Photo: Eugene Vadim epanchitsev / RIA Novosti
MSU scientists have proved that a dangerous active oxygen species, which are often seen as a byproduct of energy production in the cell, the required coniferous plants for sexual reproduction. The study is published in the journal Plant Reproduction. Press release article is available at the disposal “of the Tape.ru”.
Cones conifers are dioecious, with male cones are relatively small and form pollen which is carried by the wind, and the female is large, they form eggs. Reaching the female cones, pollen grains stick on a special liquid (pine and spruce) or sticky hairs (Douglas fir). Then the pollen grain begins to germinate, forming a pollen tube through which male gametes reach the egg to fertilize it.
Photo: Maria Bragina / MSU
It is known that families have a key role in germination of finger grain playing reactive oxygen species (ROS), which are formed as a byproduct of photosynthesis and respiration and can damage membranes, DNA and other cell components. In cells, ROS can be used as signals that promote the activation of certain processes.
Physiologists of plants of Moscow state University found that the pollen grain secretes hydrogen peroxide and superoxide before germination. As a result, in pollen tube forms a gradient of hydrogen peroxide the concentration of which increases towards the tip. It turned out that this gradient is needed for the tube growth to the ovule, as well as to maintain the membrane potential.
Also found a protein that controls this process. It appeared to be of NADPH-oxidase located in the membrane of cells and responsible for transferring electrons from cells and the formation of superoxide on the outer side. The latter becomes a peroxide, which is back in the cage. Hydrogen peroxide is distributed in the pollen tube along the gradient. It is shown that the suppression of the NADPH-oxidase of pollen grain may not germinate and fertilization becomes impossible.
Video, photo All from Russia.