Abstract：
Drought stress is a common adverse environment that plants encounter, and many drought-tolerant genes have been characterized. The gene regulatory network (GRN) is important in revealing the drought tolerance mechanism. Here, to investigate the regulatory mechanism of Shanxin poplar (Populus davidiana × P. bolleana) responding to drought stress, a three-layered GRN was built, and the regulatory relationship between genes in the GRN were predicted from expression correlation using a partial correlation coefficient-based algorithm. The GRN contains 1869 regulatory relationships, and includes 11 and 19 transcription factors (TFs) in the first and second layers, respectively, and 158 structural genes in the bottom layers involved in eight enriched biological processes. ChIP-PCR and qRT-PCR based on transient transformation were performed to validate the reliability of the GRN. About 88.0% of predicted interactions between the first and second layers, and 82.0% of predicted interactions between the second and third layers were correct, suggesting that the GRN is reliable. Six TFs were randomly selected from the top layer for characterizing their function in drought, and all of these TFs can confer drought tolerance. The important biological processes related to drought tolerance were identified, including \"response to jasmonic acid\", \"response to oxidative stress\", and \"response to osmotic stress\". In this GRN, PdbERF3 is predicted to play an important role in drought tolerance. Our data revealed the key regulators, TF-DNA interactions, and the main biological processes involved in adaption of drought stress in Shanxin poplar.
摘要：
干旱胁迫是植物常见的不利环境,许多耐旱基因已经被表征。基因调控网络(GRN)在揭示抗旱机制方面具有重要意义。这里,为探讨山心杨树(Populusdavidiana×P.bolleana)对干旱胁迫的响应机制,建立了一个三层的GRN，并使用基于偏相关系数的算法从表达相关性预测GRN中基因之间的调控关系。GRN包含1869个监管关系，并且在第一层和第二层中包括11个和19个转录因子（TF），分别,底层的158个结构基因参与了八个富集的生物过程。进行基于瞬时转化的ChIP-PCR和qRT-PCR以验证GRN的可靠性。第一层和第二层之间约88.0%的预测相互作用，第二层和第三层之间的预测相互作用的82.0%是正确的，这表明GRN是可靠的。从顶层随机选择六个TF来表征它们在干旱中的功能，所有这些TFs都可以赋予耐旱性。确定了与耐旱性有关的重要生物学过程，包括“对茉莉酸的反应”，“对氧化应激的反应”，和“对渗透胁迫的反应”。在这个GRN中，预计PdbERF3在耐旱性中起重要作用。我们的数据揭示了关键的监管机构，TF-DNA相互作用，山心杨树适应干旱胁迫的主要生物学过程。
