Chapter 22, Problem 27A

Summary Introduction

To write:The difference between ethylene and gibberellins and their relation.

Introduction:Plant hormones can influence division, growth, or differentiation of the cells. The plant hormones act by attaching chemically to the plasma membrane at certain sites called receptor proteins.

Explanation of Solution

The group of plant hormones known as gibberellins tends to cause elongation of the cells, promotes cell division and affects growth of seeds. Gibberellins are transmitted to vascular tissue. Dwarf plants also lack the gibberellins-protein receptor genes too. When treated with gibberellins, plants that lack the gibberellins genes but have receptors for gibberellins grow taller.

Ethylene is the primary known gaseous hormone. It is a simple compound which consists of two atoms of carbon and four of hydrogen. Ethylene is derived from plant tissues such as fruits, dyingleaves, and flowers that mature. Other parts of plants may be affected by ethylene; it primarily affects fruit maturing. Ethylene causes unripe fruit cell walls to weaken, and complex carbohydrates to split into simple sugars. Ethylene exposure results in fruits which are softer and sweeter than unripe fruits.

Gibberellins and Ethylene are both plant hormones.

Conclusion

Ethylene and gibberellins are both plant hormones. Gibberellins help in cell elongation, stimulate cell division and affect seed growth and affect ripening of fruit by ethylene.