EnvReg213-page5 - to close the trap once the insect touches...

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Plant Environmental Regulators - 5 A thigmonastic stimulus can travel throughout the leaf and the plant. In plants with compound leaves, the stimulus can touch one leaflet, but the response is progressive throughout the leaf and to other leaves as well. Electrical action potentials have been measured, and rate of transmission is about 1cm/second. Venus flytrap leaves respond to touch in a similar way. Action potentials travel from the trigger hairs to the mesophyll cells that are compressed and under tension when the trap is open. Turgor changes swell the cells, closing the trap. The biochemical process behind this is unknown, but it takes less than one second
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Unformatted text preview: to close the trap once the insect touches the trigger hairs. Thigmomorphogenesis Plants have a more compact and sturdy growth pattern (called habit) when subjected to mechanical stimuli such as wind, rain (rain drops have weight) and the occasional touch by passersby. The famous Monterey Cypress is a photogenic example of the effect of prevailing winds on plant growth. A Ca ++ mediated signal transduction pathway activates genes that alter the growth patterns. Response to twice-daily touch (on left) Monterey cypress...
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