Overexpression of golgi protein CYP21-4s improves crop productivity in potato and rice by increasing the abundance of mannosidic glycoproteins

Abstract

CYP21-4 is a novel Golgi-localized cyclophilin protein involved in oxidative stress tolerance.Here, we generated transgenic plants overexpressing AtCYP21-4 and OsCYP21-4 in potato and rice, respectively.The stems and roots of AtCYP21-4-overexpressing potato plants were longer than those of wild-type (WT)plants, which resulted in heavier tubers.In vitro tuberization in the transgenic potato also resulted in significantly greater tuber number and weight, as well as a shorter time to microtuber formation.Similarly, OsCYP21-4-overexpressing transgenic rice plants had higher biomass and productivity with longer early-stage internodes than the WT and higher seed weight.Immunoblot analysis with CYP21-4 antibody showed that these productivity-enhancing phenotypes were associated with high CYP21-4s protein expression.Anatomically, transgenic potato stems exhibited higher lignin content in xylem cells and thicker leaves.In addition, relative content of mannosidic glycoproteins per unit of total protein was above 20% in transgenic potato tubers and rice grains.Based on these findings, we propose that CYP21-4s are involved in the growth and development of plant vegetative and storage tissues via their effects on glycoprotein abundance or glycan processing in the Golgi apparatus.Thus, increasing CYP21-4s expression in crops could represent an alternative way to increase crop productivity and yield.