TLS Online TPP Program

#Question id: 10492


Three major distinct metabolic pathways that can supply osmotically active solutes to guard cells have been clearly characterized,

#Unit 6. System Physiology – Plant
  1. The uptake of K+ and Cl– from the apoplast, coupled to the biosynthesis of malate2– within the guard cells

  2. The production of sucrose in the guard cell cytoplasm from precursors originating from starch hydrolysis in the guard cell chloroplast

  3. The changes in osmotic potential required for stomatal opening in the morning are mediated by sucrose, whereas the afternoon changes are mediated by potassium and its counterions

  4. The production of sucrose from precursors made in the photosynthetic carbon fixation pathway at the guard cell chloroplast