Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia off...Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia officinalis residues(MOR)as an example.The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients(magnolol and honokiol)originally remaining in MOR and to make MOR more accessible for hydrolysis.A metal–organic frame material MIL-101(Cr)with a maximum absorption capacity of 255.64 mg g^(-1)was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions,and 40 g L^(-1)reducing sugars were obtained with 81.8%enzymatic hydrolysis rate at 10%MOR solid loading.Finally,382 mg L-1β-amyrin was produced from MOR hydrolysates by an engineered yeast strain.In total,1 kg honokiol,8 kg magnolol,and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB.展开更多
As auxins are among the most important phytohormones,the regulation of auxin homeostasis is complex.Generally,auxin conjugates,especially IAA glucosides,are predominant at high auxin levels.Previous research on termin...As auxins are among the most important phytohormones,the regulation of auxin homeostasis is complex.Generally,auxin conjugates,especially IAA glucosides,are predominant at high auxin levels.Previous research on terminal glucosylation focused mainly on the O-position,while IAA-N-glucoside and IAA-Asp-N-glucoside have been neglected since their discovery in 2001.In our study,IAA-Asp-N-glucoside was found to be specifically abundant(as high as 4.13 mg/g)in the seeds of 58 ginkgo cultivars.Furthermore,a novel N-glucosyltransferase,termed GbNGT1,was identified via differential transcriptome analysis and in vitro enzymatic testing.It was found that GbNGT1 could catalyze IAA-Asp and IAA to form their corresponding N-glucosides.The enzyme was demonstrated to possess a specific catalytic capacity toward the N-position of the IAA-amino acid or IAA from 52 substrates.Docking and site-directed mutagenesis of this enzyme confirmed that the E15G mutant could almost completely abolish its N-glucosylation ability toward IAA-Asp and IAA in vitro and in vivo.The IAA modification of GbNGT1 and GbGH3.5 was verified by transient expression assay in Nicotiana benthamiana.The effect of GbNGT1 on IAA distribution promotes root growth in Arabidopsis thaliana.展开更多
基金supported by the National Key Research and Development Project(2019YFC1906601)China the Scientific and Technological Innovation Project of the Chinese Academy of Chinese Medical Sciences(C12021A04111)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZZ13-YQ-040).
文摘Herbal extraction residues(HERs)cause serious environmental pollution and resource waste.In this study,a novel green route was designed for the comprehensive reutilization of all components in HERs,taking Magnolia officinalis residues(MOR)as an example.The reluctant structure of MOR was first destroyed by alkali pretreatment to release the functional ingredients(magnolol and honokiol)originally remaining in MOR and to make MOR more accessible for hydrolysis.A metal–organic frame material MIL-101(Cr)with a maximum absorption capacity of 255.64 mg g^(-1)was synthesized to absorb the released honokiol and magnolol from the pretreated MOR solutions,and 40 g L^(-1)reducing sugars were obtained with 81.8%enzymatic hydrolysis rate at 10%MOR solid loading.Finally,382 mg L-1β-amyrin was produced from MOR hydrolysates by an engineered yeast strain.In total,1 kg honokiol,8 kg magnolol,and 7.64 kg β-amyrin could produce from 1 ton MOR by this cleaner process with a total economic output of 170,700 RMB.
基金This research was supported by Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CACMS Innovation Fund,C12021A04117)the National Key R&D Program of China(2019YFC1711100)Beijing Natural Science Foundation of China(7192138),and the Fundamental Research Funds for the Central Public Welfare Research Institute of China(ZZ13-YQ-097).
文摘As auxins are among the most important phytohormones,the regulation of auxin homeostasis is complex.Generally,auxin conjugates,especially IAA glucosides,are predominant at high auxin levels.Previous research on terminal glucosylation focused mainly on the O-position,while IAA-N-glucoside and IAA-Asp-N-glucoside have been neglected since their discovery in 2001.In our study,IAA-Asp-N-glucoside was found to be specifically abundant(as high as 4.13 mg/g)in the seeds of 58 ginkgo cultivars.Furthermore,a novel N-glucosyltransferase,termed GbNGT1,was identified via differential transcriptome analysis and in vitro enzymatic testing.It was found that GbNGT1 could catalyze IAA-Asp and IAA to form their corresponding N-glucosides.The enzyme was demonstrated to possess a specific catalytic capacity toward the N-position of the IAA-amino acid or IAA from 52 substrates.Docking and site-directed mutagenesis of this enzyme confirmed that the E15G mutant could almost completely abolish its N-glucosylation ability toward IAA-Asp and IAA in vitro and in vivo.The IAA modification of GbNGT1 and GbGH3.5 was verified by transient expression assay in Nicotiana benthamiana.The effect of GbNGT1 on IAA distribution promotes root growth in Arabidopsis thaliana.
