Asian Natural Environmental Science Center (ANESC), the University of Tokyo, Nishitokyo-shi, Tokyo, Japan.
Hokkaido University, Hokkaido, Japan.
PLoS One. 2018 Apr 13;13(4):e0195908. doi: 10.1371/journal.pone.0195908. eCollection 2018.
Pearl millet is a cereal crop known for its high tolerance to drought, heat and salinity stresses as well as for its nutritional quality. The molecular mechanism of drought tolerance in pearl millet is unknown. Here we attempted to unravel the molecular basis of drought tolerance in two pearl millet inbred lines, ICMB 843 and ICMB 863 using RNA sequencing. Under greenhouse condition, ICMB 843 was found to be more tolerant to drought than ICMB 863. We sequenced the root transcriptome from both lines under control and drought conditions using an Illumina Hi-Seq platform, generating 139.1 million reads. Mapping of sequenced reads against the foxtail millet genome, which has been relatively well-annotated, led to the identification of several differentially expressed genes under drought stress. Total of 6799 and 1253 differentially expressed genes were found in ICMB 843 and ICMB 863, respectively. Pathway and gene function analysis by KEGG online tool revealed that the drought response in pearl millet is mainly regulated by pathways related to photosynthesis, plant hormone signal transduction and mitogen-activated protein kinase signaling. The changes in expression of drought-responsive genes determined by RNA sequencing were confirmed by reverse-transcription PCR for 7 genes. These results are a first step to understanding the molecular mechanisms of drought tolerance in pearl millet and lay a foundation for its genetic improvement.
珍珠粟是一种谷物作物，以其对干旱、高温和盐胁迫的高度耐受性以及其营养价值而闻名。珍珠粟耐旱的分子机制尚不清楚。在这里，我们试图使用 RNA 测序来揭示两个珍珠粟自交系 ICMB 843 和 ICMB 863 的耐旱分子基础。在温室条件下，发现 ICMB 843 比 ICMB 863 更能耐受干旱。我们使用 Illumina Hi-Seq 平台对这两个系在对照和干旱条件下的根转录组进行了测序，共产生了 1.391 亿个reads。将测序reads 映射到相对注释良好的谷子基因组上，鉴定出了在干旱胁迫下几个差异表达的基因。在 ICMB 843 和 ICMB 863 中分别发现了 6799 和 1253 个差异表达基因。KEGG 在线工具的通路和基因功能分析表明，珍珠粟的干旱反应主要由与光合作用、植物激素信号转导和丝裂原活化蛋白激酶信号转导相关的通路调控。通过 RNA 测序确定的耐旱相关基因的表达变化通过 RT-PCR 对 7 个基因进行了验证。这些结果是了解珍珠粟耐旱分子机制的第一步，为其遗传改良奠定了基础。
