Thank you for reporting, we will resolve it shortly
Q.
Opening and closing of stomata is due to the :-
AIPMTAIPMT 2002Transport in Plants
Solution:
During night or dark : CO2 conc. increases in sub-stomatal cavities ---> ABA participation --> K+ ions exchange stopped --> K+ ions transported back into subsidiary cells --> Decreased pH -->Starch synthesized in guard cells --> Decreased O.P of guard cells -->Exosmosis from guard cell --> Stomata close