Plants can only display traits that already exist in their DNA so if that trait did not yet exist in the plants DNA, you would need a mutation. Positive mutations are very rare, so maybe you could have intense light on a select group of plants, breed them, find which offspring absorb the light the best, then continue breeding them and pray you get the proper mutations that would allow massive efficiency. This is not natural though, if you are speaking of creating natural plants that help end world hunger, we need to focus on mass production of alkaline plants that Dr Sebi discussed.
