The MUTE gene encodes instructions for a cellular protein that can control the "on" or "off" state of other plant genes. The researchers created a strain of Arabidopsis that can artificially produce a lot of the MUTE protein, so they could easily identify which genes the MUTE protein turned on or off. They discovered that many of the activated genes control cell division -- a process that is critical for stomatal development. In Arabidopsis, as in nearly all plants, stomata form from precursor cells known as guard mother cells, or GMCs.
To form a working stoma -- singular for stomata -- a GMC divides once to yield to paired guard cells. Since their data showed that MUTE proteins switched on genes that regulated cell division, Torii and her team wondered if MUTE is the gene that activates this single round of cell division.
If so, it would have to be a tightly regulated process. The genetic program would have to switch on cell division in the GMC, and then quickly switch it right back off to ensure that only a single round of division occurs. Through precise experiments, they gathered data on the timing MUTE activation of these cell division activators and repressors. They incorporated this information into a mathematical model, which simulated how MUTE acts to both activate and repress cell division in the GMC.
Materials provided by University of Washington. Note: Content may be edited for style and length. Science News. Plants know how to do a neat trick. To form a working stoma — singular for stomata — a GMC divides once to yield to paired guard cells. Since their data showed that MUTE proteins switched on genes that regulated cell division, Torii and her team wondered if MUTE is the gene that activates this single round of cell division.
If so, it would have to be a tightly regulated process. The genetic program would have to switch on cell division in the GMC, and then quickly switch it right back off to ensure that only a single round of division occurs. Through precise experiments, they gathered data on the timing MUTE activation of these cell division activators and repressors.
They incorporated this information into a mathematical model, which simulated how MUTE acts to both activate and repress cell division in the GMC. For more information, contact Torii at or ktorii uw. If you're trying to subscribe with a non-UW email address, please email uwnews uw.
UW News. Search UW News Search for:. For UW employees Submission guidelines Submission form. Some plants have very small leaves and photosynthesis takes place in the bark or stems.
The raw materials of photosynthesis consist of six water molecules 6H 2 0 and six carbon dioxide 6CO 2 molecules. In most plants, the roots absorb water from the soil.
The water travels up through the xylem, a specialized layer of cells. In some plants, the water is absorbed through the leaves, directly from the air. Carbon dioxide, an atmospheric gas, enters the leaf through the stomata, the tiny pores in the leaves a stoma is a single pore. When water enters directly from the atmosphere, it also enters the leaf through stomata.
These raw materials travel into the chloroplasts in the spongy and palisade layers of the leaf. The chemicals react, using the sun's energy absorbed by the chlorophyll in the chloroplasts. The chemical reaction of photosynthesis results in one sugar molecule glucose: C 6 H 12 O 6 and 6 oxygen pairs 6O 2.
Plants store the glucose and release the oxygen as a waste product, with most of the oxygen leaving the plant through the stomata. Each stoma the tiny pore or hole is flanked by two guard cells which expand and contract, closing and opening the stoma. Two controls on the opening and closing of the stomata are the plant's water balance and the carbon dioxide concentration.
When the plant becomes dehydrated and wilts, the closing of a plant's stomata will retain water.
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