Most plants close their stomata at night. What color of light would be most effective in promoting stomatal opening in the middle of the night?
A) red
B) far-red
C) blue
D) red followed by far-red
E) far-red followed by blue

Question

Quizplus · Accepted Answer

Blue light is known to have a major role in stomatal opening, especially during the day. However, studies have shown that blue light can also promote stomatal opening during the night, when stomata are typically closed. This is because blue light can trigger the activation of potassium channels in guard cells, which leads to osmotic changes and ultimately stomatal opening. Therefore, of the given choices, blue light would be the most effective in promoting stomatal opening in the middle of the night.

Most Plants Close Their Stomata at Night