藜磷酸肌醇5-磷酸酶基因(CaP5P)的表达分析和胁迫响应检测

植物通过多种信号途径感知外界环境变化，从而引发一系列的信号级联反应，其中磷脂信号途径起着重要的作用。本研究从藜盐胁迫差减文库中获得了一个EST05序列，利用RT-PCR检测了其在非生物胁迫下表达趋势，显示EST05序列在非生物胁迫下的表达有升高。随后利用RACE技术获得其全长编码序列，测序结果显示其与蓖麻(Ricinus communis) 的磷酸肌醇5-磷酸酶基因(P5P)的同源性达56%，遂将其命名为CaP5P。最后过量表达CaP5P在拟南芥中初步验证了功能，转基因植株表现对盐胁迫耐受性降低的趋势，呈现负调控的特征。本研究对磷酸肌醇5-磷酸酶基因功能的初步研究为磷脂信号途径中负调控组分的分析提供了参考依据。

Expression Analysis and Stress Response Detection of the Phosphoinositide 5-phosphatase gene (CaP5P) in Chenopodium album

Plants sense changes in the external environment through a number of signaling pathways, then give rise to a series of signaling cascades, among these, phospholipid signaling pathway plays an important role. We obtained an EST05 sequence from the suppression subtractive library under salt stress in Chenopodium album. The expression changes under different abiotic stresses were analyzed by RT-PCR, the results showed that the expression level of EST05 increased under the abiotic stress. Then, the ORF sequence was obtained by 3′- and 5′-RACE method. Sequence analysis showed that it is highly homologous with the phosphoinositide 5-phosphatase gene in Ricinus communis, which was then named as CaP5P. Finally, CaP5P was overexpressed in Arabidopsis thaliana to verify its function. Transgenic Arabidopsis showed reduced tolerance to salt stress in seed germination and seedling growth, suggesting that CaP5P performed as a negative regulatory factor under stress. The preliminary result is expected to provide the reference for negative regulation component in phospholipid signaling pathway.