Question

Many tropical plants grown in temperate gardens are vulnerable to winter temperatures even above the freezing point of water. Why might such a plant experience stress/tissue damage at cool, non-freezing temperatures?

a) Lack of sunlight
b) Inefficient photosynthesis
c) Disruption of water transport
d) Excessive heat absorption

Answer 1

Tropical plants in temperate gardens may suffer damage at cool temperatures due to a disruption of water transport, cavitation in the xylem, and ongoing water loss through transpiration, compounded by pest infestations.

Step-by-step explanation:

Many tropical plants grown in temperate gardens may experience stress or tissue damage at cool, non-freezing temperatures due to a disruption of water transport. Water cannot flow in the xylem if it begins to freeze. Even before the freezing point, the chill can lead to cavitation (air locking) of vessels and tracheids, disrupting xylem water transport. Furthermore, as temperatures cool, the physical processes within a plant slow down, which affects the efficiency of water uptake and can lead to desiccation due to continual water loss through transpiration. Other stress factors include an increased risk of plant death due to shorter, milder winters that fail to suppress pests, leading to infestations that further stress the plant. As a result, tissues may experience damage that can impact a plant's health and productivity.