Plant hormones, also known as phytohormones, are chemical messengers that play a crucial role in regulating various physiological processes in plants. These hormones control everything from growth and development to responses to environmental stimuli such as light and temperature.
There are 5 main types of plant hormones: auxins, cytokinins, gibberellins, abscisic acid and ethylene. Each of these hormones has a specific function and interacts with the others to regulate plant growth and development.
AUXINS are a family of plant hormones that play a very important role in plant development. They are responsible for regulating cell elongation and root growth. They also promote fruit development and vertical growth.
CYTOKININS, on the other hand, promote cell division and delay the ageing of plant tissues. They also help to create adventitious roots and keep leaves green for longer. As well, they increase metabolic activity.
GIBERELLINS promote the growth of stems and leaves and are involved in the seed germination process. In addition, they help to facilitate fruit formation and trichome production. Gibberellins act as well to mitigate the effects of environmental stress factors on plants.
ABSCYSIC ACID helps plants cope with environmental stresses, such as drought, and regulates seed dormancy. This means that, unlike other hormones, it inhibits both seed and fruit growth.
Finally, ETHYLENE is involved in the development of female flowers and fruit ripening. It helps to survive in conditions of oxygen deficiency or high salinity and promotes senescence, i.e., the ageing and death of plant tissue. The main purpose of ethylene is to increase yield, improve plant adaptation and produce uniform crops.
The interaction between these hormones is complex and is regulated by various factors such as light, temperature and nutrient availability. Plant hormones are also influenced by external factors, such as pathogens and herbivores, which can trigger a response in the plant.
Understanding the role of plant hormones is crucial for plant breeding and agriculture. By manipulating the levels of certain hormones, it is possible to improve crop yields and increase resistance to environmental stresses such as drought and disease. Plant hormone research also has applications in other fields, such as medicine and biotechnology.