make healthy popcorn corn. colorful too - Your Published Bio Team Output

Bioteam
**Pre-Project**To make healthy popcorn corn, adding or adjusting metabolic pathways would be most appropriate, as the objective is to increase the nutritional content of the corn. One potential subspecies to consider is the Glass Gem corn, which is known for its vibrant and diverse colors.

To make the corn more nutritious and colorful, the following modifications could be investigated:

1. Increase the production of anthocyanins: Anthocyanins are pigments that give fruits and vegetables their red, purple, and blue colors. They are also a type of flavonoid that has antioxidant properties. By increasing the production of anthocyanins in the corn, the kernels could have a more vibrant and varied color, while also providing potential health benefits for the consumer.

2. Increase the production of carotenoids: Carotenoids are pigments that give fruits and vegetables their yellow, orange, and red colors. They are also precursors to vitamin A, which is important for eye health and immune function. By increasing the production of carotenoids in the corn, the kernels could have a brighter yellow or orange color, while also providing added nutritional value.

3. Increase the production of fiber: Popcorn is already a good source of fiber, but by increasing the production of certain types of fiber, such as resistant starch or beta-glucans, the corn could provide even greater health benefits. Resistant starch has been shown to improve digestive health and lower the risk of Type 2 diabetes, while beta-glucans can help lower cholesterol levels.

Overall, adjusting the metabolic pathways to increase the production of these nutrients would be the best approach to make healthy and colorful popcorn corn.

**Genes:** 4. Increase the expression of the lycopene beta-cyclase gene: The lycopene beta-cyclase gene is involved in the conversion of lycopene, a red carotenoid pigment, into beta-carotene, a yellow-orange carotenoid pigment. By increasing the expression of this gene, the corn kernels could have a more varied and bright color, as well as potentially higher levels of beta-carotene, which has been linked to reduced risk of chronic diseases.

5. Increase the expression of the zeaxanthin epoxidase gene: Zeaxanthin is a carotenoid pigment that is important for eye health. The zeaxanthin epoxidase gene is involved in the conversion of zeaxanthin into another carotenoid called violaxanthin. By increasing the expression of this gene, the corn kernels could potentially have higher levels of zeaxanthin, providing added nutritional value and potential health benefits.

6. Increase the expression of the alpha-tocopherol gene: Alpha-tocopherol is a form of vitamin E that has antioxidant properties and is important for health. By increasing the expression of the gene that produces alpha-tocopherol, the corn kernels could have higher levels of this nutrient, providing added benefits to the consumer.

7. Increase the production of polyphenols: Polyphenols are a type of antioxidant found in plant-based foods. By increasing the production of polyphenols in the corn kernels, the popcorn could provide added health benefits, such as reduced inflammation and improved cardiovascular health. One possible gene to target would be the phenylalanine ammonia-lyase gene, which is involved in the biosynthesis of many different types of polyphenols.

**Regulatory Elements:** Ideal promoter sequences:
1. The Zm13 promoter from the maize (Zea mays) alcohol dehydrogenase 1 gene: This promoter has been shown to be active in developing kernels and could be used to drive the expression of the lycopene beta-cyclase, zeaxanthin epoxidase, and alpha-tocopherol genes specifically in the corn kernels.

2. The Zm13W8 promoter from the maize W8 gene: This promoter has also been shown to be active in developing kernels and could be used to drive the expression of the desired genes specifically in the kernels.

3. The CaMV 35S promoter from the Cauliflower mosaic virus: This is a strong, constitutive promoter that could be used to drive the expression of the desired genes in all parts of the corn plant, including the kernels.

Enhancer sequences:
1. The maize polyubiquitin 1 enhancer: This enhancer has been shown to increase the expression of genes in developing maize kernels specifically.

2. The rice actin promoter enhancer: This enhancer has been shown to enhance gene expression in developing rice seeds, and could therefore be effective in enhancing gene expression specifically in corn kernels.

3. The soybean β-conglycinin enhancer: This enhancer has been shown to enhance gene expression in soybean seeds, and could potentially be effective in enhancing gene expression in corn kernels as well.

Terminator sequences:
1. The nopaline synthase terminator from Agrobacterium tumefaciens: This is a commonly used terminator that has been shown to terminate gene expression effectively.

2. The pea ribulose-1,5-biphosphate carboxylase small subunit terminator: This terminator has been shown to be effective in terminating gene expression in developing pea seeds, and could therefore be effective in terminating gene expression in corn kernels.

3. The wheat heat shock protein 17.3 terminator: This terminator has been shown to be effective in terminating gene expression in wheat seeds, and could potentially be effective in corn kernels as well.

These regulatory elements will enhance the desired outcome for each gene and its expression by driving their expression specifically in the kernels, enhancing their expression levels in the kernels, and effectively terminating their expression once they have fulfilled their function. The use of these regulatory elements could lead to the production of healthier and more colorful popcorn corn, with higher levels of beta-carotene, zeaxanthin, alpha-tocopherol, and polyphenols.

**Vector & Delivery:** Delivery Method:

To optimize the desired genetic modifications, a particle bombardment method like biolistic transformation would be appropriate for delivering the gene construct into the corn kernels. This method is advantageous as it can deliver the desired genes directly into the corn kernels, bypassing the need for plant regeneration, and plant transformation can be accomplished in a shorter time compared with Agrobacterium-mediated transformation. In using the particle bombardment method, gold or tungsten particles coated with the desired cassette would be shot into the corn kernels, where they would be taken up by the plant cells.

This method optimizes desired genetic modifications because the cassette can be delivered directly to the corn kernels, resulting in less tissue damage and higher transformation rates. The kernel-specific promoters used in the cassette will ensure that the genes are expressed only in the kernel, where their effects are desired, leading to a healthier and more colorful popcorn variety. Overall, the biolistic transformation method would be an appropriate and effective method for delivering the gene cassette that would optimize the desired genetic modifications.

**Selection Marker:** Selection Marker:

To facilitate the selection and identification of successfully modified organisms, a selectable marker gene such as the neomycin phosphotransferase gene (nptII) can be included in the cassette. The nptII gene confers resistance to the antibiotic kanamycin and is commonly used as a selectable marker in plant transformation studies.

By including the nptII gene in the cassette, only those corn kernels that have successfully taken up and integrated the cassette into their genome will be resistant to kanamycin. Therefore, by selecting for kanamycin-resistant kernels, researchers can identify and isolate the successfully transformed plants.

Additionally, since the nptII gene does not affect the properties of the corn kernels, its inclusion in the cassette will not interfere with the desired genetic modifications. Overall, the use of the nptII gene as a selectable marker will facilitate the selection and identification of successfully modified organisms without interfering with the desired genetic modifications or the properties of the popcorn corn.

**Transformation Protocol:** Protocol for Biolistic Transformation of Popcorn Corn:

Materials:

- Gold or tungsten particles (1-3 µm)
- Biolistic PDS-1000/He Particle Delivery System (or equivalent)
- Gene cassette containing the desired genes (lycopene beta-cyclase, zeaxanthin epoxidase, alpha-tocopherol, and phenylalanine ammonia-lyase), kernel-specific promoters (Zm13 or Zm13W8), enhancer sequences (maize polyubiquitin 1 or rice actin promoter, or soybean β-conglycinin), a selectable marker gene (neomycin phosphotransferase II), and terminator sequences (nopaline synthase, pea ribulose-1,5-biphosphate carboxylase small subunit, or wheat heat-shock protein 17.3)
- Sterile distilled water
- 70% ethanol
- Sterile Petri dishes
- Sterile forceps
- Tweezers
- Sterile tubes

Procedure:

1. Sterilize the gold or tungsten particles by incubating them in 70% ethanol for 30 minutes. Rinse the particles 3 times with sterile distilled water and transfer them to a sterile Petri dish.

2. Coat the particles with the gene cassette by adding 10 µg of cassette to the particles and drying them under a stream of nitrogen.

3. Place the corn kernels on a sterile Petri dish and spray them with 70% ethanol. Allow the ethanol to evaporate and transfer the kernels to a fresh sterile Petri dish.

4. Set up the Biolistic PDS-1000/He Particle Delivery System following the manufacturer's instructions.

5. Load the gene cassette-coated particles into the cartridge and attach it to the Biolistic PDS-1000/He Particle Delivery System.

6. Place the Petri dish with the corn kernels on the sample stage of the Biolistic PDS-1000/He Particle Delivery System.

7. Adjust the pressure and distance according to the manufacturer's instructions and shoot the particles into the corn kernels.

8. Incubate the kernels at 28°C for 48 hours.

9. Select for transformed kernels by transferring them to fresh media containing kanamycin (50 mg/L). Incubate at 28°C with a 16-hour photoperiod for 1-2 weeks.

10. Perform PCR analysis to confirm the presence of the desired genes in the transformed kernels.

11. Evaluate the corn kernels for color, nutritional content, and antioxidant properties.

Precautions:

- All equipment and materials should be sterilized to avoid contamination.
- The gene cassette should be handled with care to avoid accidental release or inhalation of the DNA.
- The Biolistic PDS-1000/He Particle Delivery System should be operated according to the manufacturer's instructions.
- The selection marker should be used only for in vitro selection and should not be present in the final product.
- The transformed plants should be evaluated for potential unintended effects on their morphology, physiology, or ecology.

**Gene casette**: Final Cassette:

5' - Zm13 promoter - Gene of interest (lycopene beta-cyclase/zeaxanthin epoxidase/alpha-tocopherol/phenylalanine ammonia-lyase) - maize polyubiquitin 1 enhancer - nptII selectable marker - terminator sequence (nopaline synthase/pea ribulose-1,5-biphosphate carboxylase small subunit/wheat heat shock protein 17.3) - 3'

The cassette would be suitable for cloning into a plant transformation vector such as pCAMBIA or pBIN19, which contains the appropriate promoters, enhancers, and terminator sequences for expression and regulation of the genes of interest. The biolistic method of transformation using gold or tungsten particles coated with the cassette would allow for targeted delivery to the developing corn kernels, ensuring that the genetic modifications are expressed specifically in the kernels.

The inclusion of the selectable marker gene nptII in the cassette allows for the selection and identification of successfully transformed corn plants without interfering with the desired genetic modifications or the properties of the popcorn corn. The use of the Zm13 promoter and maize polyubiquitin 1 enhancer will drive the expression of the genes of interest specifically in the corn kernels, while the terminator sequence will effectively terminate gene expression once their function is fulfilled.

Overall, the final cassette, delivery method, and selection marker provide an effective and optimized approach for the desired genetic modifications of increasing the expression of the lycopene beta-cyclase, zeaxanthin epoxidase, alpha-tocopherol, and phenylalanine ammonia-lyase genes, and increasing the production of polyphenols in popcorn corn kernels.

**Paper Abstract:** This paper proposes using genetic engineering approaches to enhance the color and nutritional value of popcorn corn. The study aims to increase the expression of four genes involved in the biosynthesis of carotenoids, vitamin E, and polyphenols, all of which have potential health benefits. The paper identifies several regulatory elements, including promoter and enhancer sequences, that could be used to drive the expression of these genes specifically in the corn kernels. The chosen delivery method, biolistic transformation, involves the direct delivery of the gene cassette into the corn kernels, bypassing the need for plant regeneration. A selectable marker gene, nptII, will be added to identify the transformed plants. The use of these genetic modifications could lead to the production of healthier and more colorful popcorn corn, with higher levels of beta-carotene, zeaxanthin, alpha-tocopherol, and polyphenols.

**Growth, Selection & Stabilization:** Growth, Selection, and Stabilization Protocol:

1. For growth and selection, the corn seeds should be surface sterilized by treating them with 70% ethanol and 1% sodium hypochlorite for 5 minutes each. They should then be rinsed several times with sterile distilled water to remove any traces of the sterilizing agents.

2. The sterilized corn seeds should be plated on a Murashige and Skoog (MS) nutrient medium that contains appropriate concentrations of plant growth regulators like benzylaminopurine (BAP) and naphthaleneacetic acid (NAA) that promote callus formation.

3. Incubate the plates at 25°C under a 16-hour light/8-hour dark cycle for callus formation. This can take up to 2 weeks.

4. Once callus formation is evident, the callus tissue should be bombarded with the gene constructs using a particle gun coated with the cassette.

5. The bombarded callus tissue should then be transferred to a selection medium containing kanamycin, and incubated under the same conditions as before until resistant calli start to form.

6. The resistant calli should be carefully transferred to fresh medium periodically to promote regeneration.

7. After regeneration, the plants need to be transferred and grown in soil under controlled environmental conditions in a greenhouse. The environmental conditions should be optimized for the best possible growth of the modified plants.

8. Once the plants have matured, the kernels from the modified plants should be harvested, and their colors and nutritional values compared to the unmodified control.

9. Stabilization of the modified organisms can be achieved by crossbreeding the plants to generate homozygous plants that carry the desired genetic modifications.

10. Homozygous plants should be grown and monitored in a controlled environment to ensure that the desired genetic modifications are stably inherited through successive generations, leading to the production of a healthy and nutritionally improved popcorn variety.

Overall, the growth, selection, and stabilization protocol outlined above, when followed meticulously, can result in healthy and nutritionally improved popcorn variety. The optimized environmental conditions will ensure proper growth and development of the modified plants, while the selection and stabilization steps promote the inheritance of the desirable genetic modifications through successive generations.

**Proliferation Method:** Once the stable transformants have been generated using the biolistic transformation method, they can be proliferated using tissue culture techniques. Specifically, the transformed corn kernels can be germinated on selective media containing kanamycin to further select for the successful transformants. The selected transformants can then be propagated by tissue culture techniques such as shoot proliferation or somatic embryogenesis, which can result in the generation of large numbers of genetically identical plants.

To ensure efficient proliferation and maintain the desired genetic modifications in the resulting population, careful monitoring and maintenance of the tissue culture conditions is crucial. This includes ensuring that the tissue culture media is properly formulated with the appropriate nutrients, growth regulators, and antibiotics to maintain the health and growth of the transformed corn, and regular monitoring for any signs of contamination or stress.

In addition, it may be necessary to periodically confirm the maintenance of the desired genetic modifications in the proliferated population. This can be achieved through PCR or other molecular genetic techniques to confirm the presence of the desired genes and regulatory elements.

Overall, the use of tissue culture techniques can facilitate the efficient and rapid proliferation of the stable transformants while maintaining the desired genetic modifications in the resulting population.

**Conclusion:** In conclusion, the proposed genetic engineering approach for enhancing the color and nutritional value of popcorn corn offers a promising solution for creating healthier and more appealing popcorn. The biolistic transformation method offers a direct and efficient way of introducing the desired genes into the corn kernels, while tissue culture and genetic stabilization techniques ensure the maintenance and inheritance of the genetic modifications. The use of a selectable marker gene allows for the identification of successfully transformed plants without affecting the expression or properties of the desired genetic modifications. The optimized cassette and regulatory elements offer specific expression of the genes of interest in the corn kernels, while the termination sequence ensures controlled gene expression. The resulting popcorn corn with higher levels of beta-carotene, zeaxanthin, alpha-tocopherol, and polyphenols may have significant health benefits and nutritional value. Further research could explore additional genes or regulatory elements to optimize the popcorn variety and adapt this approach to other crops. Overall, this project demonstrates a successful application of genetic engineering approaches for crop improvement and highlights the potential for using biotechnology for sustainable agriculture and food production.