Carotenoids are important phytonutrients with antioxidant properties,and are widely used in foods and feedstuffs as Supplements.Astaxanthin,a red-colored ketocarotenoid,has strong antioxidant activity and thus can ben...Carotenoids are important phytonutrients with antioxidant properties,and are widely used in foods and feedstuffs as Supplements.Astaxanthin,a red-colored ketocarotenoid,has strong antioxidant activity and thus can benefit human health.However,astaxanthin is not produced in most higher plants.Here we report the bioengineering of astaxanthin biosynthesis in rice endosperm by introducing four synthetic genes,sZmPSY1,sPaCrtl,sCrBKT,and sHpBHY,which encode the enzymes phytoene synthase,phytoene desaturase,β-carotene ketolase,and β-carotene hydroxylase,respectively.Transgneic overexpression of two (sZmPSY1 and sPaCrtl),three (sZmPSY1,sPaCrtl and sCrBKT),and all these four genes driven by rice endosperm-specific promoters established the Carotenoid/ketocarotenoid/astaxanthin biosynthetic pathways in the endosperm and thus resulted in various types of germplasm,from the yellow-grained β-caro- tene-enriched Golden Rice to orange-red-grained Canthaxanthin Rice and Astaxanthin Rice,respectively. Grains Of Astaxanthin Rice were enriched with astaxanthin in the endosperm and had higher antioxidant activity.These results proved that introduction of a minimal set of four transgenes enables de novo biosynthesis of astaxanthin in therice endosperm.This work provides a Successful example for synthetic biology in plants and biofortification in crops;the biofortified rice products generated by this study could be consumed as health-promoting foods and processed tO produce dietary supplements.展开更多
基金The National Natural Science Foundation of China (317717,40)Guangdong Province Public Interest Research and Capacity Building Special Fund (2016A020210084+2 种基金2015B020201002)and the Ministry of Agriculture of China (2016ZX080100012016ZX08009002).
文摘Carotenoids are important phytonutrients with antioxidant properties,and are widely used in foods and feedstuffs as Supplements.Astaxanthin,a red-colored ketocarotenoid,has strong antioxidant activity and thus can benefit human health.However,astaxanthin is not produced in most higher plants.Here we report the bioengineering of astaxanthin biosynthesis in rice endosperm by introducing four synthetic genes,sZmPSY1,sPaCrtl,sCrBKT,and sHpBHY,which encode the enzymes phytoene synthase,phytoene desaturase,β-carotene ketolase,and β-carotene hydroxylase,respectively.Transgneic overexpression of two (sZmPSY1 and sPaCrtl),three (sZmPSY1,sPaCrtl and sCrBKT),and all these four genes driven by rice endosperm-specific promoters established the Carotenoid/ketocarotenoid/astaxanthin biosynthetic pathways in the endosperm and thus resulted in various types of germplasm,from the yellow-grained β-caro- tene-enriched Golden Rice to orange-red-grained Canthaxanthin Rice and Astaxanthin Rice,respectively. Grains Of Astaxanthin Rice were enriched with astaxanthin in the endosperm and had higher antioxidant activity.These results proved that introduction of a minimal set of four transgenes enables de novo biosynthesis of astaxanthin in therice endosperm.This work provides a Successful example for synthetic biology in plants and biofortification in crops;the biofortified rice products generated by this study could be consumed as health-promoting foods and processed tO produce dietary supplements.
