Question

$C_4$ plant are less efficient at low temperature due to

• A. Low $O_2$ affinity of PEP case
• B. Cold sensitivity of PEP carboxylase enzyme
• C. Reduced rate of decarboxylation of organic acids
• D. High energy requirement for $C{O}_2$ fixation.

Answer 1

The correct option is B Cold sensitivity of PEP carboxylase enzyme

C${}_4$ plants are widespread in tropical regions as they have ability to use the maximum carbon dioxide even with the high temperature and high light intensity. However, their photosynthetic efficiency declines at low temperature due to inactivation of the PEP carboxylase enzyme and high amount of energy required due to photoprotection effect.

Hence, the correct answer is 'Cold Sensitivity of PEP carboxylase enzyme'