摘要：Restricted genetic diversity can supply only a limited number of elite genes for modern plant cultivation and *** this study,we demonstrate that rational design enables the engineering of geranyl-geranyl diphosphate synthase(NtGGPPS),an enzyme of the methylerythritol phosphate pathway(MEP)in the model plant Nicotiana *** the crucial bottleneck in carotenoid biosynthesis,NtGGPPS1 interacts with phytoene synthase(NtPSY1)to channel GGPP into the production of *** of this enzyme in the ntggpps1 mutant leads to decreased carotenoid *** the aim of enhanc-ing NtGGPPS1 activity,we undertook structure-guided rational redesign of its substrate binding pocket in combination with sequence *** activity of the designed NtGGPPS1(a pentuple mutant of five sites V154A/I161L/F218Y/I209S/V233E,d-NtGGPPS1)was measured by a high-throughput colorimetric assay.d-NtGGPPS1 exhibited significantly higher conversion of IPP and each co-substrate(DMAPP~1995.5-fold,GPP~25.9-fold,and FPP~16.7-fold)for GGPP synthesis compared with wild-type ***,the transient and stable expression of d-NtGGPPS1 in the ntggpps1 mutant increased carotenoid levels in leaves,improved photosynthetic efficiency,and increased biomass relative to *** findings provide a firm basis for the engineering of GGPPS and will facilitate the development of quality and yield *** results open the door for the structure-guided rational design of elite genes in higher plants。

摘要：Microbial synthesis of carotenoids is a highly desirable alternative to plant extraction and chemical *** this study,we investigated multidimensional strategies to improve the carotenoid synthesis in the industrial workhorse of Saccharomyces ***,we rewired the yeast central metabolism by optimizing non-oxidative glycolysis pathway for an improved acetyl-CoA ***,we restricted the consumption of farnesyl pyrophosphate(FPP)by the down-regulation of squalene synthase using the PEST ***,we further explored the human lipid binding/transfer protein saposin B(hSapB)-mediated metabolic sink for an enhanced storage of lipophilic ***,the copper-induced GAL expression system was engineered to function in the yeast-peptone-dextrose medium for an increased biomass *** combining the abovementioned strategies,the final engineered yeast produced 166.79±10.43 mg/Ⅰβ-carotene in shake flasks,which was nearly 5-fold improvement of the parental carotenoid-producing ***,we envision that multidimensional strategies reported here might be applicable to other hosts for the future industrial development of carotenoid synthesis from renewable feedstocks.