Plant Hormones Flashcards
plant hormones ____ be active at their site of synthesis
can
Plant hormones
chemicals that are produced by the plant which act as signals that alter growth and/or development
what determines whether a hormone will affect that cell or tissue
the sensitivity of the target and concentration of hormones
5 classical plant hormones
auxins
cytokinins
gibberellins
ABA (abscisic acid
ethylene
what do auxins do
promote stem elongation, root growth, phototropism, and gravitropism (expansion of cells)
what do cytokinins do
growth regulators
important for cell division
what do gibberellins do
regulators of stem elongation
what do ABA (abscisic acid) do
the stress hormone
involved in seed development, maturation, dormancy, and plant stress
what does ethylene do?
fruit ripening and senescence
how was hormone function identified
by observing the role of the coleoptile tip on blue-light induced phototropism
what is cell expansion caused by
increases in turgor pressure/weakening of the cell wall
what are expansins
proteins that loosen the hydrogen bonds between cell wall polysaccharides
what hormone makes the plant bend
auxin
