Which of the following is a symptom of exposure to ethylene gas?

Ethylene gas is a natural plant hormone that plays a significant role in the ripening of fruits and the aging of flowers. Its effects can cause a range of symptoms in plants.

Flower and petal drop occurs as ethylene promotes senescence, or the natural aging process, leading to the premature abscission of flowers. This can drastically affect the visual appeal and longevity of floral arrangements.

Wilting is another symptom related to ethylene exposure. The gas can disrupt the normal water regulation within plants, leading to a loss of turgor and resulting in wilting. This decreased water retention can cause flowers to appear dull and lifeless.

The loss of foliage is also associated with exposure to ethylene. The hormone can trigger leaf drop as part of the senescence process. When leaves are shed prematurely, the plant's ability to photosynthesize and maintain health is compromised.

Given that all these symptoms—flower and petal drop, wilting, and loss of foliage—are directly linked to exposure to ethylene gas, the correct choice encompasses all of these effects. Understanding these symptoms is crucial for anyone working in floral design or plant care, as it helps in managing and prolonging the life of floral arrangements effectively.