Transcriptome and proteome analyses provide insight into laticifer's defense of Euphorbia tirucalli against pests
Transcriptome and proteome analyses provide insight into laticifer's defense of Euphorbia tirucalli against pests
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DOI：
10.1016/j.plaphy.2016.08.008
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发表时间：
2016-11-01
影响因子：
6.5
通讯作者：
Aburaya, Shunsuke
中科院分区：
文献类型：
--
作者：
Kitajima, Sakihito;Miura, Kenji;Aburaya, Shunsuke
乳管是专门用于橡胶生产和防御微生物和草食动物的植物细胞，其细胞质是乳胶。虽然乳管具有共同的功能，但胶乳的蛋白质组分在植物物种之间甚至在器官之间具有很大的差异。本研究以地锦草（Euphorbiatirucalli）乳汁为材料，对其进行转录组学和蛋白质组学分析，以确定其乳管功能的分子基础。Illumina mRNA-seq和通过桑格测序获得的表达序列标签的杂交从头组装揭示了26，447个单基因。一个与拟南芥胚胎特异性蛋白3（AT 5G 62200）相似的单基因，这是一个含有PLAT结构域的蛋白，橡胶延伸因子显示出最高的表达水平。蛋白质组分析，研究了液相色谱-质谱与从头组装的unigenes作为数据库，揭示了161个蛋白质的乳胶，其中107个没有检测到的茎。基因本体分析表明，乳管蛋白质组富含与蛋白质水解、磷酸酶、抵御各种环境胁迫和脂质代谢相关的蛋白质。D-甘露糖结合凝集素，蓖麻毒素（缺乏N-末端保守的核糖体失活蛋白结构域），几丁质酶和过氧化物酶的高度积累，证实了由二维聚丙烯酰胺凝胶电泳。因此，凝集素和几丁质酶可能是主要的防御蛋白，而胶乳中检测到的其他防御相关蛋白和转录物可能与它们协同作用。高表达的功能未知的unigene是与橡胶树防御或橡胶生产相关的候选新基因。(C)2016 Elsevier Masson SAS。All rights reserved.
The cytoplasm of laticifers, which are plant cells specialized for rubber production and defense against microbes and herbivores, is a latex. Although laticifers share common functions, the protein constituents of latexes are highly variable among plant species and even among organs. In this study, transcriptomic and proteomic analyses of Euphorbia tirucalli's (Euphorbiaceae) latex were conducted to determine the molecular basis of the laticifer's functions in this plant. The hybrid de novo assembly of Illumina mRNA-seq and expressed sequence tags obtained by Sanger's sequencing revealed 26,447 unigenes. A unigene similar to Arabidopsis embryo-specific protein 3 (AT5G62200), which is a PLAT domain-containing protein, and rubber elongation factor showed the highest expression levels. The proteome analysis, studied by liquid chromatography-mass spectrometry with the de novo assembled unigenes as the database, revealed 161 proteins in the latex, 107 of which were not detected in the stem. A gene ontology analysis indicated that the laticifer's proteome was enriched with proteins related to proteolysis, phosphatase, defense against various environmental stresses and lipid metabolisms. D-mannose-binding lectin, ricin (which lacked the N-terminal conserved ribosome-inactivating protein domain), chitinase and peroxidase were highly accumulated, as confirmed by two-dimensional polyacrylamide gel electrophoresis. Thus, the lectins and chitinase may be the major defensive proteins against pests, and the other defense-related proteins and transcripts detected in latex may work in coordination with them. Highly expressing unigenes with unknown functions are candidate novel defense- or rubber production related genes. (C) 2016 Elsevier Masson SAS. All rights reserved.