photosynthesis-destarching

the plant continuous to maintain its life by carrying out respiration to gain energy for metabolism in darkness.
the glucouse is one of the raw material for carrying out respiration.
so plants have to break down starch to glucose.
BUT why the starch will be used up?
Oh,its because it don't carry out photosynthesis without ,in turns no gluse and starch produced .this phenomenen is the same as people maintain his life without ingestion(photo.).we will use up protein(starch).
Then we are 'Deprotein'.