Jasmonate(JA),as an important signal,plays a key role in multiple processes of plant growth,development and stress response.Nicotine and related pyridine alkaloids in tobacco(Nicotiana tabacum L.) are essential second...Jasmonate(JA),as an important signal,plays a key role in multiple processes of plant growth,development and stress response.Nicotine and related pyridine alkaloids in tobacco(Nicotiana tabacum L.) are essential secondary metabolites.Whether environmental factors control nicotine biosynthesis and the underlying mechanism remains previously unreported.Here,we applied physiological and biochemical approaches to investigate how salt stress affects nicotine biosynthesis in tobacco.We found that salt stress induced the biosynthesis of JA,which subsequently triggered the activation of JA-responsive gene expression and,ultimately,nicotine synthesis.Bioinformatics analysis revealed the existence of many Nt MYC2a-recognized G-box motifs in the promoter regions of Nt LOX,Nt AOS,Nt AOC and Nt OPR genes.Applying exogenous JA increased nicotine content,while suppressing JA biosynthesis reduced nicotine biosynthesis.Salt treatment could not efficiently induce nicotine biosynthesis in transgenic anti-COI1 tobacco plants.These results demonstrate that JA acts as the essential signal which triggers nicotine biosynthesis in tobacco after salt stress.展开更多
Staphylococci are Gram-positive, AT-rich cocci, and often stick together in grape-like clusters. The genus can be classified into two groups based on their ability to produce coagulase, an enzyme that causes clotting ...Staphylococci are Gram-positive, AT-rich cocci, and often stick together in grape-like clusters. The genus can be classified into two groups based on their ability to produce coagulase, an enzyme that causes clotting of blood plasma （Otto, 2004）. Coagulase-positive Staphylococci include Staphylococcus aureus, a common pathogen of community-acquired and nosocomial infections （Smith et al., 2009）.展开更多
基金supported by the Major Science and Technology Program NOs.110201101003-TS-03,2011YN02 and 2011YN03
文摘Jasmonate(JA),as an important signal,plays a key role in multiple processes of plant growth,development and stress response.Nicotine and related pyridine alkaloids in tobacco(Nicotiana tabacum L.) are essential secondary metabolites.Whether environmental factors control nicotine biosynthesis and the underlying mechanism remains previously unreported.Here,we applied physiological and biochemical approaches to investigate how salt stress affects nicotine biosynthesis in tobacco.We found that salt stress induced the biosynthesis of JA,which subsequently triggered the activation of JA-responsive gene expression and,ultimately,nicotine synthesis.Bioinformatics analysis revealed the existence of many Nt MYC2a-recognized G-box motifs in the promoter regions of Nt LOX,Nt AOS,Nt AOC and Nt OPR genes.Applying exogenous JA increased nicotine content,while suppressing JA biosynthesis reduced nicotine biosynthesis.Salt treatment could not efficiently induce nicotine biosynthesis in transgenic anti-COI1 tobacco plants.These results demonstrate that JA acts as the essential signal which triggers nicotine biosynthesis in tobacco after salt stress.
基金supported by the grants from the National Natural Science Foundation of China(Nos.81301475,31170131 and 31070312)Jiangsu Qinglan Project,and the Shaoxing Major Scientific and Technological Projects(No.2011A11013)
文摘Staphylococci are Gram-positive, AT-rich cocci, and often stick together in grape-like clusters. The genus can be classified into two groups based on their ability to produce coagulase, an enzyme that causes clotting of blood plasma （Otto, 2004）. Coagulase-positive Staphylococci include Staphylococcus aureus, a common pathogen of community-acquired and nosocomial infections （Smith et al., 2009）.
