Roles of meiotic-stage non-coding RNAs in maize anther development

花粉的产生和植物育性的调节对农业是至关重要的。杂交玉米和其他谷物极大地提高了世界粮食产量。这个项目将研究支持花药(开花植物中产生花粉的器官)中花粉发育的RNA的功能。该项目将利用植物基因组学和发育生物学来确定小RNA的生物学作用，以及利用它们实现花药功能的蛋白质。这些RNA是强健的男性生育能力所必需的：在缺乏小RNA的情况下，在正常温度下，发育失败，导致男性不育。在较低的温度下，可以挽救生育能力，将环境条件与这些小RNA的作用联系起来。该项目将重点放在玉米上，因为它是拟议实验的最佳系统；此外，雄性可育性是生产杂交玉米种子的关键。该项目的成果可能包括改善对牧草作物雄性育性的控制。该项目的更广泛影响包括对学生进行植物和RNA生物学方面的培训。该项目将专门专注于24-NT阶段性次级siRNAs，即“24-nt phasiRNAs”，它在减数分裂阶段的花药中高度丰富。该项目将对功能丧失的敲除基因的表型和分子遗传分析进行表征，其中包括Dector-like 5(Dcl5)基因，初步数据表明该基因是男性不育的。本项目要解决的问题包括哪些基本的Helix-Loop-Helix转录因子功能激活24-NT phasiRNAs的转录？核心生物发生蛋白DCL5是如何发挥作用的？在缺乏DCL5的情况下，不育表型的确切性质是什么？在玉米的其他背景中是否存在dcl5条件表型的遗传修饰物？装载24-ntphasiRNAs以发挥其功能的关键催化ArgAerte蛋白是什么？该奖项是由分子和细胞生物科学部门的遗传机制集群和综合组织系统部门的植物基因组研究计划共同资助的。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Pollen production and regulation of plant fertility are essential to agriculture. Hybrid corn and other grains have significantly boosted world food production. This project will investigate the functions of RNAs that support pollen development in anthers (the organs that make pollen in flowering plants). The project will utilize plant genomics and developmental biology to determine the biological roles of small RNAs and the proteins that utilize them for anther functions. These RNAs are required for robust male fertility: in the absence of the small RNAs, at normal temperatures, development fails, yielding male sterility. Fertility can be rescued under lower temperatures, linking environmental conditions to the role of these small RNAs. The project focuses on maize because it is an optimal system for the proposed experiments; plus, male fertility is key to the production of hybrid corn seed. Outcomes of this project could include improved control of male fertility in grass crops. Broader impacts of the project include training of students in plant and RNA biology. The project will focus specifically on the class of 24-nt phased, secondary siRNAs, known as “24-nt phasiRNAs” that are highly enriched in meiotic-stage anthers. The project will characterize phenotypes and molecular genetic analysis of loss-of-function knock-outs including the Dicer-like5 (Dcl5) gene, for which the preliminary data demonstrate male sterility. The questions to be addressed by this project include which basic Helix-Loop-Helix transcription factors function to activate transcription of the 24-nt phasiRNAs? How does the core biogenesis protein DCL5 function, and what is the exact nature of the phenotype of sterility in its absence? Are there genetic modifiers of the dcl5 conditional phenotype in other backgrounds of maize? What are the key catalytic Argonaute proteins that load the 24-nt phasiRNAs for their function? And what are the target RNAs with which the phasiRNA-loaded Argonaute proteins interact?This award was co-funded by the Genetic Mechanisms Cluster in the Division of Molecular and Cellular Biosciences and the Plant Genome Research Program in the Division of Integrative Organismal Systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.