People mistakenly believe that plants feed on water, oxygen and sunlight. That is not true. Plants, like almost all other living being, uses ATP to power its cells. The difference from plants to other living creatures is how they convert their ADP to ATP. Like most other living creatures, they use glycose for that. Plants have mitochondria just like most living creatures — and mitochondria power their cells. What plants do that other creatures don’t, however, is to convert carbon dioxide and water into glycose!
So the thing is, plant food is glycose, just like for nearly all other living creatures. And they produce that glycose by themselves, through photosynthesis. The raw materials for that are obtained from the atmosphere, soil and using sunlight to power it all up.
Plants make their food by a process called Photosynthesis. Plants convert carbondioxide and water into energy (food) in the presence of sunlight, hence the name Photosynthesis (in Greek photo- "light", and, synthesis- "putting together). If you wonder where does this process takes place in the plant, the answer is in the leaves. The plant leaf cells are abundant with the organelle chlorophyll which contains the green pigment that absorbs the sunlight rapidly facilitating Photosynthesis; also gives green colour to the plant.
Some plants can survive in very low-light conditions. If you think about dark, rainforest canopies, there are plants that grow in that environment. They have evolutionary adaptations to handle these low-light environments, which include making broad, thin leaves to capture as much sunlight as they can.
But basically if a plant is green, it needs sunlight at some point to grow. Otherwise, it can’t survive.
Source: Rekha M, Scientist at Bioscience Research Foundation (2017-present)