Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell w...Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.展开更多
The densities and surface tensions of [Bmim][TFO]/H2SO4, [Hmim][TFO]/H2SO4 and [Omim][TFO]/H2SO4 binary mixtures were measured by pycnometer and Wilhelmy plate method respectively. The results show that densities and ...The densities and surface tensions of [Bmim][TFO]/H2SO4, [Hmim][TFO]/H2SO4 and [Omim][TFO]/H2SO4 binary mixtures were measured by pycnometer and Wilhelmy plate method respectively. The results show that densities and surface tensions of the mixtures decreased monotonously with increasing temperatures and increasing ionic liquid （IL） molar fraction. IL with longer alkyl side-chain length brings a lower density and a smaller surface tension to the ILs/H2SO4 binary mixtures. The densities and surface tensions of the mixtures are fitted well by Jouyban-Acree （JAM） model and LWW model respectively. Redlich-Kister （R-K）equation and modified Redlich-Kister （R-K） equation describe the excess molar volumes and excess surface tensions of the mixtures well respectively. Adding a small amount of ILs （XIL 〈 0.1 ） into sulfuric acid brings an obvious decrease to the density and the surface tension. The results imply that the densities and surface tensions of IL5/H2SO4 binary mixtures can be modulated by changing the IL dosage or tailoring the IL structure.展开更多
After the strong earthquake centered in Wenchuan County in the Southwestern Chinese Sichuan Province took place,the CCPIT Overseas Representative Of- fices immediately responding to the call of the
UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum int...UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum into PQE-30, the prokaryotic expression vector of PQE-UGP was successfully constructed. Then the vector plasmid of PQE-UGP was transformed into host bacteria M 15 and the expression of target gene was induced by Isopropyl β-D-1-Thiogalactopyranoside （IPTG）. The research laid foundation for study on the prokaryotic expression of UGPase.展开更多
Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum ...Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum root transcriptome were obtained via lllumina HiSeq 2000 sequencing. A total of 86418 urtigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid （MVA）, methyl-D-erythritol 4-phosphate （MEP）, shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthra- quinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.展开更多
Sesquiterpenoids are a class of 15-carbon secondary metabolites that play diverse roles in plant adaptation to environment. Cotton plants accumulate a large amount of sesquiterpene aldehydes （including gossypol） as ...Sesquiterpenoids are a class of 15-carbon secondary metabolites that play diverse roles in plant adaptation to environment. Cotton plants accumulate a large amount of sesquiterpene aldehydes （including gossypol） as phytoalexins against pathogens and herbivores. They are stored in pigment glands of aerial organs and in epidermal layers of roots. Several enzymes of goss- ypol biosynthesis pathway have been characterized, including 3-hydroxy-3-methylglutaryl coenzyme A reductase （HMGR） and farnesyl diphosphate synthase （FPS） that catalyze the formation of the precursor farnesyl diphosphate （FPP）, （＋）-6-cadinene synthase （CDN） which is the first enzyme committed to gossypol biosynthesis, and the downstream enzymes of CYP706B 1 and methyltransferase. Expressions of these genes are tightly regulated during cotton plants development and in- duced by jasmonate and fungi elicitors. The transcription factor GaWRKY1 has been shown to be involved in gossypol path- way regulation. Recent development of new genomic platforms and methods and releases of diploid and tetraploid cotton ge- nome sequences will greatly facilitate the elucidation of gossypol biosynthetic pathway and its regulation.展开更多
文摘Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.
基金Supported by the National Natural Science Foundation of China(21576168,21276163)
文摘The densities and surface tensions of [Bmim][TFO]/H2SO4, [Hmim][TFO]/H2SO4 and [Omim][TFO]/H2SO4 binary mixtures were measured by pycnometer and Wilhelmy plate method respectively. The results show that densities and surface tensions of the mixtures decreased monotonously with increasing temperatures and increasing ionic liquid （IL） molar fraction. IL with longer alkyl side-chain length brings a lower density and a smaller surface tension to the ILs/H2SO4 binary mixtures. The densities and surface tensions of the mixtures are fitted well by Jouyban-Acree （JAM） model and LWW model respectively. Redlich-Kister （R-K）equation and modified Redlich-Kister （R-K） equation describe the excess molar volumes and excess surface tensions of the mixtures well respectively. Adding a small amount of ILs （XIL 〈 0.1 ） into sulfuric acid brings an obvious decrease to the density and the surface tension. The results imply that the densities and surface tensions of IL5/H2SO4 binary mixtures can be modulated by changing the IL dosage or tailoring the IL structure.
文摘After the strong earthquake centered in Wenchuan County in the Southwestern Chinese Sichuan Province took place,the CCPIT Overseas Representative Of- fices immediately responding to the call of the
文摘UGPase （UDP-glucose pyrophosphorylase）, one of the primary enzymes concerned with carbohydrate metabolism, catalyzes the formation of UDPG. By inserting the UGPase cDNA fragment cloned from Saccharum officinarum into PQE-30, the prokaryotic expression vector of PQE-UGP was successfully constructed. Then the vector plasmid of PQE-UGP was transformed into host bacteria M 15 and the expression of target gene was induced by Isopropyl β-D-1-Thiogalactopyranoside （IPTG）. The research laid foundation for study on the prokaryotic expression of UGPase.
基金supported by the National Science and Technology Major Program (Grant No.2008ZX10005-004)
文摘Various active components have been extracted from the root of Polygonum cuspidatum. However, the genetic basis for their activity is virtually unknown. In this study, 25600002 short reads （2.3 Gb） of P. cuspidatum root transcriptome were obtained via lllumina HiSeq 2000 sequencing. A total of 86418 urtigenes were assembled de novo and annotated. Twelve, 18, 60 and 54 unigenes were respectively mapped to the mevalonic acid （MVA）, methyl-D-erythritol 4-phosphate （MEP）, shikimate and resveratrol biosynthesis pathways, suggesting that they are involved in the biosynthesis of pharmaceutically important anthra- quinone and resveratrol. Eighteen potential UDP-glycosyltransferase unigenes were identified as the candidates most likely to be involved in the biosynthesis of glycosides of secondary metabolites. Identification of relevant genes could be important in eventually increasing the yields of the medicinally useful constituents of the P. cuspidatum root. From the previously published transcriptome data of 19 non-model plant taxa, 1127 shared orthologs were identified and characterized. This information will be very useful for future functional, phylogenetic and evolutionary studies of these plants.
基金the State Key Basic Research Program of China (2013CB127000)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB11030300)+1 种基金the National Natural Science Foundation of China (31300255)the Special Fund for Shanghai Landscaping Administration Bureau Program (G142425, F112418).
文摘Sesquiterpenoids are a class of 15-carbon secondary metabolites that play diverse roles in plant adaptation to environment. Cotton plants accumulate a large amount of sesquiterpene aldehydes （including gossypol） as phytoalexins against pathogens and herbivores. They are stored in pigment glands of aerial organs and in epidermal layers of roots. Several enzymes of goss- ypol biosynthesis pathway have been characterized, including 3-hydroxy-3-methylglutaryl coenzyme A reductase （HMGR） and farnesyl diphosphate synthase （FPS） that catalyze the formation of the precursor farnesyl diphosphate （FPP）, （＋）-6-cadinene synthase （CDN） which is the first enzyme committed to gossypol biosynthesis, and the downstream enzymes of CYP706B 1 and methyltransferase. Expressions of these genes are tightly regulated during cotton plants development and in- duced by jasmonate and fungi elicitors. The transcription factor GaWRKY1 has been shown to be involved in gossypol path- way regulation. Recent development of new genomic platforms and methods and releases of diploid and tetraploid cotton ge- nome sequences will greatly facilitate the elucidation of gossypol biosynthetic pathway and its regulation.
