Putative Possesses Lycopene β-Cyclase Activity, Boosts Carotenoid Levels, and Increases Salt Tolerance in Heterologous Plants.

Plant carotenoids are synthesized and accumulated in plastids through a highly regulated pathway. Lycopene β-cyclase (LCYB) is a key enzyme involved directly in the synthesis of α-carotene and β-carotene through the cyclization of trans-lycopene. harbors two genes, of which (annotated as ) is mostly expressed in mature storage roots, an organ that accumulates high α-carotene and β-carotene content. In this work, we determined that of the orange Nantes variety presents plastid localization and encodes for a functional LCYB enzyme determined by means of heterologous complementation in . Also, ectopic expression of in tobacco () and kiwi () plants increases total carotenoid content showing its functional role in plants. In addition, transgenic tobacco T2 homozygous plants showed better performance under chronic salt treatment, while kiwi transgenic calli also presented a higher survival rate under salt treatments than control calli. Our results allow us to propose as a prime candidate to engineer carotenoid biofortified crops as well as crops resilient to saline environments.