The plant heals damage done to the root, due to the pressure drop inside the cells near the wound, reported in the Proceedings of the National Academy of Sciences. These cells begin to actively secrete the hormone auxin, it acts on the transcription factor ERF115 and this determines which planes will divide and grow new cells needed to restore the lost tissues.
When the integrity of the body of the animal is disturbed (in other words, it hurt), the place of damage are cells of the immune system and stem cells. They sterilize the wound and regenerate the lost tissue volume. Plant cells can’t move: prevents thick walls made of cellulose that surrounds them. In addition, the walls of adjacent cells firmly connect to each other. So to heal the damage we have to use a different strategy.
Plant cells lying in the immediate vicinity of the wound, lose their specialization and become educational (components of wound meristem), whose descendants can become part of the fabric of any desired type. To return to the site of injury of the former, they have to stretch and share in some directions more and more often, than in others. What and how to coordinate the division and growth of cells in wound meristem was not completely understood, but it is known that root growth and its separate parts regulates plant hormone auxin.
Physiologists of plants from the Austrian Institute of science and technology, headed Frimley jiří (Jiří Friml) tried to figure out the details of healing plants on the example of the popular model of the object, Arabidopsis, or rezhevichi, talya (Arabidopsis thaliana). To do this, they scatter the laser damaged the roots of Arabidopsis and then a few hours watching the healing in real time.
Plants that are used in the experiments were transgenic: they, unlike reshoved wild-type, was expressed the green fluorescent protein gene linked with the gene of the transcription factor ETHYLEN-RESPONSIVE 115 (ERF115). It is known that ERF115 produced in cells near wounds, but not in the normal meristems, and is active in the kernel (as it controls the formation of RNA copies of different genes, and it is predominantly a nuclear process).
In addition to green fluorescent protein root cells have developed a complex of substances that is linked to another fluorescent protein Tdtomato. The structure of this complex was varied under the influence of auxin, so that the illumination of Tdtomato could be seen only in cells that produce much of this hormone. The change in fluorescence, the researchers could understand which cells are involved in wound healing.