a synthetic variety? 5.Where can you find gene-for-gene relationships? 6.Describe the significance of biodiversity policy. 7.What is Olericulture? 8.Describe the advantages of in door garden. 9.What is Students's t-test? 10. Explain Ogive graph. (10 × 1 = 10 Marks) 11.Answer the following questions in not more than 50 words . 11. (a) Explain hybridization and mention it's procedure. OR (b) Write short notes on the concept of centers of origin proposed by Vavilov. 12. (a) Describe cytoplasmic male sterility and its uses. OR (b) Explain the role of interspecific and intergeneric hybridization. 13. (a) What is seed certification? How is it done? ...
Post a Comment
Read more

Third Semester M.Sc. Degree Examination, February 2024 231: PLANT BREEDING, HORTICULTURE AND BIOSTATISTICS

Third Semester M.Sc. Degree Examination, February 2024                 Botany BO 231: PLANT BREEDING, HORTICULTURE AND BIOSTATISTICS (2019 Admission onwards) Time: 3 Hours I.Answer the following questions. 1.What is atomic gardening? 2.Name the cardamom research institute in Kerala. 3.Explain advantages of distant hybridisation. 4.Describe plant variety rights. 5.Write short notes on arboriculture. 6.What is vermicomposting? 7.Give short notes on cut flower industry. 8.What is ANOVA? 9.Describe the properties of binomial distribution. 10. Explain the use of LSD. Max. Marks: 75 (10 x 1 = 10 Marks) II.Answer the following questions in not more that 50 words. 11. (a) What do you mean by genetic modification techniques? OR (b) What is center of diversity of a species? 12. (a) Compare auto and allopolyploidy. OR (b) What are requirements of back cross breeding? 13. (a) Describe ideotype breeding and its significance. OR (b) What is the role of seed cer...
Post a Comment
Read more

❃LC-MS (LIQUID CHROMATOGRAPHY – MASS SPECTROMETRY)

LC-MS (LIQUID CHROMATOGRAPHY – MASS SPECTROMETRY)  ┏━━━━━ •❃°•°❀°•°❃•━━━━•━━━┓ 1. INTRODUCTION LC-MS is a hyphenated analytical technique combining Liquid Chromatography (LC) and Mass Spectrometry (MS). It is used for separation, identification, and quantification of compounds in complex mixtures. LC separates analytes based on polarity, size, or charge, while MS detects molecules based on mass-to-charge ratio (m/z). Developed in the 1970s–1980s, LC-MS is now widely used in pharmaceutical, clinical, environmental, and food analysis. Importance : Detects trace levels of compounds (ng–pg range) Analyzes non-volatile, thermally labile compounds that cannot be analyzed by GC-MS Provides structural information through mass fragmentation Example: Detection of drugs in plasma, protein identification in proteomics, pesticide residue analysis in food. 2. COMPONENTS OF LC-MS The LC-MS system has three main parts: A. Liquid Chromatograph (LC) Function: Separates components of a mixture befor...
Post a Comment
Read more

Fourth Semester M.Sc. Degree Examination, June 2022BotanySpecial Paper II - ElectiveBO 242 a: BIOTECHNOLOGY

Reg. No.: Name: N-6273 Fourth Semester M.Sc. Degree Examination, June 2022 Botany Special Paper II - Elective BO 242 a: BIOTECHNOLOGY Time: 3 Hours (2019 Admission Onwards) Max. Marks: 75 1. Instruction: Draw diagrams and illustrate with examples wherever necessary. Answer the following questions. 1. What are the desirable features of a cloning vehicle? 2. What is a palindrome? 3. What is the significance of Ori C site? 4. What is the actual function of restriction enzymes in a bacterial system?  5.Name any two bacteria and fungi used for alcohol fermentation. 6. What is a starter culture? 7. What are adapters? 8. What are probes? 9. What is biopiracy? 10. Define cybrids. (10 x 1 = 10 Marks) II. Answer the following questions in not more than 50 words .  11. (a) Why is callus culture a prerequisite for somaclonal variations? OR (b) How is virus elimination done via plant tissue culture? 12. (a) How is aeration maintained in a bioreactor? OR (b) What are the methods available f...
Post a Comment
Read more