The non-specific lipid transfer proteins （nsLTPs） are small, basic proteins characterized by a tunnel-like hydrophobic cavity, capable of transferring various lipid molecules between lipid bilayers. Most nsLTPs are ...The non-specific lipid transfer proteins （nsLTPs） are small, basic proteins characterized by a tunnel-like hydrophobic cavity, capable of transferring various lipid molecules between lipid bilayers. Most nsLTPs are synthesized with an N-terminal signal peptide that localizes the protein to the apoplastic space. The nsLTPs have only been identified in seed plants, where they are encoded by large gene families. We have initiated an analysis of the evolutionary history of the nsLTP family using genomic and EST information from non-seed land plants and green algae to determine： （1） when the nsLTP family arose, （2） how often new nsLTP subfamilies have been created, and （3） how subfamilies differ in their patterns of expansion and loss in different plant lineages. In this study, we searched sequence databases and found that genes and transcripts encoding nsLTPs are abundant in liverworts, mosses, and all other investigated land plants, but not present in any algae. The tertiary structures of representative liverwort and moss nsLTPs were further studied with homology modeling. The results indicate that the nsLTP family has evolved after plants conquered land. Only two of the four major subfamilies of nsLTPs found in flowering plants are present in mosses and liverworts. The additional subfamilies have arisen later, during land plant evolution. In this report, we also introduce a modified nsLTP classification system.展开更多
为了解中国现存石松类和蕨类植物的灭绝风险,我们按照IUCN Red List Categories and Criteria(Version3.1)首次开展了国家水平上的红色名录评估。三人评估小组通过查阅文献、标本以及向其他30位中国蕨类同行征询物种信息等途径,历经16...为了解中国现存石松类和蕨类植物的灭绝风险,我们按照IUCN Red List Categories and Criteria(Version3.1)首次开展了国家水平上的红色名录评估。三人评估小组通过查阅文献、标本以及向其他30位中国蕨类同行征询物种信息等途径,历经16个月的时间完成了此次评估。经统计,中国目前所知的石松类和蕨类植物共计2,244种(包括亚种和变种,但不包括变型和杂交种)。评估结果为:极危(CR)43种(其中6种可能已经灭绝)、濒危(EN)68种、易危(VU)71种、近危(NT)66种、无危(LC)1,124种、数据缺乏(DD)872种。受威胁种类(包括VU、EN、CR)共计182种,其中79种为中国特有或准特有种。特有而又极度濒危的植物有24种,分别是梅山铁线蕨(Adiantum meishanianum)、荷叶铁线蕨(A.nelumboides)、秦氏莲座蕨(Angiopteris chingii)、壮乡铁角蕨(Asplenium cornutissimum)、海南实蕨(Bolbitis hainanensis)、直叶金发石杉(Huperzia quasipolytrichoides var.rectifolia)、东方水韭(Iso?tes orientalis)、台湾水韭(I.taiwanensis)、云贵水韭(I.yunguiensis)、台湾曲轴蕨(Paesia taiwanensis)、海南金星蕨(Parathelypteris subimmersa)、基羽鞭叶耳蕨(Polystichum basipinnatum)、洞生耳蕨(P.cavernicola)、微小耳蕨(P.minutissimum)、倒披针耳蕨(P.oblanceolatum)、岩穴耳蕨(P.speluncicola)、长柄新月蕨(Pronephrium longipetiolatum)、尾羽假毛蕨(Pseudocyclosorus caudipinnus)、罗浮牙蕨(Pteridrys lofouensis)、细叶凤尾蕨(Pteris angustipinna)、十字假瘤蕨(Selliguea cruciformis)、黑柄叉蕨(Tectaria ebenina)、河口叉蕨(T.hekouensis)和冈本氏岩蕨(Woodsia okamotoi),它们应予以最优先保护。目前的红色名录只是一个初步评估结果,若要得到一份更完整更准确的红色名录,我们还需要做进一步的信息收集和评估工作,特别要加强中国石松类和蕨类植物的分类学研究。今后评估工作中应重点关注的类群主要有莲座蕨属(Angiopteris)、铁角蕨属(Asple展开更多
文摘The non-specific lipid transfer proteins （nsLTPs） are small, basic proteins characterized by a tunnel-like hydrophobic cavity, capable of transferring various lipid molecules between lipid bilayers. Most nsLTPs are synthesized with an N-terminal signal peptide that localizes the protein to the apoplastic space. The nsLTPs have only been identified in seed plants, where they are encoded by large gene families. We have initiated an analysis of the evolutionary history of the nsLTP family using genomic and EST information from non-seed land plants and green algae to determine： （1） when the nsLTP family arose, （2） how often new nsLTP subfamilies have been created, and （3） how subfamilies differ in their patterns of expansion and loss in different plant lineages. In this study, we searched sequence databases and found that genes and transcripts encoding nsLTPs are abundant in liverworts, mosses, and all other investigated land plants, but not present in any algae. The tertiary structures of representative liverwort and moss nsLTPs were further studied with homology modeling. The results indicate that the nsLTP family has evolved after plants conquered land. Only two of the four major subfamilies of nsLTPs found in flowering plants are present in mosses and liverworts. The additional subfamilies have arisen later, during land plant evolution. In this report, we also introduce a modified nsLTP classification system.
