Why do trees always grow toward light?

(Scientists from the Carnegie Institution Research Institute at Stanford University and the University of Wageningen have discovered how cells in the stalks grow with seeds using blue light (blue light) to develop toward the light.

During previous studies, discoveries were made: cells in stems grown in seeds that reacted with blue light were used in microscopes.

Scientists have now discovered how blue light produces small structures in cells, tubular microstructures , to grow vertically with their normal developmental direction. As a result, the direction of development of seed crops also changes, making them towards the light. Scientists have discovered which proteins are responsible for the development of vertical tubular microstructures in the normal direction.

The research results have been published in the journal Science.

Most of us know, the plants grown by seeds grow towards the light. But do they do that? It is a question that many scientists have struggled to clarify for years.

In studies before this study, scientists observed the cells of plants grown with seeds. Using special microscopes with blue laser light, they made important structures for the development of plant cells visible to the naked eye. Some surprises have occurred: within 10 minutes, the microscopic arrangement of microstructures has changed completely under a microscope.

Through the use of image analysis techniques, scientists were able to show that within minutes, blue light resulted in a large number of new generation of tubular microstructures, located perpendicular to the pre-existing tubular microstructures . They also found that the way cells in grain plants detect light under these conditions is through phototropin , a protein that allows plants to detect light.

In addition, it is determined that a large number of tubular microstructures are vertical with previously existing microtubules caused by katanin protein . Plants grown with katanin-free seeds cannot produce changing directions of microtubules and cannot grow toward light.

Katanin is activated by phototropin and can sever the microtubules in place but they cross other microtubules. Cutting off results in two microtubules developing in the same direction. The microtubules located perpendicular to the old microtubules create a lot of intersections. Whenever new microtubules intersect with other microtubules in the original direction, katanin can cut new microtubules to create new branches. Within a few minutes, this results in the inner microtubules located perpendicular to the original direction.

The growth and growth of plants depends strongly on the quantity and quality of the light source they find. Plants depend on light for photosynthesis, but they cannot move themselves. Instead, they develop toward the light. This study shows that the re-establishment of microtubules plays an essential role in this process.

The research is supported by the NSF Award Carnegie Science Research Institute and many other organizations.