Negative plageotropism : Negative plageotropism
Phototropism : Phototropism
Phototropism : Phototropism Geotropism
Phototropisms : Phototropisms Phototropic responses involve bending of growing stems toward light sources.
Individual leaves may also display phototrophic responses.
Auxin most likely involved
Positive Phototropism in stems : Positive Phototropism in stems
Thigmotropic or Haptotropic : Thigmotropic or Haptotropic In response to touch or contact stimulus
Eg. Response of Tendrils
Plants Respond toTouch : Plants Respond toTouch Thigmotropism Directional growth response to contact with an object.
Tendrils
Thigmotropism : Thigmotropism
Hydrotropic : Hydrotropic In response to water stimulus
Eg. Roots
Chemotropic
Fungal hyphae
And movement of
pollen tubes
Thermotropic : Thermotropic Seedlings curve towards WARM side
Nastic Movements : Nastic Movements Not in direction of environmental fluxes
Photonastic : Photonastic Day and Night movements
Flowers of Oxalis open in morning and close at night
Thermonastic : Thermonastic In response to high temperatures
Flowers of Crocus and Tulip open only at high temperatures
Tulips open in response to warm temperature : Tulips open in response to warm temperature
Crocus open in response to warm temperature : Crocus open in response to warm temperature
NYCTINASTY : NYCTINASTY Sleep movements
Prayer plant (Maranta euconeura)
lower leaves during the day and raises leaves at night
Shamrock (Oxalis)
Legumes
Nyctinasty in Oxalis : Nyctinasty in Oxalis
SEISMONASTY - a nastic response resulting from contact or mechanical shaking Mimosa pudica L. (sensitive plant) : SEISMONASTY - a nastic response resulting from contact or mechanical shaking Mimosa pudica L. (sensitive plant)
Nastic Movement : Nastic Movement Movement independent of direction of stimulus
Anatomically predetermined direction rather than towards or away
Response to environmental stimuli
Shaking can cause change in other parts of plant like in the sensitivity plant
leaflets close and stems droop
Pulvinus of Mimosa pudica : Pulvinus of Mimosa pudica
What is THIGMONASTY or HAPTONASTY ? : What is THIGMONASTY or HAPTONASTY ? The pictures projected on this free session belong to the beholder on the internet. We thank them
Haptonastic Movements in Insectivore plants, Venus fly trap : Haptonastic Movements in Insectivore plants, Venus fly trap Have trigger hairs on lobes of plant
Must touch 2 hairs consecutively
Snaps shut, trapping whatever stimulated the closing
Slide 24 : Nastic movements have an adaptive significance
Scare off insects and hard to see to eat when leaves are folded
Slide 25 : THE END Thanks to Dr. Subroto Biswas as ever
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