The function of small RNAs in the nitrogen response

描述（申请人提供）：我们的长期目标是了解氮（N）信号如何控制植物的N-同化，生长和发育。确定参与调节氮同化的关键组分为提高植物的氮利用效率或改变种子的氨基酸含量提供了机会，这些都是健康，农业和人类营养的重要问题。本提案中的实验应该提供深入了解植物如何在分子水平上感知和响应N，特别是通过microRNA（miRNAs）和其他小RNA（sRNAs）对基因表达的转录后控制。鉴定参与响应于N处理的基因网络调节的sRNA可以鉴定可能通过特异性sRNA的异位表达或错误表达而改变以优化N同化的机制。现在已经清楚，miRNA是植物和动物中调控网络的关键组成部分，但它们在介导靶基因的N-反应中的作用尚未得到解决。我们建议：（1）鉴定其表达受N-处理调控的miRNA和其他sRNA;（2）鉴定由这些N-调节的sRNA控制的基因网络;（3）了解sRNA在介导网络中靶基因的N-响应中的功能作用。我们的实验方法将是从瞬时处理的植物中分离sRNA，使用454技术对sRNA进行测序，并将这些样品中的转录本频率与模拟处理植物样品中的转录本频率进行比较。我们将把已知的和新的sRNA：RNA相互作用纳入我们现有的基因网络模型，以确定由N-响应sRNA控制的子网络。我们将使用反向遗传学和基因组学方法来评估特定sRNA在植物对N处理的反应中的作用。与Coruzzi博士的小组合作进行的该项目中生物信息学和基因组方法的功能研究相结合，将大大加强Gutiirrez博士在智利和南美洲的研究能力。这些领域的专业知识对于后基因组时代的竞争性研究计划至关重要，这是智利和南美洲研究的一个欠发达领域。大部分研究将在智利的P. Universidad Catslica de Chile与Rodrigo Gutiirrez博士合作进行，作为NIH授予格洛丽亚M博士的#2R01 GM 032877 - 21的扩展。科鲁齐这一提议将为植物在分子水平上如何感知和响应氮提供深入了解。确定参与调节氮同化的关键组分为提高植物的氮利用效率或改变种子的氨基酸含量提供了机会，这些都是健康，农业和人类营养的重要问题。

DESCRIPTION (provided by applicant): Our long-term goal is to understand how nitrogen (N) signaling controls plant N-assimilation, growth and development. Identifying key components involved in regulating N-assimilation offers opportunities for improving N-use efficiency in plants or modifying the amino acid content of seeds, which are important issues for health, agriculture and human nutrition. The experiments in this proposal should provide insight into how plants sense and respond to N at the molecular level, specifically through the post transcriptional control of gene expression by microRNAs (miRNAs) and other small RNAs (sRNAs). Identifying the sRNAs involved in regulation of gene networks in response to N-treatment could identify mechanisms which may be altered to optimize N-assimilation via the ectopic expression or misexpression of specific sRNAs. It is now clear that miRNAs are key components of regulatory networks in plants and animals, but their role in mediating the N- response of target genes has not been addressed. We propose to (1) Identify the miRNAs and other sRNAs whose expression is regulated by N-treatments; (2) Identify the gene networks that are controlled by these N- regulated sRNAs; and (3) Understand the functional role of sRNAs in mediating the N-response of target genes in the network. Our experimental approach will be to isolate sRNAs from plants treated transiently with inorganic N sources, sequence the sRNAs using 454 technology, and compare the frequency of transcripts in these samples with the frequency in samples from mock-treated plants. We will incorporate known and novel sRNA:RNA interactions into our existing gene network models to identify subnetworks that are controlled by N- responsive sRNAs. We will use reverse genetic and genomic approaches to evaluate the role of specific sRNAs in the plant response to N-treatments. The combination of bioinformatic and genomic approaches for functional studies in this project performed in collaboration with Dr. Coruzzi's group, will greatly strengthen the research capability of Dr. Gutiirrez research program in Chile and South America. Expertise in these areas is essential for competitive research programs in the post-genomic era, and it is an underdeveloped area of research in Chile and South America. Most of the research will be carried out in Chile at P. Universidad Catslica de Chile in collaboration with Dr. Rodrigo Gutiirrez, as an extension of NIH grant #2R01GM032877- 21 to Dr. Gloria M. Coruzzi. This proposal should provide insight into how plants sense and respond to nitrogen at the molecular level. Identifying key components involved in regulating nitrogen assimilation offers opportunities for improving nitrogen-use efficiency in plants or modifying the amino acid content of seeds, which are important issues for health, agriculture and human nutrition.