[lyka_candelario]

Ethylene actually has a lot of interesting properties. It’s a gaseous plant hormone with a very simple molecular structure. It is referred to as the aging hormone in plants. But even so, it can actually cause plants to die, which is why the fruits need to be harvested first.

Ethylene is known to be used as a ripening agent even by the ancient Egyptians for figs. The Chinese used it for pears. Also, during 1864, it was discovered that gas leaks from street lights caused the triple response which are unusual thickening of stems, twisting of plants, and stunting of plant growth. It was only in 1901 that a Russian scientist found out that the gas was in fact ethylene. In 1934, Gane made a report about plants synthesizing the chemical. A year after, Crocker hypothesized that ethylene was a kind of plant hormone beneficial for fruit ripening and can inhibit vegetative tissues.

Nowadays, ethylene is known to have several plant processes, it stimulates:
• Fruit ripening
• Leaf and flower senescence
• Flower opening
• Bromeliad flower induction
• Fruit and leave abscission
• Adventitious root formation
• Root and shoot growth
• Release of dormancy

Factors to consider in a plant’s responsiveness to ethylene are: a) the crop, b) the plant development stage, c) temperature, d) ethylene concentration, e) exposure duration. It is utilized for the ripening of bananas, tomatoes, pears, and other fruits after harvest.

Aside from Ethylene, there are other plant hormones (phytohormones) known to affect plant growth. Three other kinds are the:
1. Abscisic acid – chemical compound found in freshly fallen leaves, produced usually when plant is under stress, most important plant growth regulator, causes bud dormancy, slows down cell growth in mature plant areas
2. Auxins – compounds influencing cellular enlargement, root initiation, and bud formation, control fruit, stem, and root growth, convert stem into flowers, regulate seed protein synthesis
3. Cytokinins – group of chemicals affecting cell division and also shoot formation, delay aging, influence leaf length and growth, synergizes with auxins

Knowing such mechanisms sparks my interest about a plant’s overall process. We already are mesmerized by the human body’s course, but finding out about a plant’s internal networks is a good discovery for today! I’ll never see a plant the same way again.