Plant Biotechnology - iCEV Biotech 4

includes Introduction to Plant Biotechnology, Propagation, Genetic Engineering, and GMO Laws & Regulations

biotechnology

• a set of tools that uses living organisms or parts of organisms to

  • make or modify a product

  • improve plants or animals

  • develop microorganisms for specific uses

how long has plant biotechnology been used by humans?

several millennia

how long has plant propagation existed?

thousands of years

how long has plant breeding existed?

more than 10,000 years

genetic engineering

a plant biotechnology tool that describes certain methods used to introduce new traits or characteristics to an organism

what is the advantage of using recombinant DNA methods in genetic engineering?

allows plant scientists to develop crops quickly and more accurately with specific beneficial traits

genomics

a plant biotechnology tool that allows researchers to detect and map genes to discover their function

Marker Assisted Selection (MAS)

a plant biotechnology tool which allows the plant breeder to identify desirable genes with higher frequency and reduce the time necessary to produce an improved crop

what is the benefit of using MAS?

it can reduce the time necessary to produce an improved crop

what is happening to the demand for food?

it’s increasing dramatically as the world’s population grows

how can biotechnology help improve the demand for food?

with biotechnology, we can meet the growing demand without placing an even greater pressure on scarce resources

benefits of plant biotechnology

• improve plant productivity

• improve plant quality and health

• improve the quality of plant products

• prevent, reduce, or eliminate constraints to plant productivity caused by

  • diseases

  • pest organisms

  • environmental stresses

what is the ancient relative of corn that was domesticated through sexual propagation?

teosinte

key principles of plant breeding

• produce crosses by recombining existing genes

• produce varieties which breed true

• produce varieties which are useful

plant traits to consider when breeding

• improving plant yield

• improving product quality

• providing tolerance to stress

plant propagation

the process of taking a plant and making more of the same type of plant through either seeds, cuttings, or special techniques

what kind of offspring does utilizing cuttings create?

identical offspring to the mother plant

sexual reproduction

the creation of a new organism by combining the genetic material of two organisms

asexual reproduction

utilizes various methods to propagate new plants with an identical genetic makeup

characteristics incorporated into plant propagation

• disease resistance

• cold tolerance

• improved quality

• higher nutrient value

• quicker maturation

• ease of harvest

monocots

• one cotyledon

• floral parts in threes

• parallel leaf veins

• pollen grain has one pore or furrow

• vascular bundles throughout the stem’s ground tissue

examples of monocots

grass, corn, sorghum

dicots

• two cotyledons

• floral parts in fours or fives

• netlike leaf veins with a broader leaf

• pollen grain has three pores or furrows

• stem’s vascular bundles arranged as a ring

examples of dicots

oak trees, sunflower, bean

when did biotechnology initially develop in relation to agriculture?

not long after agriculture emerged

desired breeding outcomes

• larger plants

• larger fruit

• more plentiful harvests

• improved tolerance

budding

the process of taking a desirable clone (or bud) and attaching it to the stem; creates hybrid plants; differs from other types of grafting by using a single bud as scion material

what is the benefit of creating a hybrid plant?

can create a product that, for example, has a root system that is more desirable for the soil or drought or cold tolerance

grafting

joining parts from two or more plants so they appear to grow as a single plant

whip grafting

grafting technique used on small-diameter rootstock; very similar to splice grafting, whip grafting involves an additional cut, which allows the scion and rootstock to interlock

cleft grafting

used primarily with established fruit trees possessing a trunk or branch diameter greater than one inch; the technique involves splitting the stock and inserting one or two scions, which will develop into the new top of the plant

side grafting

generally used in larger, more developed fruit trees

layering

burying a stem under soil to force roots to form

simple layering

accomplished by bending a flexible and low-lying stem and covering with soil, leaving at least six inches uncovered

simple layering examples

climbing roses, forsythia, honeysuckle, azalea

tip layering

accomplished by bending and burying a currently developing shoot at least three inches deep

tip layering examples

raspberries and blackberries

compound layering

accomplished through the same method used for simple layering, with multiple parts of the stem being used to develop new plants

compound layering examples

wisteria, clematis, grapes

mound layering

accomplished through cutting plants to no less than one inch tall during dormancy and mounding soil over new plant shoots as they begin to grow

mound layering examples

apples, quince, magnolia

air layering

accomplished by making a cut into a developed stem, covering in sphagnum moss and protecting with either aluminum foil or plastic

air layering examples

rubber plants, azalea, camellia, magnolia

geophytes

an underground storage organ which resprouts by creating buds

separation

the process of separating plant parts by hand for artificial propagation

division

the process of separating plant parts with a knife for artificial propagation

bulbs

oval-shaped specialized underground plant storage structures which serve as organs and reproduce perennially; contain fleshy leaves

bulb examples

onions, tulips, easter lillies

corm

a solid bulblike mass of tissue which stores food, does NOT contain fleshy leaves

corm examples

taro, Chinese water chestnut, celery root, begonias

tubers

perennating organs which bear a bud and can produce a new plant

tuber examples

Irish potatoes

root sprouts

come from the root systems of already established plants

root sprout examples

live oaks

rhizome

horizontal stem which grows over and under the soil

rhizome examples

iris

genetic engineering

Allows for the movement of genes from any species into another species in a targeted way

Bacillus thuringiensis (Bt)

a naturally occurring bacterium living in soil which can produce Bt proteins which are toxic to insects; toxic to lepidopteran species and has been used for many years in organic farming

lepidopteran species include…

pests such as butterflies, whose larva can damage crops; Bt crops target these

steps to genetically modify crop

1. determine is genetic engineering is the best option

2. identify the gene of interest

3. make a copy of the gene from donor organism

4. introduce the gene into the DNA of the new plant

5. produce seed from the newly transformed plant

how do you make a copy of a gene from the donor organism?

use gene cloning (utilizing restriction endonucleases to cut DNA very specifically)

methods of introducing a gene into DNA of new plant

mechanical introduction and biological introduction

before introducing genetically engineered product to market, it must be…

• tested for consistency

• perform well in the field

• deemed safe

backcross breeding

the process of breeding a desired trait into the offspring of new plants; a parent plant with ideal traits is bred to another plant with one specific desirable trait, then the progeny is crossed back to the original parent

plant tissue culture (micropropagation)

a propagation technique used to maintain or grow plant cells, tissues, or organs under sterile conditions; used to produce clones

what are auxins and cytokinins?

hormones

auxins

induce growth in root tissues

auxins examples

naphthalene acetic acid (NAA), indolebutyric acid (IAA), indoleacetic acid (IBA)

cytokinins

induce shoot growth

cytokinins examples

benzylaminopurine (BAP), kinetin, zeatin

what must be ensured for developing tissue cultures?

protection

genetically modified crop uses include…

• vaccines

• pharmaceuticals

• nutraceuticals

what are PDPs?

GM plants that produce proteins essential for medical field

what is a drawback about medicinal products derived from plants?

they are not approved for use

what is the only component in plants approved for use?

a formula designed to address Vitamin B12 deficiency

what crop examples have been developed to produce vaccines?

potatoes, lettuce, wheat

what conditions have had plant-derived vaccines developed for them?

Hepatitis B, Norwalk Virus, H1N1 (swine flu)

Agrobacterium tumefaciens

a soil bacterium commonly used as a biological tool to transfer DNA into plant cells because it naturally inserts part of its DNA into plant genomes

callus

a mass of undifferentiated plant cells that forms in tissue culture when hormonal conditions are set to induce proliferation; from callus, shoots and roots can be regenerated.

germplasm

the genetic material (seed, tissue, or lines) of a species that contains the collection of genes breeders use to develop improved varieties; “elite germplasm” refers to high-performing genetic lines

gene cloning

laboratory methods used to make multiple identical copies of a specific gene or DNA fragment so it can be studied or inserted into another organism

gene gun

a mechanical method of introducing DNA into cells by coating tiny particles with DNA and shooting them into plant tissue so the DNA can integrate into the plant genome

genetic engineering

the process of directly altering an organism’s DNA to introduce, remove, or change specific genes so the organism expresses a desired trait (for example, inserting a gene from a bacterium into a plant so the plant produces an insect toxic protein)

transgenic

describes an organism that contains genetic material from a different species introduced through genetic engineering (e.g., a plant that expresses a bacterial gene)

scion

piece of plant tissue which is grafted onto the rootstock of another plant; is chosen for its desirable characteristics and will grow into the new top of the plant; may consist of several buds (grafting) or only one (budding)

cultivar

plant(s) selected for desirable characteristics that can be maintained by propagation; ex. height, drought resistance, petal shape, etc.

when was legislature established to regulate GMOs?

1986

principal regulatory agencies

• Animal and Plant Health Inspection Service (APHIS) (part of USDA)

• Environmental Protection Agency (EPA)

• Food and Drug Administration (FDA)

how long must we test a GE plant to assess it for regulation?

multiple years

what must we assess when testing a GE plant for regulation?

• potential to transfer the novel inserted trait to wild relatives (gene flow)

• potential effects or unintended consequences on other living organisms (ecological safety)

• potential toxicity and allergenicity of the proteins produced (safety)

what conditions are GE plants under while in the testing phase?

During the testing phase until fully deregulated by the government, all genetically engineered plants are grown as regulated material under permitted conditions and are subject to inspection

how are products regulated?

according to their intended use

are there labeling laws for GE plants or products?

no

before 2016, how was GMO labeling handled?

by the state

who is responsible for establishing rules about what foods must be labeled and standards for consistent labeling?

USDA

how does the FDA apply labeling to GE foods?

it applies the same labeling standards to GE foods as “natural” foods

why does federal law require labeling of a new food?

to inform consumers when there are significant changes in nutrition, safety or usage, or if the common name of the food no longer applies

when did the FDA issue draft guidance for food manufacturers who wish to use voluntary labels?

January 2001

how many crops for food consumption have been approved by the European Food Safety Authority?

49

Europe requires that imported food must be labeled as GE when they have what percent of GE crops in them?

more than 0.9%