根据烟草Nt-syr1基因mRNA序列设计特异引物,建立了SYBR Green I实时荧光定量PCR反应体系,对烟株打顶后叶片Nt-syr1基因进行了mRNA转录水平上的定量分析,为从分子生物学水平上研究烤烟钾素营养调控机理提供新的技术手段。该方法简单实用...根据烟草Nt-syr1基因mRNA序列设计特异引物,建立了SYBR Green I实时荧光定量PCR反应体系,对烟株打顶后叶片Nt-syr1基因进行了mRNA转录水平上的定量分析,为从分子生物学水平上研究烤烟钾素营养调控机理提供新的技术手段。该方法简单实用,获得的荧光定量PCR扩增曲线基线平整,指数区扩增明显,斜率大;稳定性和重现性好,变异系数小;循环阈值Ct与PCR起始模板量的对数值之间存在良好的线性关系。对基因表达结果分析表明,烟株打顶后1 h,Nt-syr1基因在叶片中强烈表达,表达量约是同期不打顶处理的480倍,随后逐渐降低。与打顶处理相比,打顶后涂抹生长调节剂可以降低其表达量。展开更多
Systemin, the first peptide hormone identified in plants, was initially isolated from tomato(Solanum lycopersicum) leaves. Systemin mediates local and systemic wound-induced defense responses in plants, conferring res...Systemin, the first peptide hormone identified in plants, was initially isolated from tomato(Solanum lycopersicum) leaves. Systemin mediates local and systemic wound-induced defense responses in plants, conferring resistance to necrotrophic fungi and herbivorous insects. Systemin is recognized by the leucine-rich-repeat receptor-like kinase(LRRRLK) receptor SYSTEMIN RECEPTOR1(SYR1), but how the systemin recognition signal is transduced to intracellular signaling pathways to trigger defense responses is poorly understood. Here, we demonstrate that SERK family LRR-RLKs function as coreceptors for SYR1 to mediate systemin signal transduction in tomato. By using chemical genetic approaches coupled with engineered receptors, we revealed that the association of the cytoplasmic kinase domains of SYR1 with SERKs leads to their mutual trans-phosphorylation and the activation of SYR1, which in turn induces a wide range of defense responses. Systemin stimulates the association between SYR1 and all tomato SERKs(SlSERK1,SlSERK3A, and SlSERK3B). The resulting SYR1-SlSERK heteromeric complexes trigger the phosphorylation of TOMATO PROTEIN KINASE 1B(TPK1b), a receptor-like cytoplasmic kinase that positively regulates systemin responses. Additionally,upon association with SYR1, SlSERKs are cleaved by the Pseudomonas syringae effector HopB1, further supporting the finding that SlSERKs are activated by systemin-bound SYR1. Finally, genetic analysis using Slserk mutants showed that SlSERKs are essential for systemin-mediated defense responses. Collectively, these findings demonstrate that the systeminmediated association of SYR1 and SlSERKs activates defense responses against herbivorous insects.展开更多
AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （...AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （ABA） and ethylene stimulus ATSYR1 gene encodes a syntaxin localizing at the plasma membrane in Arabidopsis, which can be induced by abiotic stress. To identify mutation lines for gene functional analysis, real-time PCR was employed to detect the expression level of AtERF4 and ATSYR1 in homozygous T-DNA insertion mutant line, respectively. Real-time PCR is a powerful tool which can be used to detect steady-state mRNA levels specifically, sensitively and reproducibly. Comparing to other forms of quantitative RT-PCR, the amount of amplified products can be detected by real-time PCR instantly and thus is a preferable alternative. In this study, RNA with T-DNA inserting into exon could be detected in AtERF4 knock-out mutation line. The results indicated that AtERF4 had been trucked in transcription level. On the other hand, T-DNA inserting into the promoter of gene ATSYR1 had no effect on reducing the expression level ofATSYR1 gene. Further molecular and phenotype studies now are ongoing to clarify the potential consequences of AtERF4 and ATSYR1 deficiency in Arabidopsis展开更多
文摘根据烟草Nt-syr1基因mRNA序列设计特异引物,建立了SYBR Green I实时荧光定量PCR反应体系,对烟株打顶后叶片Nt-syr1基因进行了mRNA转录水平上的定量分析,为从分子生物学水平上研究烤烟钾素营养调控机理提供新的技术手段。该方法简单实用,获得的荧光定量PCR扩增曲线基线平整,指数区扩增明显,斜率大;稳定性和重现性好,变异系数小;循环阈值Ct与PCR起始模板量的对数值之间存在良好的线性关系。对基因表达结果分析表明,烟株打顶后1 h,Nt-syr1基因在叶片中强烈表达,表达量约是同期不打顶处理的480倍,随后逐渐降低。与打顶处理相比,打顶后涂抹生长调节剂可以降低其表达量。
基金supported by the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2022R1A4A3024451 and NRF2023R1A2C3002386)a grant from Korea University。
文摘Systemin, the first peptide hormone identified in plants, was initially isolated from tomato(Solanum lycopersicum) leaves. Systemin mediates local and systemic wound-induced defense responses in plants, conferring resistance to necrotrophic fungi and herbivorous insects. Systemin is recognized by the leucine-rich-repeat receptor-like kinase(LRRRLK) receptor SYSTEMIN RECEPTOR1(SYR1), but how the systemin recognition signal is transduced to intracellular signaling pathways to trigger defense responses is poorly understood. Here, we demonstrate that SERK family LRR-RLKs function as coreceptors for SYR1 to mediate systemin signal transduction in tomato. By using chemical genetic approaches coupled with engineered receptors, we revealed that the association of the cytoplasmic kinase domains of SYR1 with SERKs leads to their mutual trans-phosphorylation and the activation of SYR1, which in turn induces a wide range of defense responses. Systemin stimulates the association between SYR1 and all tomato SERKs(SlSERK1,SlSERK3A, and SlSERK3B). The resulting SYR1-SlSERK heteromeric complexes trigger the phosphorylation of TOMATO PROTEIN KINASE 1B(TPK1b), a receptor-like cytoplasmic kinase that positively regulates systemin responses. Additionally,upon association with SYR1, SlSERKs are cleaved by the Pseudomonas syringae effector HopB1, further supporting the finding that SlSERKs are activated by systemin-bound SYR1. Finally, genetic analysis using Slserk mutants showed that SlSERKs are essential for systemin-mediated defense responses. Collectively, these findings demonstrate that the systeminmediated association of SYR1 and SlSERKs activates defense responses against herbivorous insects.
基金Supported by National High Technology Program (2008ZX08004-002, 2009ZX08009-032B)Key Research Plan of Heilongjiang Province (GA06B103)Education Department Plan of Heilongjiang Province(11521021, 1152024)
文摘AtERF4 （ethylene response factor） is a negative regulator in jasmonic acid mediated signal transduction pathway and ethylene mediated signal transduction pathway of Arabidopsis. It could respond to abscisic acid （ABA） and ethylene stimulus ATSYR1 gene encodes a syntaxin localizing at the plasma membrane in Arabidopsis, which can be induced by abiotic stress. To identify mutation lines for gene functional analysis, real-time PCR was employed to detect the expression level of AtERF4 and ATSYR1 in homozygous T-DNA insertion mutant line, respectively. Real-time PCR is a powerful tool which can be used to detect steady-state mRNA levels specifically, sensitively and reproducibly. Comparing to other forms of quantitative RT-PCR, the amount of amplified products can be detected by real-time PCR instantly and thus is a preferable alternative. In this study, RNA with T-DNA inserting into exon could be detected in AtERF4 knock-out mutation line. The results indicated that AtERF4 had been trucked in transcription level. On the other hand, T-DNA inserting into the promoter of gene ATSYR1 had no effect on reducing the expression level ofATSYR1 gene. Further molecular and phenotype studies now are ongoing to clarify the potential consequences of AtERF4 and ATSYR1 deficiency in Arabidopsis
