Aroma(volatile)compounds play important ecological functions in plants,and also contribute to the quality of plant-derived foods.Moreover,chiral aroma compounds affect their functions in plants and lead to different f...Aroma(volatile)compounds play important ecological functions in plants,and also contribute to the quality of plant-derived foods.Moreover,chiral aroma compounds affect their functions in plants and lead to different flavor quality properties.Formations of chiral aroma compounds are due to the presence of enzymes producing these compounds in plants,which are generally involved in the final biosynthetic step of the aroma compounds.Here,we review recent progress in research on the plant-derived enzymes producing chiral aroma compounds,and their changes in response to environmental factors.The chiral aroma enzymes that have been reported produce(R)-linalool,(S)-linalool,(R)-limonene,and(S)-limonene,etc.,and these enzymes are found in various plant species.We also discuss the origins of enantioselectivity in the plant-derived enzymes producing chiral aroma compounds and summarize the potential use of plants containing enzymes producing chiral aroma compounds for producing chiral flavors/fragrances.展开更多
Plant volatile compounds have important physiological and ecological functions.Phenylacetaldehyde(PAld),a volatile phenylpropanoid/benzenoid,accumulates in the leaves of tea(Camellia sinensis)plants grown under contin...Plant volatile compounds have important physiological and ecological functions.Phenylacetaldehyde(PAld),a volatile phenylpropanoid/benzenoid,accumulates in the leaves of tea(Camellia sinensis)plants grown under continuous shading.This study was conducted to determine whether PAld production is correlated with light and to elucidate the physiological functions of PAld in tea plants.Specifically,the upstream mechanism modulating PAld biosynthesis in tea plants under different light conditions as well as the effects of PAld on chloroplast/chlorophyll were investigated.The biosynthesis of PAld was inhibited under light,whereas it was induced in darkness.The structural gene encoding aromatic amino acid aminotransferase 1(CsAAAT1)was expressed at a high level in darkness,consistent with its importance for PAld accumulation.Additionally,the results of a transcriptional activation assay and an electrophoretic mobility shift assay indicated CsAAAT1 expression was slightly activated by phytochrome-interacting factor 3-2(CsPIF3-2),which is a light-responsive transcription factor.Furthermore,PAld might promote the excitation of chlorophyll in dark-treated chloroplasts and mediate electron energy transfer in cells.However,the accumulated PAld can degrade chloroplasts and chlorophyll,with potentially detrimental effects on photosynthesis.Moreover,PAld biosynthesis is inhibited in tea leaves by red and blue light,thereby decreasing the adverse effects of PAld on chloroplasts during daytime.In conclusion,the regulated biosynthesis of PAld in tea plants under light and in darkness leads to chloroplast modifications.The results of this study have expanded our understanding of the biosynthesis and functions of volatile phenylpropanoids/benzenoids in tea leaves.展开更多
Tea plants are subjected to multiple stresses during growth,development,and postharvest processing,which affects levels of secondary metabolites in leaves and influences tea functional properties and quality.Most stud...Tea plants are subjected to multiple stresses during growth,development,and postharvest processing,which affects levels of secondary metabolites in leaves and influences tea functional properties and quality.Most studies on secondary metabolism in tea have focused on gene,protein,and metabolite levels,whereas upstream regulatory mechanisms remain unclear.In this review,we exemplify DNA methylation and histone acetylation,summarize the important regulatory effects that epigenetic modifications have on plant secondary metabolism,and discuss feasible research strategies to elucidate the underlying specific epigenetic mechanisms of secondary metabolism regulation in tea.This information will help researchers investigate the epigenetic regulation of secondary metabolism in tea,providing key epigenetic data that can be used for future tea genetic breeding.展开更多
Aroma is an important quality-related trait of oolong tea.The compounds contributing to oolong tea aromas are mainly produced in response to stress during the enzyme-active stage of the tea manufacturing process.Epige...Aroma is an important quality-related trait of oolong tea.The compounds contributing to oolong tea aromas are mainly produced in response to stress during the enzyme-active stage of the tea manufacturing process.Epigenetic regulation affects stress-induced secondary metabolite production;however,the mechanisms regulating oolong tea aroma compound formation are unclear.In this study,the effect of histone acetylation on indole formation,an important aroma of oolong tea,was revealed and CsHDA8 was identified as a candidate regulator.Additionally,CsHDA8,which was localized in the nucleus and cytoplasm,may function as a histone deacetylase.Moreover,the binding of CsHDA8 to CsTSB2 promoter related to indole decreased during a wounding treatment,which resulted in increased histone acetylation and gene expression.The study results may clarify the regulatory effects of histone acetylation on the formation of tea secondary metabolites,with potential implications for studies on the epigenetic regulation in other non-model horticulture plants.展开更多
基金supported by the financial supports from the Guangdong Basic and Applied Basic Research Foundation(2020A1515010539)the Medical Science and Technology Research Foundation of Guangdong Province,China(A2019046)+1 种基金Guangdong Province Higher Vocational Colleges&Schools Pearl River Scholar(50117G25002)the Key Project of Universities in Guangdong Province(2021ZDZX4066).
文摘Aroma(volatile)compounds play important ecological functions in plants,and also contribute to the quality of plant-derived foods.Moreover,chiral aroma compounds affect their functions in plants and lead to different flavor quality properties.Formations of chiral aroma compounds are due to the presence of enzymes producing these compounds in plants,which are generally involved in the final biosynthetic step of the aroma compounds.Here,we review recent progress in research on the plant-derived enzymes producing chiral aroma compounds,and their changes in response to environmental factors.The chiral aroma enzymes that have been reported produce(R)-linalool,(S)-linalool,(R)-limonene,and(S)-limonene,etc.,and these enzymes are found in various plant species.We also discuss the origins of enantioselectivity in the plant-derived enzymes producing chiral aroma compounds and summarize the potential use of plants containing enzymes producing chiral aroma compounds for producing chiral flavors/fragrances.
基金supported by grants from the National Natural Science Foundation of China(31902074)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010539)+4 种基金the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2020QNRC001)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022351)the Basic Frontier Science Research Program of Chinese Academy of Sciences(ZDBS-LY-SM032)the Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams(2023KJ120)Guangdong Provincial Department of Science and Technology Rural Science and Technology Commissioner Project(KTP20210351).
文摘Plant volatile compounds have important physiological and ecological functions.Phenylacetaldehyde(PAld),a volatile phenylpropanoid/benzenoid,accumulates in the leaves of tea(Camellia sinensis)plants grown under continuous shading.This study was conducted to determine whether PAld production is correlated with light and to elucidate the physiological functions of PAld in tea plants.Specifically,the upstream mechanism modulating PAld biosynthesis in tea plants under different light conditions as well as the effects of PAld on chloroplast/chlorophyll were investigated.The biosynthesis of PAld was inhibited under light,whereas it was induced in darkness.The structural gene encoding aromatic amino acid aminotransferase 1(CsAAAT1)was expressed at a high level in darkness,consistent with its importance for PAld accumulation.Additionally,the results of a transcriptional activation assay and an electrophoretic mobility shift assay indicated CsAAAT1 expression was slightly activated by phytochrome-interacting factor 3-2(CsPIF3-2),which is a light-responsive transcription factor.Furthermore,PAld might promote the excitation of chlorophyll in dark-treated chloroplasts and mediate electron energy transfer in cells.However,the accumulated PAld can degrade chloroplasts and chlorophyll,with potentially detrimental effects on photosynthesis.Moreover,PAld biosynthesis is inhibited in tea leaves by red and blue light,thereby decreasing the adverse effects of PAld on chloroplasts during daytime.In conclusion,the regulated biosynthesis of PAld in tea plants under light and in darkness leads to chloroplast modifications.The results of this study have expanded our understanding of the biosynthesis and functions of volatile phenylpropanoids/benzenoids in tea leaves.
基金Some of the research performed by the authors is supported by financial support from the National Natural Science Foundation of China(31870684,31902073,and 31922077)the Basic Frontier Science Research Program of the Chinese Academy of Sciences(ZDBS-LY-SM032)+4 种基金the Guangdong Basic and Applied Basic Research Foundation(2020A1515010007)the Regional Key Project of Science and Technology Service Network Plan of Chinese Academy of Sciences(KFJ-STS-QYZX-093)the National Key Research and Development Program of China(2018YFD1000601)the Hangzhou Qianjiang Special Experts Project,the Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams(2020KJ120)the Foundation of Science and Technology Program of Guangzhou(201804010097).
文摘Tea plants are subjected to multiple stresses during growth,development,and postharvest processing,which affects levels of secondary metabolites in leaves and influences tea functional properties and quality.Most studies on secondary metabolism in tea have focused on gene,protein,and metabolite levels,whereas upstream regulatory mechanisms remain unclear.In this review,we exemplify DNA methylation and histone acetylation,summarize the important regulatory effects that epigenetic modifications have on plant secondary metabolism,and discuss feasible research strategies to elucidate the underlying specific epigenetic mechanisms of secondary metabolism regulation in tea.This information will help researchers investigate the epigenetic regulation of secondary metabolism in tea,providing key epigenetic data that can be used for future tea genetic breeding.
基金the financial support from the National Natural Science Foundation of China(31870684)the Foundation of Science and Technology Program of Guangzhou(202102020806)+2 种基金the Key Project of Universities in Guangdong Province(2021ZDZX4066)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2020QNRC001)the Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams(2022KJ120).
文摘Aroma is an important quality-related trait of oolong tea.The compounds contributing to oolong tea aromas are mainly produced in response to stress during the enzyme-active stage of the tea manufacturing process.Epigenetic regulation affects stress-induced secondary metabolite production;however,the mechanisms regulating oolong tea aroma compound formation are unclear.In this study,the effect of histone acetylation on indole formation,an important aroma of oolong tea,was revealed and CsHDA8 was identified as a candidate regulator.Additionally,CsHDA8,which was localized in the nucleus and cytoplasm,may function as a histone deacetylase.Moreover,the binding of CsHDA8 to CsTSB2 promoter related to indole decreased during a wounding treatment,which resulted in increased histone acetylation and gene expression.The study results may clarify the regulatory effects of histone acetylation on the formation of tea secondary metabolites,with potential implications for studies on the epigenetic regulation in other non-model horticulture plants.
