Plants can produce animal cytokine-like immune peptides,among which plant elicitor peptides(Peps)derive from the C termini of their precursors(PROPEPs).Recently,the functions of Peps have been expanded beyond plant im...Plants can produce animal cytokine-like immune peptides,among which plant elicitor peptides(Peps)derive from the C termini of their precursors(PROPEPs).Recently,the functions of Peps have been expanded beyond plant immunity.However,a long-standing enigma is how PROPEPs are processed into Peps.Here,we report that the Ca2+-dependent type-ll metacaspases(MCs)constitute the proteolytic enzymes to mediate PROPEP processing in Arabidopsis.In protoplasts,co-expression of PROPEP1 with type-ll MCs,including MC4 to MC9,can promote the generation of processed Pep1.Destruction of the catalytic cysteine residue in MC4 or the conserved arginine residue preceding the Pep1 sequence blocks PROPEP1 cleavage,whereas the bacterial elicitor flg22 enhances the MC4-mediated PROPEP1 processing.MC4 cleaves PROPEP1 in vitro and also cleaves PROPEP2 to PROPEP8,but,surprisingly,not PROPEP6 in protoplasts.Domain swapping between PROPEP1 and PROPEP6 suggests a hidden role of the sequence context upstream of the Pep sequence for PROPEP processing.flg22-induced PROPEP1 processing and B otrytis cinerea resistance are severely impaired in the m c4/5/6/7 quadruple-mutant plants.Taken together,our study identifies the type-ll MCs as new players in Pep signaling,and lays the foundation for understanding the regulation of multifaceted functions of Peps in plant immunity and beyond.展开更多
以原核表达的番茄SlMC7重组蛋白为抗原,制备SlMC7多克隆抗体,采用ELISA和蛋白质点杂的方法,研究了番茄II型metacaspase蛋白(SlMC7)的抗体效价和表达特性,并对SlMC7蛋白及基因在番茄果实发育过程中的表达差异进行了研究,以期为后续的SlMC...以原核表达的番茄SlMC7重组蛋白为抗原,制备SlMC7多克隆抗体,采用ELISA和蛋白质点杂的方法,研究了番茄II型metacaspase蛋白(SlMC7)的抗体效价和表达特性,并对SlMC7蛋白及基因在番茄果实发育过程中的表达差异进行了研究,以期为后续的SlMC7在番茄果实中功能性研究提供材料基础和参考依据。结果表明:SlMC7多克隆抗体效价在256 000以上,在1∶10 000的稀释度下,可识别低至1.6ng的纯蛋白。对各时期番茄果实Western-blot和Real time PCR结果表明,相对于绿熟期,SlMC7蛋白及基因在破色期果实中表达量显著上升,表明SlMC7与番茄果实成熟存在一定相关性。展开更多
SlMC7 prokaryotic expression recombinant protein was used as test materials. SlMC7 polyclonal antiserum was obtained from immunized mice by using purified SlMC7 recombinant protein from Escherichia coli. ELISA and pro...SlMC7 prokaryotic expression recombinant protein was used as test materials. SlMC7 polyclonal antiserum was obtained from immunized mice by using purified SlMC7 recombinant protein from Escherichia coli. ELISA and protein dot plot methods were used to detect the antibody titer and expression characteristics and the expression difference at different stages,providing material foundation and reference basis for subsequent SlMC7 functional research in tomato fruit. The results showed that the titer of SlMC7 polyclonal antibodies was more than 1∶ 256 000 and the sensitivity of SlMC7 polyclonal antibodies was 1. 6 ng at the dilutability of 1∶ 10 000. SlMC7 protein was detected at different stages,and SlMC7 had a higher expression level in color-break fruit,indicating that SlMC7 might be relevant to the fruit ripening of tomato.展开更多
During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, prog...During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed celldeath （PCD） has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.展开更多
基金This work was supported by the Foundation of Guangzhou Science and Technology Key Project(201904020041)the National Natural Science Foundation of China(31770295)to J.-F.L.
文摘Plants can produce animal cytokine-like immune peptides,among which plant elicitor peptides(Peps)derive from the C termini of their precursors(PROPEPs).Recently,the functions of Peps have been expanded beyond plant immunity.However,a long-standing enigma is how PROPEPs are processed into Peps.Here,we report that the Ca2+-dependent type-ll metacaspases(MCs)constitute the proteolytic enzymes to mediate PROPEP processing in Arabidopsis.In protoplasts,co-expression of PROPEP1 with type-ll MCs,including MC4 to MC9,can promote the generation of processed Pep1.Destruction of the catalytic cysteine residue in MC4 or the conserved arginine residue preceding the Pep1 sequence blocks PROPEP1 cleavage,whereas the bacterial elicitor flg22 enhances the MC4-mediated PROPEP1 processing.MC4 cleaves PROPEP1 in vitro and also cleaves PROPEP2 to PROPEP8,but,surprisingly,not PROPEP6 in protoplasts.Domain swapping between PROPEP1 and PROPEP6 suggests a hidden role of the sequence context upstream of the Pep sequence for PROPEP processing.flg22-induced PROPEP1 processing and B otrytis cinerea resistance are severely impaired in the m c4/5/6/7 quadruple-mutant plants.Taken together,our study identifies the type-ll MCs as new players in Pep signaling,and lays the foundation for understanding the regulation of multifaceted functions of Peps in plant immunity and beyond.
文摘以原核表达的番茄SlMC7重组蛋白为抗原,制备SlMC7多克隆抗体,采用ELISA和蛋白质点杂的方法,研究了番茄II型metacaspase蛋白(SlMC7)的抗体效价和表达特性,并对SlMC7蛋白及基因在番茄果实发育过程中的表达差异进行了研究,以期为后续的SlMC7在番茄果实中功能性研究提供材料基础和参考依据。结果表明:SlMC7多克隆抗体效价在256 000以上,在1∶10 000的稀释度下,可识别低至1.6ng的纯蛋白。对各时期番茄果实Western-blot和Real time PCR结果表明,相对于绿熟期,SlMC7蛋白及基因在破色期果实中表达量显著上升,表明SlMC7与番茄果实成熟存在一定相关性。
基金Supported by National Natural Science Foundation of China(31672207)
文摘SlMC7 prokaryotic expression recombinant protein was used as test materials. SlMC7 polyclonal antiserum was obtained from immunized mice by using purified SlMC7 recombinant protein from Escherichia coli. ELISA and protein dot plot methods were used to detect the antibody titer and expression characteristics and the expression difference at different stages,providing material foundation and reference basis for subsequent SlMC7 functional research in tomato fruit. The results showed that the titer of SlMC7 polyclonal antibodies was more than 1∶ 256 000 and the sensitivity of SlMC7 polyclonal antibodies was 1. 6 ng at the dilutability of 1∶ 10 000. SlMC7 protein was detected at different stages,and SlMC7 had a higher expression level in color-break fruit,indicating that SlMC7 might be relevant to the fruit ripening of tomato.
文摘During the diversification of angiosperms, seeds have evolved structuralp chemical, molecular and physiolog- ically developing changes that specially affect the nucellus and endosperm. All through seed evolution, programmed celldeath （PCD） has played a fundamental role. However, examples of PCD during seed development are limited. The present review examines PCD in integuments, nucellus, suspensor and endosperm in those representative examples of seeds studied to date.
