Trees and Autumn 1 (2/6)

The leaves contain a number of pigments, but chlorophyll is predominant during the warm seasons, so in the spring and summer the trees are green leaves. At the end of the summer and early autumn in the plants begins to synthesize a hormone called the axin which causes the growth of a special layer of surface cells, called a “layer of the leaves”. By reducing sunshine during this period of the year, plants respond to a dim daylight. In the end, after passing a certain limit, the production of axin is terminated. The sudden change in the amount of the hormone allows the base of each leaf handle to form a layer of cells that interrupt the supply of water and mineral salts to the leaf. In addition, carbohydrates from the leaves to the rest of the plant are also discontinued. When this happens, the leaves can no longer reproduce chlorophyll, and it gradually collapses.