Environmental Sensing in Plants: Phototropism and Rhythms

post midterm 6

Active form (PFR)

phytochrome form activated by red light

biological clocks

internal mechanisms regulating circadian rhythms

chloroplast movements

movement of chloroplasts in response to light

circadian rhythms

biological cycles occurring roughly every 24 hours

day-neutral plants

flowering unaffected by day length

elongation growth

increase in length of plant tissues

entrainment

synchronization of biological clocks to environmental cycles

florigen

chemical signal inducing flowering in plants

flowering time

time of flowering based on environmental cues

FT protein

phloem-mobile signal for flowering induction

genetic drift

random changes in allele frequencies in population

germination

process of seed sprouting and growth

gibberellins

hormones promoting seed germination and growth

inactive form (PR)

phytochrome form activated by far-red light

induction of flowering

process triggering flowering in plants

light receptors

molecules that detect light signals

long day plants (LDP)

flower when nights are shorter than a critical length

photodormancy

seed dormancy influenced by light conditions

photomorphogenesis

developmental changes in plants due to light

photoperiods

duration of light and dark periods

phototropism

plant growth response to light direction

phytochromes

photoreceptors responding to red and far-red light

polar cell growth

differential expansion in plant cells

precision agriculture

using technology to optimize farming practices

seasonal responses

plant adaptations to seasonal changes

shade avoidance syndrome

growth response to neighboring plant shading

short-day plants (SDP)

flower when nights exceed a critical length

transgenic tobacco

genetically modified tobacco for phytochrome expression

urban evolution

adaption of species in urban environments

vertical farming

growing crops in vertically stacked layers