Angiosperm Reproduction and Biotechnology

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The grain triticale is derived from a successful cross between wheat and rye.

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Plant Biotechnology and Genetic Engineering

Plant biotechnology has two meanings:

In a general sense, it refers to innovations in the use of plants to make useful products.

In a specific sense, it refers to use of GM organisms in agriculture and industry.

Modern plant biotechnology is not limited to transfer of genes between closely related species or varieties of the same species.

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Reducing World Hunger and Malnutrition

Genetically modified plants may increase the quality and quantity of food worldwide.

Transgenic crops have been developed that:

Produce proteins to defend them against insect pests

Tolerate herbicides

Resist specific diseases.

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Biofuels are made by the fermentation and distillation of plant materials such as cellulose. Biofuels can be produced by rapidly growing crops and reduce dependency on fossil fuels.

Nutritional quality of plants is being improved. “Golden Rice” is a transgenic variety being developed to address vitamin A deficiencies among the world’s poor.

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“Golden Rice” and prevention of blindness associated with vitamin A deficiency

Genetically modified rice

Ordinary rice

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The Debate over Plant Biotechnology

Some biologists are concerned about risks of releasing GM organisms into the environment:

One concern is that genetic engineering may transfer allergens from a gene source to a plant used for food.

Many ecologists are concerned that the growing of GM crops might have unforeseen effects on nontarget organisms.

The most serious concern is transgene escape = the possibility of introduced genes escaping into related weeds through crop-to-weed hybridization.

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Efforts are underway to prevent this by introducing:

Male sterility

Apomixis

Transgenes into chloroplast DNA (not transferred by pollen)

Strict self-pollination.

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Review

Endosperm

nucleus (3n)

(2 polar nuclei

plus sperm)

Zygote (2n)

(egg plus sperm)

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You should now be able to:

Describe how the plant life cycle is modified in angiosperms.