In leaves of C4 plants malic acid synthesis during CO2 fixation occurs in
- bundle sheath
- guard cells
- epidermal cells
- mesophyll cells
Answer
(4) mesophyll cells
Solution
As per NCERT, the primary CO2 acceptor in C4 plants is phosphoenol pyruvate (PEP), present in the mesophyll cells; the enzyme PEP carboxylase (PEPcase) is also present there.
⇒ PEP + CO2 oxaloacetic acid (OAA), a 4-carbon acid.
⇒ In the mesophyll cells OAA forms other 4-carbon acids such as malic acid or aspartic acid, which are then transported to the bundle sheath cells.
Answer: (4)