Data_Sheet_1_Proteomic Response to Environmental Stresses in the Stolon of a Highly Invasive Fouling Ascidian.DOCX

Ascidians, particularly those highly invasive ones, are typical fouling organisms to cause significantly negative ecological and economic influence in coastal ecosystems. Stolon, which is the unique structure of some solitary ascidians to complete the essential process of adhesion, possesses extremely high tolerance to environmental stresses during biofouling and invasions. However, the mechanisms underlying environmental tolerance remain largely unknown. Here, we used the quantitative proteomics technology, isobaric tags for relative and absolute quantitation (iTRAQ), to investigate the molecular response to environmental challenges (temperature and salinity) in the stolon of a highly invasive fouling ascidian, Ciona robusta. When compared with the control, a total of 75, 86, 123, and 83 differential abundance proteins were identified under low salinity, high salinity, low temperature, and high temperature stress, respectively. Bioinformatic analyses uncovered the key pathways under both temperature and salinity stresses, including “cytoskeleton,” “signal transduction,” and “posttranslational modification,” which were involved in stolon structure stability, protein synthesis, and stress response activation. Under the low salinity stress, the “extracellular matrix” pathway was identified to play a crucial role by regulating cell signal transduction and protein synthesis. To deal with the high salinity stress, stolon could store more energy by activating “carbohydrate/lipid transport” and “catabolism” pathways. The energy generated by “lipid metabolism” pathway might be beneficial to resist the low temperature stress. The upregulation of “cell cycle” pathway could inhibit cell growth, thus helping stolon conserve more energy against the high temperature stress. Our results here provide valuable references of candidate pathways and associated genes for studying mechanisms of harsh environmental adaptation and developing antifouling strategies in marine and coastal ecosystems.

海鞘，尤其是那些极具侵扰性的种类，是典型的附着生物，能够在沿海生态系统中造成显著的负面生态和经济影响。茎枝，某些独居海鞘所特有的结构，用以完成附着过程中的关键粘附步骤，对生物附着和侵扰过程中的环境压力具有极高的耐受性。然而，其背后的耐受机制尚处于未知状态。本研究中，我们运用定量蛋白质组学技术，同位素标记相对和绝对定量（iTRAQ），对高度侵扰性附着海鞘Ciona robusta茎枝在面对环境挑战（温度和盐度）时的分子响应进行了研究。在低盐度、高盐度、低温和高温压力条件下，分别鉴定出75、86、123和83种差异丰度蛋白。生物信息学分析揭示了在温度和盐度压力下起关键作用的通路，包括“细胞骨架”、“信号传导”和“翻译后修饰”，这些通路与茎枝结构稳定性、蛋白质合成及压力响应激活相关。在低盐度压力下，“细胞外基质”通路被发现通过调节细胞信号传导和蛋白质合成发挥至关重要的作用。为了应对高盐度压力，茎枝通过激活“碳水化合物/脂质运输”和“分解代谢”通路来储存更多的能量。由“脂质代谢”通路产生的能量可能有助于抵抗低温压力。上调“细胞周期”通路可以抑制细胞生长，从而帮助茎枝在高温压力下保存更多能量。本研究结果为研究恶劣环境适应机制以及开发海洋和沿海生态系统的防污策略提供了宝贵的候选通路和关联基因的参考。