Signal transduction in plants determines their successful adaptation to diverse stress factors. Our group employed suspension cells to study the phosphoinositide pathway, which is triggered by aluminium stress. We investigated about members of the PI-specific phospholipase C (PLC) family and evaluated their transcription profiles in Coffea arabica (Ca) suspension cells after 14days of culture when treated or not with 100μM AlCl3. The four CaPLC1-4 members showed changes in their transcript abundance upon AlCl3 treatment. The expression profiles of CaPLC1/2 exhibited a rapid and transitory increase in abundance. In contrast, CaPLC3 and CaPLC4 showed that transcript levels were up-regulated in short times (at 30s), while only CaPLC4 kept high levels and CaPLC3 was reduced to basal after 3h of treatment. CaPLC proteins were heterologously expressed, and CaPLC2 and CaPLC4 were tested for in vitro activity in the presence or absence of AlCl3 and compared to Arabidopsis PLC2 (AtPLC2). A crude extract was isolated from coffee cells. CaPLC2 showed a similar inhibition (30%) as in AtPLC2 and in the crude extract, while in CaPLC4, the activity was enhanced by AlCl3. Additionally, we visualized the yellow fluorescent protein PH domain of human PLCδ1 (YFP-PHPLCδ1) subcellular localization in cells that were treated or not with AlCl3. In non-treated cells, we observed a polar fluorescence signal towards the fused membrane. However, when cells were treated with AlCl3, these signals were disrupted. Finally, this is the first time that PLC activity has been shown to be stimulated in vitro by AlCl3.

中文翻译：

---

响应铝胁迫的阿拉伯咖啡中磷脂酶C的生化特征。

植物中的信号转导决定了它们对各种胁迫因素的成功适应。我们的小组利用悬浮细胞研究了铝应激触发的磷酸肌醇途径。我们调查了PI特异性磷脂酶C（PLC）家族的成员，并在用或不使用100μMAlCl3处理14天后评估了它们在阿拉伯咖啡（Ca）悬浮细胞中的转录谱。四个CaPLC1-4成员在AlCl3处理后显示其转录丰度变化。CaPLC1 / 2的表达谱显示出丰富的快速和短暂的增加。相反，CaPLC3和CaPLC4显示，转录水平在短时间内（30秒内）上调，而只有CaPLC4保持高水平，而CaPLC3在处理3小时后降至基础水平。CaPLC蛋白异源表达，在存在或不存在AlCl3的情况下测试CaPLC2和CaPLC4的体外活性，并与拟南芥PLC2（AtPLC2）进行比较。从咖啡细胞中分离出粗提物。CaPLC2表现出与AtPLC2和粗提物中相似的抑制作用（30％），而在CaPLC4中，AlCl3增强了活性。此外，我们可视化了人类PLCδ1（YFP-PHPLCδ1）亚细胞定位在未经AlCl3处理的细胞中的黄色荧光蛋白PH结构域。在未处理的细胞中，我们观察到朝向融合膜的极性荧光信号。但是，当用AlCl3处理细胞时，这些信号被破坏了。最终，这是首次显示AlCl3在体外刺激PLC活性。