The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 culti...The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.展开更多
Geraniol is an important contributor to the pleasant floral scent of tea products and one of the most abundant aroma compounds in tea plants;however,its biosynthesis and physiological function in response to stress in...Geraniol is an important contributor to the pleasant floral scent of tea products and one of the most abundant aroma compounds in tea plants;however,its biosynthesis and physiological function in response to stress in tea plants remain unclear.The proteins encoded by the full-length terpene synthase(CsTPS1)and its alternative splicing isoform(CsTPS1-AS)could catalyze the formation of geraniol when GPP was used as a substrate in vitro,whereas the expression of CsTPS1-AS was only significantly induced by Colletotrichum gloeosporioides and Neopestalotiopsis sp.infection.Silencing of CsTPS1 and CsTPS1-AS resulted in a significant decrease of geraniol content in tea plants.The geraniol content and disease resistance of tea plants were compared when CsTPS1 and CsTPS1-AS were silenced.Down-regulation of the expression of CsTPS1-AS reduced the accumulation of geraniol,and the silenced tea plants exhibited greater susceptibility to pathogen infection than control plants.However,there was no significant difference observed in the geraniol content and pathogen resistance between CsTPS1-silenced plants and control plants in the tea plants infected with two pathogens.Further analysis showed that silencing of CsTPS1-AS led to a decrease in the expression of the defense-related genes PR1 and PR2 and SA pathway-related genes in tea plants,which increased the susceptibility of tea plants to pathogens infections.Both in vitro and in vivo results indicated that CsTPS1 is involved in the regulation of geraniol formation and plant defense via alternative splicing in tea plants.The results of this study provide new insights into geraniol biosynthesis and highlight the role of monoterpene synthases in modulating plant disease resistance via alternative splicing.展开更多
Plants respond to environmental stimuli via the release of volatile organic compounds(VOCs),and neighboring plants constantly monitor and respond to these VOCs with great sensitivity and discrimination.This sensing ca...Plants respond to environmental stimuli via the release of volatile organic compounds(VOCs),and neighboring plants constantly monitor and respond to these VOCs with great sensitivity and discrimination.This sensing can trigger increased plant fitness and reduce future plant damage through the priming of their own defenses.The defense mechanism in neighboring plants can either be induced by activation of the regulatory or transcriptional machinery,or it can be delayed by the absorption and storage of VOCs for the generation of an appropriate response later.Despite much research,many key questions remain on the role of VOCs in interplant communication and plant fitness.Here we review recent research on the VOCs induced by biotic(i.e.insects and pathogens)and abiotic(i.e.cold,drought,and salt)stresses,and elucidate the biosynthesis of stress-induced VOCs in tea plants.Our focus is on the role of stress-induced VOCs in complex ecological environments.Particularly,the roles of VOCs under abiotic stress are highlighted.Finally,we discuss pertinent questions and future research directions for advancing our understanding of plant interactions via VOCs.展开更多
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
Plants have developed sophisticated mechanisms to survive in dynamic environments.Plants can communicate via volatile organic compounds(VOCs)to warn neighboring plants of threats.In most cases,VOCs act as positive reg...Plants have developed sophisticated mechanisms to survive in dynamic environments.Plants can communicate via volatile organic compounds(VOCs)to warn neighboring plants of threats.In most cases,VOCs act as positive regulators of plant defense.However,the communication and role of volatiles in response to drought stress are poorly understood.Here,we showed that tea plants release numerous VOCs.Among them,methyl salicylate(MeSA),benzyl alcohol,and phenethyl alcohol markedly increased under drought stress.Interestingly,further experiments revealed that drought-induced MeSA lowered the abscisic acid(ABA)content in neighboring plants by reducing 9-cis-epoxycarotenoid dioxygenase(NCED)gene expression,resulting in inhibition of stomatal closure and ultimately decreasing early drought tolerance in neighboring plants.Exogenous application of ABA reduced the wilting of tea plants caused by MeSA exposure.Exposure of Nicotiana benthamiana to MeSA also led to severe wilting,indicating that the ability of drought-induced MeSA to reduce early drought tolerance in neighboring plants may be conserved in other plant species.Taken together,these results provide evidence that drought-induced volatiles can reduce early drought tolerance in neighboring plants and lay a novel theoretical foundation for optimizing plant density and spacing.展开更多
After the publication of this article 1,the authors became aware that the word of“tea”was not mentioned in the title.To make the title clear and complete,the word‘tea’is added to the title.
Plants have evolved sophisticated defense mechanisms to overcome their sessile nature.However,if and how volatiles from cold‐stressed plants can trigger interplant communication is still unknown.Here,we provide the f...Plants have evolved sophisticated defense mechanisms to overcome their sessile nature.However,if and how volatiles from cold‐stressed plants can trigger interplant communication is still unknown.Here,we provide the first evidence for interplant communication via inducible volatiles in cold stress.The volatiles,including nerolidol,geraniol,linalool,and methyl salicylate,emitted from cold‐stressed tea plants play key role(s)in priming cold tolerance of their neighbors via a C‐repeatbinding factors‐dependent pathway.The knowledge will help us to understand how plants respond to volatile cues in cold stress and agricultural ecosystems.展开更多
Background and Aims:Acute-on-chronic liver failure(ACLF)is associated with very high mortality.Accurate prediction of prognosis is critical in navigating optimal treatment decisions to improve patient survival.This st...Background and Aims:Acute-on-chronic liver failure(ACLF)is associated with very high mortality.Accurate prediction of prognosis is critical in navigating optimal treatment decisions to improve patient survival.This study was aimed to develop a new nomogram integrating two-dimensional shear wave elastography(2D-SWE)values with other independent prognostic factors to improve the precision of predicting ACLF patient outcomes.Methods:A total of 449 consecutive patients with ACLF were recruited and randomly allocated to a training cohort(n=315)or a test cohort(n=134).2D-SWE values,conventional ultrasound features,laboratory tests,and other clinical characteristics were included in univariate and multivariate analysis.Factors with prognostic value were then used to construct a novel prognostic nomogram.Receiver operating curves(ROCs)were generated to evaluate and compare the performance of the novel and published models including the Model for EndStage Liver Disease(MELD),MELD combined with sodium(MELD-Na),and Jin’s model.The model was validated in a prospective cohort(n=102).Results:A ACLF prognostic nomogram was developed with independent prognostic factors,including 2D-SWE,age,total bilirubin(TB),neutrophils(Neu),and the international normalized ratio(INR).The area under the ROC curve(AUC)was 0.849 for the new model in the training cohort and 0.861 in the prospective validation cohort,which were significantly greater than those for MELD(0.758),MELD-Na(0.750),and Jin’s model(0.777,all p<0.05).Calibration curve analysis revealed good agreement between the predicted and observed probabilities.The new nomogram had superior overall net benefit and clinical utility.Conclusions:We established and validated a 2D-SWE-based noninvasive nomogram to predict the prognosis of ACLF patients that was more accurate than other prognostic models.展开更多
基金financially supported by National Natural Science Foundation of China(Grant Nos.31961133030,31870678,32022076)Science Fund for Distinguished Young Scientists of Anhui Province(Grant No.1908085J12).
文摘The carotenoid-derived volatileβ-ionone makes an important contribution to tea fragrance.Here,we qualitatively and quantitatively analysed 15 carotenoids in tea leaves of 13 cultivars by UHPLC-APCI-MS/MS.The 13 cultivars were divided into two groups by PCA(Principal Component Analysis)clustering analysis of their carotenoid content,and OPLS-DA(Orthogonal projections to latent structures)indicated that the levels ofβ-carotene(VIP=2.89)and lutein(VIP=2.30)were responsible for much of the variation between the two groups.Interestingly,theβ-carotene toβ-ionone conversion rates in Group 1 were higher than in Group 2,while theβ-carotene content was significantly lower in Group 1 than in Group 2.Theβ-ionone content was significantly higher in Group 1.Pearson Correlation Coefficient calculation between the transcription level of candidate genes(CsCCD1 and CsCCD4)and the accumulation ofβ-ionone indicated that CsCCD1 may involve in the formation ofβ-ionone in 13 cultivars.Prokaryotic expression and in vitro enzyme activity assays showed that‘Chuanhuang 1’had an amino acid mutation in carotenoid cleavage dioxygenases 1(CsCCD1)compared with‘Shuchazao’,resulting in a significantly higherβ-ionone content in‘Chuanhuang 1’.Sequence analysis showed that‘Chuanhuang 1’and‘Huangdan’had different CsCCD1 promoter sequences,leading to significantly higher CsCCD1 expression andβ-ionone accumulation in‘Chuanhuang 1’.These results indicated that the promoter and coding sequence diversity of CsCCD1 might contribute to the differential accumulation ofβ-ionone in different tea cultivars.
基金This research was funded by National Key Research and Development Program of China(2021YFD1601103 and 2022YFF1003103)National Natural Science Foundation of China(31902075,32150017 and 32022076).
文摘Geraniol is an important contributor to the pleasant floral scent of tea products and one of the most abundant aroma compounds in tea plants;however,its biosynthesis and physiological function in response to stress in tea plants remain unclear.The proteins encoded by the full-length terpene synthase(CsTPS1)and its alternative splicing isoform(CsTPS1-AS)could catalyze the formation of geraniol when GPP was used as a substrate in vitro,whereas the expression of CsTPS1-AS was only significantly induced by Colletotrichum gloeosporioides and Neopestalotiopsis sp.infection.Silencing of CsTPS1 and CsTPS1-AS resulted in a significant decrease of geraniol content in tea plants.The geraniol content and disease resistance of tea plants were compared when CsTPS1 and CsTPS1-AS were silenced.Down-regulation of the expression of CsTPS1-AS reduced the accumulation of geraniol,and the silenced tea plants exhibited greater susceptibility to pathogen infection than control plants.However,there was no significant difference observed in the geraniol content and pathogen resistance between CsTPS1-silenced plants and control plants in the tea plants infected with two pathogens.Further analysis showed that silencing of CsTPS1-AS led to a decrease in the expression of the defense-related genes PR1 and PR2 and SA pathway-related genes in tea plants,which increased the susceptibility of tea plants to pathogens infections.Both in vitro and in vivo results indicated that CsTPS1 is involved in the regulation of geraniol formation and plant defense via alternative splicing in tea plants.The results of this study provide new insights into geraniol biosynthesis and highlight the role of monoterpene synthases in modulating plant disease resistance via alternative splicing.
基金supported by the National Key Research and Development Program of China(2022YFF1003103)the National Natural Science Foundation of China(U22A20499 and 32022076)+1 种基金the Deutsche Forschungsgemeinschaft(DFG SCHW 634/34-1)the China Postdoctoral Science Foundation 2022 M720193。
文摘Plants respond to environmental stimuli via the release of volatile organic compounds(VOCs),and neighboring plants constantly monitor and respond to these VOCs with great sensitivity and discrimination.This sensing can trigger increased plant fitness and reduce future plant damage through the priming of their own defenses.The defense mechanism in neighboring plants can either be induced by activation of the regulatory or transcriptional machinery,or it can be delayed by the absorption and storage of VOCs for the generation of an appropriate response later.Despite much research,many key questions remain on the role of VOCs in interplant communication and plant fitness.Here we review recent research on the VOCs induced by biotic(i.e.insects and pathogens)and abiotic(i.e.cold,drought,and salt)stresses,and elucidate the biosynthesis of stress-induced VOCs in tea plants.Our focus is on the role of stress-induced VOCs in complex ecological environments.Particularly,the roles of VOCs under abiotic stress are highlighted.Finally,we discuss pertinent questions and future research directions for advancing our understanding of plant interactions via VOCs.
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This work was financially supported by the National Natural Science Foundation of China(31961133030,31870678,32022076)the Science Fund for Distinguished Young Scientists of Anhui Province(1908085J12)the Deutsche Forschungsgemeinschaft(SCHW634/32-1 and SCHW634/34-1).
文摘Plants have developed sophisticated mechanisms to survive in dynamic environments.Plants can communicate via volatile organic compounds(VOCs)to warn neighboring plants of threats.In most cases,VOCs act as positive regulators of plant defense.However,the communication and role of volatiles in response to drought stress are poorly understood.Here,we showed that tea plants release numerous VOCs.Among them,methyl salicylate(MeSA),benzyl alcohol,and phenethyl alcohol markedly increased under drought stress.Interestingly,further experiments revealed that drought-induced MeSA lowered the abscisic acid(ABA)content in neighboring plants by reducing 9-cis-epoxycarotenoid dioxygenase(NCED)gene expression,resulting in inhibition of stomatal closure and ultimately decreasing early drought tolerance in neighboring plants.Exogenous application of ABA reduced the wilting of tea plants caused by MeSA exposure.Exposure of Nicotiana benthamiana to MeSA also led to severe wilting,indicating that the ability of drought-induced MeSA to reduce early drought tolerance in neighboring plants may be conserved in other plant species.Taken together,these results provide evidence that drought-induced volatiles can reduce early drought tolerance in neighboring plants and lay a novel theoretical foundation for optimizing plant density and spacing.
文摘After the publication of this article 1,the authors became aware that the word of“tea”was not mentioned in the title.To make the title clear and complete,the word‘tea’is added to the title.
基金supported by the National Key Research and Development Program of China(2018YFD1000601)National Natural Science Founda-tion of China(31961133030,31870678)Science Fundfor Distinguished Young Scientists of Anhui Province(1908085J12).
文摘Plants have evolved sophisticated defense mechanisms to overcome their sessile nature.However,if and how volatiles from cold‐stressed plants can trigger interplant communication is still unknown.Here,we provide the first evidence for interplant communication via inducible volatiles in cold stress.The volatiles,including nerolidol,geraniol,linalool,and methyl salicylate,emitted from cold‐stressed tea plants play key role(s)in priming cold tolerance of their neighbors via a C‐repeatbinding factors‐dependent pathway.The knowledge will help us to understand how plants respond to volatile cues in cold stress and agricultural ecosystems.
基金supported by the National Natural Science Foundation of China(81827802)the National Natural Science Foundation of the Third Affiliated Hospital of Sun Yat-Sen University(2020GZRPYQN17).
文摘Background and Aims:Acute-on-chronic liver failure(ACLF)is associated with very high mortality.Accurate prediction of prognosis is critical in navigating optimal treatment decisions to improve patient survival.This study was aimed to develop a new nomogram integrating two-dimensional shear wave elastography(2D-SWE)values with other independent prognostic factors to improve the precision of predicting ACLF patient outcomes.Methods:A total of 449 consecutive patients with ACLF were recruited and randomly allocated to a training cohort(n=315)or a test cohort(n=134).2D-SWE values,conventional ultrasound features,laboratory tests,and other clinical characteristics were included in univariate and multivariate analysis.Factors with prognostic value were then used to construct a novel prognostic nomogram.Receiver operating curves(ROCs)were generated to evaluate and compare the performance of the novel and published models including the Model for EndStage Liver Disease(MELD),MELD combined with sodium(MELD-Na),and Jin’s model.The model was validated in a prospective cohort(n=102).Results:A ACLF prognostic nomogram was developed with independent prognostic factors,including 2D-SWE,age,total bilirubin(TB),neutrophils(Neu),and the international normalized ratio(INR).The area under the ROC curve(AUC)was 0.849 for the new model in the training cohort and 0.861 in the prospective validation cohort,which were significantly greater than those for MELD(0.758),MELD-Na(0.750),and Jin’s model(0.777,all p<0.05).Calibration curve analysis revealed good agreement between the predicted and observed probabilities.The new nomogram had superior overall net benefit and clinical utility.Conclusions:We established and validated a 2D-SWE-based noninvasive nomogram to predict the prognosis of ACLF patients that was more accurate than other prognostic models.
