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

花粉的产生和植物肥力的调控对农业至关重要。杂交玉米和其他谷物显著提高了世界粮食产量。该项目将研究支持花粉在花药（开花植物中产生花粉的器官）中发育的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：在正常温度下，缺乏小rna，发育失败，导致男性不育。在较低的温度下可以恢复生育能力，将环境条件与这些小rna的作用联系起来。该项目以玉米为重点，因为它是拟议实验的最佳系统；另外，雄性的生育能力是杂交玉米种子生产的关键。该项目的成果可能包括改善对牧草雄性生育力的控制。该项目更广泛的影响包括培养学生在植物和RNA生物学方面的知识。该项目将特别关注24-nt阶段的次级sirna，即在减数分裂阶段花药中高度富集的“24-nt阶段sirna”。该项目将描述包括dicer样5 （Dcl5）基因在内的功能缺失基因敲除的表型和分子遗传分析，初步数据表明该基因具有男性不育性。该项目需要解决的问题包括哪些基本的Helix-Loop-Helix转录因子可以激活24-nt phasiRNAs的转录？核心生物发生蛋白DCL5是如何起作用的，在缺乏它的情况下，不育表型的确切性质是什么？在其他背景的玉米中是否存在dcl5条件表型的遗传修饰因子？装载24-nt相rna以发挥其功能的关键催化Argonaute蛋白是什么？装载相rna的Argonaute蛋白与哪些目标rna相互作用？该奖项由分子和细胞生物科学部的遗传机制集群和综合有机系统部的植物基因组研究计划共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.