Transport in Plants Question 50

50. Conversion of starch to organic acids is required for

[1992]

(a) stomatal opening

(b) stomatal closing

(c) stomatal formation

(d) stomatal activity

Show Answer

Answer : a

Hints & Solutions

(a) Starch is converted to malic acid (organic acid) through the action of an enzyme phosphoenol pyruvate carboxylase (PEPC) under condition of high $pH$ when most of the $CO_2$ is utilized due to high photosynthetic rate during daytime.