Seed Plant Final Vocab

cultivation

cultivation

behaviors involved in managing plant resources (clearing, burning, plowing, selective breeding, planting, and harvesting)

domestication

type of evolution in which selection occurs under human influence

artificial selection

an evolutionary process in which humans consciously select for or against particular features

genetic engineering

modify the genes to enhance the capabilities of the organism beyond what is normal

transgene

an artificial, manipulated gene, that incorporate all appropriate elements critical for gene expression, derived from a different species

CRISPR

a technology to selectively modify the DNA/ edit the genes of living organisms

transient expression

the production of a recombinant protein over a short period (1–14 days) following DNA transfer (temporary expression of genes)

molecular farming

the production of pharmaceutically important and commercially valuable proteins in plants (instead of food, feed, or fiber)

medicinal products

substances or combination of substances that is intended to treat, prevent or diagnose a disease

secondary metabolites

substances manufactured by plants that make them competitive in their own environment

major developmental hormones

Six main types: Auxins, abscisic acid (ABA), cytokinins, ethylene, gibberellin (GA), and brassinosteroids (BR)

defensive hormones

regulate plant defence to pathogens →salicylic acid (SA) and jasmonic acid (JA) (sometimes ethylene and ABA)

polar transport

directional cell-to-cell transport of functional molecules, enables plants to sense and respond to developmental and environmental signals

PIN proteins

drive directional auxin flow through their polar localization within the cell

apical dominance

central stem of the plant is dominant over (i.e., grows more strongly than) other side stems

conjugation

the transfer of DNA in a site- and strand-specific manner from a donor to a recipient cell (typically in bacteria)

biosynthesis

the process by which living things use chemical reactions to create products useful for cellular metabolism

• the final products are macromolecules

catabolism

the set of metabolic processes that break down large/ complex molecules

senescence

the gradual deterioration of functional characteristics (like aging)

triple response

an adaptation that enables seedlings to overcome obstacles, such as debris, and successfully emerge into the light during germination

expansins

small extracellular proteins that promote turgor-driven extension of plant cell walls

phosphorelay

aids phosphoryl group transfer to initiate a change in cell state or activity

auxin

• involved in cell elongation

• can change the pH of the wall, allowing the wall to expand

• has a nucleus receptor

• directly alters cell physiology

• can release repression

• involved in leaf abscission (fall off in fall)

cytokinin

• involved in cell division

• natural & synthetic types

• in RAM →lateral bud stimulated apical dominance, stimulates leaf expansion, delays leaf senescence, enhances stomatal opening (in some species)

• has a plasma membrane receptor

• involved in a signaling cascade, phosphorelay to release repression

ethylene

• gaseous hormone

• promotes fruit ripening

• homeostasis is controlled by biosynthesis → triple response: reduced elongation, hypocotyl swelling, apical hook exaggeration

• involved in leaf abscission (fall off in fall)

• has an ER receptor

• involved in a signaling cascade

• can release repression

abscisic acid (ABA)

• synthesized in chloroplasts (plastids) of leaves

• water regulating

• inhibits shoot growth and effect of gibberellins (GA)

• can be inactivated through oxidation & conjugation

• water stress promotes signaling

• releases into cytoplasm when needed

• plasma membrane and cytosolic receptors

• directly impacts transcription factors

• release of repression (if snRK2 pathway is present)

• direct physiological impact → tugor pressure and ion channels

• calcium & nitric oxide signaling cascades

Gibberellins (GA)

• promotes germination

• induces maleness in dioecious flowers

• induces fruit development w/out seeds

• biosynthesis occurs in specific tissue

• excess GA stimulates GA-inactivating enzymes

• directly impacts expansin enzymes -. stimulates cell elongation

• nucleus receptor

• release repression

Brassinsteroids (BA)

• steroid hormone, specifically paracrine

• promote shoot growth (along w/ auxin)

• differentiation of vascular development

• transportation isn’t a big deal

• excess BR stimulates BR-inactivating enzymes

• conjugation allows for some reversible storage

• Low BR → BIN2 is active (p)

• High BR → BSU1 and BSK5 are active(p) (BIN is removed and transcription is activated)

• plasma membrane receptor

• phosphorelay

• release repression

tropism

the movement of plants or their parts in a particular direction in response to an external stimulus

phototropism

the growth of an organism in response to a light stimulus

phototropin

the blue light receptor for phototropism

• an indicator of “good” light

gravitropism

the growth of the plant in a specific direction in response to gravity

• positive gravitropism ex.→ roots

• negative gravitropism ex.→ stems

starch-statoliths

specialized starch-containing plastids (amyloplasts), found in the root cap

sense gravity

hydrotropism

the growth of plant structures towards (+) or away (-) from moisture

thigmotropism

the growth of a plant in response to movement or touch

thigmomorphogenesis

the response by plants to touch, to alter their growth patterns

circadian rhythm

a natural cycle of behavior and physical changes which repeats daily

• is regulated

• anticipates daily occurences

cryptochrome

a photoreceptor that is sensitive to blue light and regulates the circadian rhythm

phytochrome

a class of photoreceptor proteins that respond to red light and far-red light

• control many aspects of plant development (like germination)

photoperiodism

the physiological reaction of organisms to the length of light or a dark period (can be daily or seasonal)

etiolation

the process in which plants grow long, pale and unhealthy due to lack of light

dormancy

the state of a plant when growth, development, and physical activity are temporarily stopped

nastic movements

non-directional responses to stimuli that occur rapidly (ex. sensitive mimosa plant)

thigmonastic movement

non-directional response to touch (a type of nastic movement)

pulvini solar tracking

the orientation of a plant towards the sun and following it throughout the day

done by pulvini, a joint-like structure which can cause movement of plant organs via changes in turgor

heliotropism

the directional growth of a plant in response to sunlight