Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic be...Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic behaviors to aromatics were investigated. The results indicated that strain WBC-3 was attracted to multiple aromatic compounds, including metabolizable or transformable substrates PNP, 4-nitrocatechol, and hydroquinone. Disruption of PNP catabolic genes had no e?ect on its chemotactic behaviors w...展开更多
Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may ...Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may respond to the action of PGPR.Here,the luciferase luxAB gene was electrotransformed into Pseudomonas sp.strain TK35,a PGPR with an afinity for tobacco,and the labelled TK35(TK35-L)was used to monitor colonization dynamics in the tobacco rhizosphere and evaluate the effects of colonization on tobacco growth and root development.The transcript levels of the hydroxyproline rich glycoprotein HRGPnt3 gene,a lateral root induction indicator,in tobacco roots were examined by qPCR.The results showed that TK35-L could survive for long periods in the tobacco rhizosphere and colonize new spaces in the tobacco rhizosphere following tobacco root extension,exhibiting significant increases in root development,seedling growth and potassium accumulation in tobacco plants.The upregulation of HRGPnt3 transcription in the inoculated tobacco suggested that TK35-L can promote tobacco root development by upregulating the transcript levels of the HRGPnt3 gene,which promotes tobacco seedling growth.These findings lay a foundation for future studies on the molecular mechanism underlying the plant growth-promoting activities of PGPR.Futhermore,this work provided an ideal potential strain for biofertilizer production.展开更多
The design of variants to enhance conformational stability of proteins is an important aspect of protein engineering. Oligomeric proteins are often stabilized by aromatic clusters located within the subunit interfaces...The design of variants to enhance conformational stability of proteins is an important aspect of protein engineering. Oligomeric proteins are often stabilized by aromatic clusters located within the subunit interfaces. In the present study, the authors constructed five variants of Ps3aHSD （Pseudomonas sp. B-0831 3a-hydroxysteroid dehydrogenase） in which one or two residues at the dimer interface were replaced with aromatic residues, and examined the effects of introducing aromatic residues in this region on protein thermostability. Under their experimental conditions, all variants formed dimers, similar to wild-type Ps3aHSD. Thermal denaturation experiments indicated that Tm of all variants was 0.2-16.2 °C lower than that of wild-type protein, indicating less stable thanwild-type protein. The results collectively suggest that aromatic residues of natural oligomeric proteins are strictly posted in the interface to facilitate optimal interactions and avoid conformational strain.展开更多
基金the Hi-Tech Research and Development Program (863) of China (No.2006AA10Z403)the Knowledge Innovation Program ofthe Chinese Academy of Sciences (No. KSCX2-YW-G-009)the National Natural Science Foundation ofChina (No. 30570021)
文摘Pseudomonas sp. strain WBC-3 utilized methyl parathion or para-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy, and methyl parathion hydrolase had been previously characterized. Its chemotactic behaviors to aromatics were investigated. The results indicated that strain WBC-3 was attracted to multiple aromatic compounds, including metabolizable or transformable substrates PNP, 4-nitrocatechol, and hydroquinone. Disruption of PNP catabolic genes had no e?ect on its chemotactic behaviors w...
基金Supported by the National Natural Science Foundation of China(41401269)the Key Project of the University Natural Science Research Project of Anhui Province,China(KJ2019A0183)+1 种基金the Open Fund of Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention(FECPP201902)the Key Research Project of China National Tobacco Corporation Hubei Company(027Y2020-011).
文摘Rhizosphere colonization is a key requirement for the application of plant growth-promoting rhizobacteria(PGPR)as a bioferilizer.Signaling molecules are often exchanged between PGPR and plants,and genes in plants may respond to the action of PGPR.Here,the luciferase luxAB gene was electrotransformed into Pseudomonas sp.strain TK35,a PGPR with an afinity for tobacco,and the labelled TK35(TK35-L)was used to monitor colonization dynamics in the tobacco rhizosphere and evaluate the effects of colonization on tobacco growth and root development.The transcript levels of the hydroxyproline rich glycoprotein HRGPnt3 gene,a lateral root induction indicator,in tobacco roots were examined by qPCR.The results showed that TK35-L could survive for long periods in the tobacco rhizosphere and colonize new spaces in the tobacco rhizosphere following tobacco root extension,exhibiting significant increases in root development,seedling growth and potassium accumulation in tobacco plants.The upregulation of HRGPnt3 transcription in the inoculated tobacco suggested that TK35-L can promote tobacco root development by upregulating the transcript levels of the HRGPnt3 gene,which promotes tobacco seedling growth.These findings lay a foundation for future studies on the molecular mechanism underlying the plant growth-promoting activities of PGPR.Futhermore,this work provided an ideal potential strain for biofertilizer production.
文摘The design of variants to enhance conformational stability of proteins is an important aspect of protein engineering. Oligomeric proteins are often stabilized by aromatic clusters located within the subunit interfaces. In the present study, the authors constructed five variants of Ps3aHSD （Pseudomonas sp. B-0831 3a-hydroxysteroid dehydrogenase） in which one or two residues at the dimer interface were replaced with aromatic residues, and examined the effects of introducing aromatic residues in this region on protein thermostability. Under their experimental conditions, all variants formed dimers, similar to wild-type Ps3aHSD. Thermal denaturation experiments indicated that Tm of all variants was 0.2-16.2 °C lower than that of wild-type protein, indicating less stable thanwild-type protein. The results collectively suggest that aromatic residues of natural oligomeric proteins are strictly posted in the interface to facilitate optimal interactions and avoid conformational strain.
