Regulation of the male germline in cereal crops by somatic companion cells

像动物一样，大多数二倍体植物在经历遗传减少（减数分裂）后进行有性繁殖，以分别在雄性和雌性性器官中产生特化的单倍体配子（即精子细胞和卵细胞）。然而，植物在成年后期从二倍体体细胞组织建立单倍体有性谱系（或生殖系）的过程还不清楚，但被认为涉及大规模的发育和全基因组重编程。本建议的重点是揭示这一进程所涉及的一些机制。我们有证据表明，新的小RNA结合Argonaute蛋白（AGO），特别是在男性生殖器官的谷物和其相关类的小非编码RNA分子控制男性生殖系的发展。有趣的是，这些AGO在男性生殖细胞和精子细胞周围的体细胞中表达，但这些AGO中的缺陷或突变会导致男性不育。在本提案中，我们将使用各种方法和实验技术（例如，发育遗传学、生物化学、计算和分子生物学），以确定体细胞伴侣细胞如何使用两种重要的模式作物植物（玉米和小麦）调节雄性生殖系的命运。我们预计，这项工作不仅将推进我们对植物如何建立雄性生殖系的基本理解，而且还将提供一种新的策略，以设计具有重要农业意义的谷类作物的新育种工具。

Like animals, most diploid plants reproduce sexually after going through genetic reduction (meiosis) to produce specialized haploid gametes (i.e. sperm cells and egg cells) within the male and female sex organs, respectively. However, the process by which plants establish haploid sexual lineages (or germlines) from diploid somatic tissues late in adult life is not yet understood, but is thought to involve large-scale developmental and whole-genome reprogramming. This proposal focuses on uncovering some of the mechanisms involved in this process. We have evidence that novel small-RNA binding Argonaute proteins (AGOs) specifically found in male reproductive organs of cereals and their associated class of small non-coding RNA molecules control the development of the male germline. Intriguingly, these AGOs are expressed in somatic cells surrounding the male germline and sperm cells, yet defects or mutations in these AGOs causes male sterility. In this proposal, we will use various approaches and experimental techniques (eg. developmental genetics, biochemistry, computational and molecular biology) to determine exactly how somatic companion cells regulate the fate of the male germline using two important model crop plants: maize and wheat. We anticipate that this work will not only advance our basic understanding of how plants set their male germline, but will also provide a novel strategy to engineer new breeding tools in agronomically important cereal crops.