Answer:
Chloroplast
Step-by-step explanation:
This is because in the first stage of photosynthesis(light dependent stage) i water molecules is spilt by sunlight absorbed by chlorophyll- Photolysis into H+ and electrons, with Oxygen.
It is the H+ from above that is used to reduce CO2 in the light independent stage, as the Calvin Cycle, to produce Glucose, fatty acid, and protein.
Therefore in absence of water, absorption by the xylem due to inhibition by toxin, Photosynthesis is INHIBITED.Since no H+ is produced.