No,When we consider any plant, it takes O2 and releases CO2 during day. It is due to respiration which gives the plant energy as it does to humans and other organisms.But photosynthesis is a complete opposite reaction where CO2 is taken in and O2 is given out. This is for plants to prepare its own food.During day, both of these reaction occur but respiration is considerably less when compared to photosynthesis. So most of them get the wrong notion that plants only take in CO2 and give out O2 in morning.But during night as only respiration takes place (since plants require sunlight for photosynthesis). Hence plants breathe as any other creature.