Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, 710069, China; and Collaborative Innovation Center of Green Manufacturing Technology for Traditional Chinese Medicine in Shaanxi Province, School of Pharmacy, Shaanxi Institute of International Trade and Commerce, Xianyang, 712046, China.
Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, 710069, China.
Funct Plant Biol. 2019 Jan;47(1):67-79. doi: 10.1071/FP19033.
Euphorbia kansui Liou, an endemic species in China, is well-known in traditional Chinese medicine. All parts of E. kansui contain white latex, which is the protoplasm constituent of specialised cells known as laticifers. The latex contains many proteins with various biological functions. In the present study, isobaric tagging for relative and absolute quantitation (iTRAQ) and MS technology combined with western blot and quantitative real-time PCR analysis were used to identify latex proteins and analyse differentially accumulated proteins in laticifers at different development stages, with and without UV-B treatment according to the E. kansui transcriptome database and the NCBI Euphorbiaceae RefSeq protein database. A total of 322 latex proteins were successfully identified. Proteasome subunits, ubiquitinated proteins, vacuolar ATP synthase (V-ATPase) and lysosomal enzymes decreased, keeping the content at a higher level in laticifers in the early development stage. These results suggest that the ubiquitin-proteasome pathway and the lysosome autophagy pathway were involved in the partial degradation of laticifer cytoplasm. In addition, terpenoid biosynthesis-related proteins, 14-3-3 protein, V-ATPase and lysosomal enzymes increased under UV-B treatment, which showed that partial cytoplasmic degradation is positively correlated with secondary metabolite synthesis in the development of E. kansui laticifers. Besides, UV-B radiation can increase plant resistance by promoting laticifer development in E. kansui. This information provides a basis for further exploration of E. kansui laticifer development, and terpenoid synthesis and regulation.
瑞香狼毒 Liou，中国特有的物种，在中国传统医学中广为人知。瑞香狼毒的所有部分都含有白色乳汁，这是一种称为乳汁道的特化细胞的原生质组成部分。乳汁中含有许多具有各种生物功能的蛋白质。在本研究中，根据瑞香狼毒转录组数据库和 NCBI 大戟科 RefSeq 蛋白质数据库，使用相对和绝对定量同位素标记（iTRAQ）和 MS 技术结合 Western blot 和定量实时 PCR 分析，鉴定了乳汁道中不同发育阶段、有无 UV-B 处理的乳汁蛋白质和分析差异积累蛋白质。总共成功鉴定了 322 种乳汁蛋白质。蛋白酶体亚基、泛素化蛋白质、液泡型 ATP 合酶（V-ATPase）和溶酶体酶减少，使早期发育阶段乳汁道中的蛋白质含量保持在较高水平。这些结果表明，泛素-蛋白酶体途径和溶酶体自噬途径参与了乳汁细胞质的部分降解。此外，萜类生物合成相关蛋白、14-3-3 蛋白、V-ATPase 和溶酶体酶在 UV-B 处理下增加，表明部分细胞质降解与瑞香狼毒乳汁道发育过程中次生代谢物的合成呈正相关。此外，UV-B 辐射可以通过促进瑞香狼毒乳汁道的发育来增加植物的抗性。这些信息为进一步探索瑞香狼毒乳汁道的发育、萜类化合物的合成和调控提供了依据。
