CSIR- National Botanical Research Institute, Rana Pratap Marg, Lucknow, 226001, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Plant Mol Biol. 2020 Aug;103(6):639-652. doi: 10.1007/s11103-020-01015-w. Epub 2020 May 19.
Pearl millet is a widely cultivated grain and forage crop in areas frequented with hot and dry weather, and high temperature. Being cultivated in arid and semi-arid regions, the crop often encounters intermittent water stress either at early stages of development or flowering stage or both. However, its asynchronous tillering behavior and fast growth rate helps recovering from drought stress at vegetative stages while there is no such reprieve under terminal stress (flowering through grain filling). At present, the molecular basis of terminal drought tolerance of certain pearl millet genotypes remains elusive. In this study, a comparative transcriptome analysis has been performed at both vegetative and flowering stages of a terminal drought tolerant genotype, PRLT2/89-33, subjected to drought stress. The gene expression profiling analysis showed that PRLT2/89-33 has an inherent ability to sense drought at both developmental stages. Gene Ontology (GO) and MapMan pathway analyses underlined that flavanoid pathway, lignin biosynthesis, phenyl propanoid pathway, pigment biosynthesis, and other secondary metabolite pathways were enriched in control and drought stressed PRLT2/89-33 at flowering stage than at the vegetative stage. To our knowledge, this is the first report of comparative transcriptome analysis under drought stress at two different developmental stages which can facilitate fastidious discovery of drought tolerant genes leading to improved yield in pearl millet and other related crops.
珍珠粟是一种广泛种植的粮食和饲料作物，适合在炎热和干燥天气以及高温地区种植。由于种植在干旱和半干旱地区，该作物在发育早期、开花期或两者都经常遇到间歇性水分胁迫。然而，其异步分蘖行为和快速生长速度有助于在营养生长阶段从干旱胁迫中恢复，而在终端胁迫（从开花到灌浆）下则没有这种缓解。目前，某些珍珠粟基因型对终端干旱耐受性的分子基础仍然难以捉摸。在这项研究中，对一个终端耐旱基因型 PRLT2/89-33 在营养生长和开花阶段进行了比较转录组分析，该基因型受到干旱胁迫的影响。基因表达谱分析表明，PRLT2/89-33 在两个发育阶段都具有感知干旱的内在能力。基因本体论（GO）和 MapMan 途径分析强调，在开花期，黄酮类途径、木质素生物合成、苯丙烷途径、色素生物合成和其他次生代谢途径在对照和干旱胁迫下的 PRLT2/89-33 中比在营养生长阶段更为丰富。据我们所知，这是首次在两个不同发育阶段对干旱胁迫下进行比较转录组分析的报道，这有助于快速发现耐旱基因，从而提高珍珠粟和其他相关作物的产量。
