A small-RNA pathway that regulate male fertility under heat stress in grasses

与动物不同，植物在有性繁殖期间变得极其脆弱，因为它们经历了遗传减少(减数分裂)和大规模的发育和全基因组重新编程，以产生专门的单倍体配子(例如雄性精子细胞和雌性卵细胞)。由于植物的固位性，植物被认为进化出了应对机制，能够在这些关键时刻抵御环境温度的波动，然而，这种机制的分子细节还远不清楚。我们最近发现了一类新的小RNAs(Hphasi)，它与男性生殖细胞及其周围的体细胞中特有的Argavite蛋白一起作用，在热应激条件下调节男性的生育能力。我们也有各种证据表明，这条途径在草类中是保守的。因此，在这项建议中，我们建议使用玉米作为一个模式作物系统，通过使用各种实验方法(例如，)来确切地确定这种sRNA途径如何在环境约束下调节雄性育性。发育遗传学、生化和分子技术)，以揭示所涉及的各种成分和调节因素。我们预计，这项工作不仅将促进我们对谷类植物如何保护其雄性生殖系的基本理解，还将提供重要的技术诀窍，以设计新的谷类作物育种工具，使其更能适应气候变化带来的温度胁迫。

Unlike in animals, plants become extremely vulnerable during sexual reproduction as they undergo genetic reduction (meiosis) and large-scale developmental and whole-genome reprogramming to produce specialized haploid gametes (e.g. male sperm cells and female egg cells). Due to their sessile nature, plants are thought to have evolved coping mechanisms to be able to withstand fluctuations in ambient temperature during these critical times, however, the molecular details of such mechanisms are far from clear. We recently uncovered the presence of a novel class of small RNAs (Hphasi) acting with specific Argonaute proteins found exclusively in male germ cells and their surrounding somatic cells to regulate male fertility during heat stress conditions. We also have various lines of evidence suggesting that this pathway is conserved in the grasses. In this proposal, we therefore propose to use maize as a model crop system to determine exactly how this sRNA pathway regulates male fertility under environmental constrains, by using a variety of experimental approaches (eg. developmental genetics, biochemical, and molecular techniques) to uncover the various components and regulatory factors involved. We anticipate that this work will not only advance our basic understanding of how cereal plants safeguard their male germline but will also provide important know-how to engineer new breeding tools in cereal crops to make them more resilient to temperature stress brought on by climate change.