Cytokiini
Cytokinins are a class of plant hormones that play a crucial role in various physiological processes, including cell division, differentiation, and growth. They were first identified in the 1950s and are known for their ability to promote cell division and delay senescence, the natural aging process of cells. Cytokinins are synthesized in the roots and transported to other parts of the plant via the xylem. They are involved in numerous processes such as shoot and root growth, leaf expansion, and flowering. The most well-known cytokinins are zeatin (Z), zeatin riboside (ZR), and isopentenyladenine (iP). Cytokinins interact with other hormones, particularly auxins, to regulate plant growth and development. Their activity is mediated through specific receptors on the cell membrane, leading to various downstream signaling pathways. Cytokinins are essential for plant survival and reproduction, making them a vital area of study in plant biology and agriculture.