Plant Hormones and Tropisms Flashcards
proteins activated by specific signals; can be found in the plasma membrane, nucleus, and endoplasmic reticulum
receptors
series of relay proteins or enzymes; amplify and transform the signal to one that the cell can understand
transduction pathway
result of the transduction pathway; the transcription of genes or product of a metabolic pathway
cellular response
chemical signals produced in very low concentration and cause the response to the stimuli
plant hormones
growth toward a stimulus
positive tropism
growth away from a stimulus
negative tropism
permits plant to bend in the direction of sunlight; synthesized at the stem tips; movement is downwards
auxins
necessary for plant germination; nurtures internodes’ elongation
gibberellins
result of multiple attempts of growth; promotes cell division; produced in the root apical meristem; movement is upwards; counters senescence
cytokinins
a gas formed from the amino acid, methionine. it is involved in abscission and fruit ripening
ethylene
plant growth in response to a light stimulus
phototropism
plant growth in response to touch or contact with a solid object
thigmotropism
this type of growth occurs when the cells in one area of a plant organ, such as stem or root, grow more quickly than the cells in the opposite area
differential growth
growth or movement response of a cell or an organism to gravity
geotropism/gravitropism
growth or movement in response to water concentrations
hydrotropism
growth or movement in response to chemicals
chemotropism
growth or movement in response to heat or temperature changes
thermotropism
growth or movement in response to darkness
skototropism
