Inducible expression systems such as theoriboswitches and pentatricopeptide repeat proteins have been widely studied in an effort to control and modulate expression of transgene products in transplastomic plants.[13] One big advantage in using inducible expression systems is to optimize concentration of transgene protein production.[13] For example, young plants need to devote energy and resources into growth and development to become mature plants.[13] Constitutive expression of the transgene would therefore be detrimental for plant growth and development, as it takes away valuable energy and resources to express the foreign gene construct instead.[13] This would result in a poorly developed transplastomic plant with low product yield.[13] Inducible expression expression of the transgene would overcome this limitation and allow the plant to mature fully like a normal wildtype plant before it is induced chemically to begin production of the transgene which can then be harvested.[13]