Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributi...Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality.However,the details of their biosynthesis and metabolism in tea plants are still unknown.Here,eugenol glucoside was unambiguously identified as a native metabolite in the tea plant,and its biosynthesis was shown to be induced by low temperature treatment.Through the analysis of UGTs induced by low temperature,the glycosyltransferase CsUGT78A15 was identified in tea,and its encoded protein was shown to catalyze the glucosylation of eugenol.Vmax/Km ratios showed that eugenol was the most suitable substrate for CsUGT78A15.Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose,followed by galactose and glucuronic acid.The expression of CsUGT78A15was correlatedwith the accumulation of eugenol glucoside in different tissues and genotypes of tea.Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress,indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress.The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside.展开更多
The Darboux transformation for the two dimensional A_(2n-1)^((2))Toda equations is constructed so that it preserves all the symmetries of the corresponding Lax pair.The expression of exact solutions of the equation is...The Darboux transformation for the two dimensional A_(2n-1)^((2))Toda equations is constructed so that it preserves all the symmetries of the corresponding Lax pair.The expression of exact solutions of the equation is obtained by using Darboux transformation.展开更多
Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based ...Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings(both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm^(–2)·a^(–1), and the average annual payment increased to 1146 CNY·hm^(–2) at a medium carbon price of 50 CNY·Mg^(–1) CO_2^(–e). Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market.Overall, however, less carbon is sequestered by ecological plantings(i.e., mixed native trees and shrubs) compared to agriculture.展开更多
基金the Science Fund for the National Natural Science Foundation of China(Grant Nos.31961133030,31870678)the National Key Research and Development Program of China(Grant No.2018YFD1000601)+1 种基金Distinguished Young Scientists of Anhui Province(Grant No.1908085J12)the Graduate Innovation Fund(Grant No.2020ysj-32).
文摘Eugenol is a natural phenolic compound known for its health-promoting properties and its ability to add a floral scent to tea plants.Plant eugenol glycosides have been identified and shown to make important contributions to fruit floral quality.However,the details of their biosynthesis and metabolism in tea plants are still unknown.Here,eugenol glucoside was unambiguously identified as a native metabolite in the tea plant,and its biosynthesis was shown to be induced by low temperature treatment.Through the analysis of UGTs induced by low temperature,the glycosyltransferase CsUGT78A15 was identified in tea,and its encoded protein was shown to catalyze the glucosylation of eugenol.Vmax/Km ratios showed that eugenol was the most suitable substrate for CsUGT78A15.Sugar donor preference analysis showed that CsUGT78A15 had a higher selectivity for glucose,followed by galactose and glucuronic acid.The expression of CsUGT78A15was correlatedwith the accumulation of eugenol glucoside in different tissues and genotypes of tea.Down-regulation of CsUGT78A15 led to a decreased eugenol glucoside content under cold stress,indicating that CsUGT78A15 plays an important role in the biosynthesis of eugenol glucoside under cold stress.The identification of eugenol glucoside in the tea plant and the discovery of a cold stress-induced eugenol glucosyltransferase in tea provide the foundation for the improvement of tea flavor under cold stress and the biotechnological production of eugenol glucoside.
基金supported by the National Natural Science Foundation of China(No.11971114)the Key Laboratory of Mathematics for Nonlinear Sciences of Ministry of Education of China。
文摘The Darboux transformation for the two dimensional A_(2n-1)^((2))Toda equations is constructed so that it preserves all the symmetries of the corresponding Lax pair.The expression of exact solutions of the equation is obtained by using Darboux transformation.
基金supported by the National Natural Science Foundation of China (41371020)Fundamental Research Funds for the Central Universities (GK201502010)+2 种基金China Postdoctoral Science Foundation on the 58th Group (2015M582706)Postdoctoral Scientific Research Project Foundation of Shaanxi Province in 2015China 111 Project (B12007)
文摘Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings(both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm^(–2)·a^(–1), and the average annual payment increased to 1146 CNY·hm^(–2) at a medium carbon price of 50 CNY·Mg^(–1) CO_2^(–e). Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market.Overall, however, less carbon is sequestered by ecological plantings(i.e., mixed native trees and shrubs) compared to agriculture.
