Red clover (Trifolium pratense L.) is a legume forage abundant in phenolic compounds. It tends to brown when cut for hay, due to oxidation of phenolic compounds catalyzed by polyphenol oxidase (PPO), and subsequent bi...Red clover (Trifolium pratense L.) is a legume forage abundant in phenolic compounds. It tends to brown when cut for hay, due to oxidation of phenolic compounds catalyzed by polyphenol oxidase (PPO), and subsequent binding to proteins. Selecting for a greener hay may provide information about the relationship of browning, PPO, and phenolics to each other. The red clover Kenland cultivar was selected over eight breeding cycles for decreased browning after being cut and dried 48 h in the field. Expression of PPO1 and PPO3, in Kenland and three of the eight cycles, was compared by real-time quantitative PCR. Phenolic compounds in Kenland and Cycle 8, collected 0, 24, and 48 h after cutting, were quantified by high-performance liquid chromatography (HPLC). Visual browning scores decreased 12% between Kenland and Cycle 8 (P = 0.02). PPO1 and PPO3 gene expression were not affected by selection. Clovamide decreased 26% in Cycle 8 relative to Kenland (P = 0.016). Sissotrin decreased 10% in Cycle 8 (P = 0.043). Neither total formononetin nor total biochanin A was affected by selection (P = 0.63 and 0.45, respectively). These results suggest that when selecting clover for decreased postharvest browning, a decrease occurs in a phenolic compound that can bind protein independently of PPO. However, PPO1 and PPO3 gene expression, and the major red clover isoflavones, are minimally affected.展开更多
Objective:Trifolium pratense has many healing properties,including fewer complications of menopause,cancer cell suppression,reducing blood glucose and lipids,as well as cardiovascular beneficial effects.The purpose of...Objective:Trifolium pratense has many healing properties,including fewer complications of menopause,cancer cell suppression,reducing blood glucose and lipids,as well as cardiovascular beneficial effects.The purpose of this study was to identify the phytochemical and mineral composition of T.pratense.Methods:Plant aerial parts were harvested and dried,and then hydroalcoholic and alcoholic extracts were prepared.Gas chromatography-mass spectrometry(GC-MS)analytical method was used to identify volatile compounds then liquid chromatography-electrospray ionization mass spectrometry(LC-ESI-MS)was used to identify polyphenols and the mineral elements were identify by inductively coupled plasma atomic emission spectrometer/ICP-AES and scanning electron microscope-energy-dispersive X-ray spectroscopy(SEM-EDS)methods.Total phenolic content(TPC)was determined based on colorimetric method,and total flavonoid content(TFC)was established based on the folin-chiocalteau reagent.Furthermore,two assays(DPPH and FRAP)were used to measure the antioxidant capacity of T.pratense ethanolic extract.Results:A total of 37 polyphenols and 107 peaks were identified by LC-ESI-MS analysis,and the GC/MS method also detected 21 volatile compounds,the most important of which were methylcyclopentane,dimethylpentanal and hexadecanol.A total of 18 mineral elements,including K,Mg,Al,Si,Zn,Ni,Cu,Se,Co,Fe,Mn,and Ca in the plant,were identified ICP-AES and SEM-EDS analysis.Conclusion:T.pratense has many therapeutic compounds such as polyphenol(isoflavone and flavonoids),volatile compounds,and essential mineral elements,which can be formulated purely and used in the pharmaceutical and traditional medicine industries.展开更多
Background:Winter climate change including frequent freeze-thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops.Non-bloating perennial forage legume species including ...Background:Winter climate change including frequent freeze-thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops.Non-bloating perennial forage legume species including sainfoin,birdsfoot trefoil,red clover,and alsike clover have been bred for their adaptation to harsh winter conditions.In parallel,the selection of cold-tolerant rhizobial strains could allow earlier symbiotic nitrogen(N)fixation to hasten spring regrowth of legumes.Methods:To identify strains forming nodules rapidly and showing high N-fixing potential,60 rhizobial strains in association with four temperate legume species were evaluated over 11 weeks under spring soil temperatures for kinetics of nodule formation,nitrogenase activity,and host yield.Results:Strains differed in their capacity to form efficient nodules on legume hosts over time.Strains showing higher nitrogenase activity were arctic strain N10 with sainfoin and strain L2 with birdsfoot trefoil.For clovers,nitrogenase activity was similar for control and inoculated plants,likely due to formation of effective nodules in controls by endophyte rhizobia present in seeds.Conclusions:Selection based on nodulation kinetics at low temperature,nitrogenase activity,and yield was effective to identify performant rhizobial strains for legume crops.The use of cold-tolerant strains could help mitigate winter climatic changes.展开更多
文摘Red clover (Trifolium pratense L.) is a legume forage abundant in phenolic compounds. It tends to brown when cut for hay, due to oxidation of phenolic compounds catalyzed by polyphenol oxidase (PPO), and subsequent binding to proteins. Selecting for a greener hay may provide information about the relationship of browning, PPO, and phenolics to each other. The red clover Kenland cultivar was selected over eight breeding cycles for decreased browning after being cut and dried 48 h in the field. Expression of PPO1 and PPO3, in Kenland and three of the eight cycles, was compared by real-time quantitative PCR. Phenolic compounds in Kenland and Cycle 8, collected 0, 24, and 48 h after cutting, were quantified by high-performance liquid chromatography (HPLC). Visual browning scores decreased 12% between Kenland and Cycle 8 (P = 0.02). PPO1 and PPO3 gene expression were not affected by selection. Clovamide decreased 26% in Cycle 8 relative to Kenland (P = 0.016). Sissotrin decreased 10% in Cycle 8 (P = 0.043). Neither total formononetin nor total biochanin A was affected by selection (P = 0.63 and 0.45, respectively). These results suggest that when selecting clover for decreased postharvest browning, a decrease occurs in a phenolic compound that can bind protein independently of PPO. However, PPO1 and PPO3 gene expression, and the major red clover isoflavones, are minimally affected.
基金This work was supported by the Kermanshah University of Medical Science(grant number:980292)for Ph.D.thesis.
文摘Objective:Trifolium pratense has many healing properties,including fewer complications of menopause,cancer cell suppression,reducing blood glucose and lipids,as well as cardiovascular beneficial effects.The purpose of this study was to identify the phytochemical and mineral composition of T.pratense.Methods:Plant aerial parts were harvested and dried,and then hydroalcoholic and alcoholic extracts were prepared.Gas chromatography-mass spectrometry(GC-MS)analytical method was used to identify volatile compounds then liquid chromatography-electrospray ionization mass spectrometry(LC-ESI-MS)was used to identify polyphenols and the mineral elements were identify by inductively coupled plasma atomic emission spectrometer/ICP-AES and scanning electron microscope-energy-dispersive X-ray spectroscopy(SEM-EDS)methods.Total phenolic content(TPC)was determined based on colorimetric method,and total flavonoid content(TFC)was established based on the folin-chiocalteau reagent.Furthermore,two assays(DPPH and FRAP)were used to measure the antioxidant capacity of T.pratense ethanolic extract.Results:A total of 37 polyphenols and 107 peaks were identified by LC-ESI-MS analysis,and the GC/MS method also detected 21 volatile compounds,the most important of which were methylcyclopentane,dimethylpentanal and hexadecanol.A total of 18 mineral elements,including K,Mg,Al,Si,Zn,Ni,Cu,Se,Co,Fe,Mn,and Ca in the plant,were identified ICP-AES and SEM-EDS analysis.Conclusion:T.pratense has many therapeutic compounds such as polyphenol(isoflavone and flavonoids),volatile compounds,and essential mineral elements,which can be formulated purely and used in the pharmaceutical and traditional medicine industries.
文摘Background:Winter climate change including frequent freeze-thaw episodes and shallow snow cover will have major impacts on the spring regrowth of perennial crops.Non-bloating perennial forage legume species including sainfoin,birdsfoot trefoil,red clover,and alsike clover have been bred for their adaptation to harsh winter conditions.In parallel,the selection of cold-tolerant rhizobial strains could allow earlier symbiotic nitrogen(N)fixation to hasten spring regrowth of legumes.Methods:To identify strains forming nodules rapidly and showing high N-fixing potential,60 rhizobial strains in association with four temperate legume species were evaluated over 11 weeks under spring soil temperatures for kinetics of nodule formation,nitrogenase activity,and host yield.Results:Strains differed in their capacity to form efficient nodules on legume hosts over time.Strains showing higher nitrogenase activity were arctic strain N10 with sainfoin and strain L2 with birdsfoot trefoil.For clovers,nitrogenase activity was similar for control and inoculated plants,likely due to formation of effective nodules in controls by endophyte rhizobia present in seeds.Conclusions:Selection based on nodulation kinetics at low temperature,nitrogenase activity,and yield was effective to identify performant rhizobial strains for legume crops.The use of cold-tolerant strains could help mitigate winter climatic changes.
