假俭草多分蘖基因MTN1的鉴定及功能分析

假俭草是起源于我国优良的暖季型草坪草。然而，假俭草分蘖较少导致种子产量低和建植困难，且相关分子机制不清楚，成为制约其广泛推广应用的瓶颈。前期，利用自主研发的冷等离子体诱变专利技术创制了一个假俭草多分蘖突变体mtn1，分析并克隆了候选功能基因EoMTN1，EoMTN1基因的突变可能影响了突变体中生长素的极性运输。本项目拟进一步鉴定EoMTN1基因的功能并分析其作用机制：采用互补、过表达和基因沉默的转基因方法验证EoMTN1基因的功能；利用亚细胞定位、GUS染色、qRT-PCR等方法分析EoMTN1基因的表达特征，通过同位素示踪、DR5::GUS生长素报告系统、酵母异源表达系统等分析EoMTN1蛋白的生长素极性运输功能；采用转录组测序技术探析EoMTN1基因的调控网络。本研究不仅可以为培育多分蘖假俭草品种提供理论依据和现实育种材料，也可以拓展其他草坪草分蘖性状遗传改良的技术途径。

Centipedegrass [Eremochloa ophiuroides (Munro) Hack.] is an excellent warm-season turfgrass originated in China. Tillering is a key breeding trait that affects establishment rate, seed yields and biomass of centipedegrass. However, low tillering resulted in low seed yields and difficulty establishment of centipedegrass, and the related molecular mechanisms were still unknown. These are limiting factors for its further application. A more tillering number (mtn1) mutant with stable inheritance in centipedegrass was obtained by a new cold plasma mutation breeding technology, invented by our research team. We analyzed and cloned the candidate gene EoMTN1 using the whole-genome resequencing with bulked segregation analysis (BSA). Mutation of EoMTN1 gene may affect polar transport of auxin in mtn1 mutant. In this research, we intend to identify the function of EoMTN1 gene and investigate the molecular mechanisms of this gene in regulating tiller development of centipedegrass. We will firstly identify the function of EoMTN1 gene by complementation, overexpression and silencing approaches. Then, we will analyze the expression pattern of EoMTN1 gene via subcellular position, GUS staining and qRT-PCR analysis. We will also analyze the auxin transport function of EoMTN1 protein through isotope tracer technique, DR5::GUS auxin reporter system and yeast heterologous expression system. Finally, we will explore the network regulated by EoMTN1 gene using RNA-seq and bioinformatic analysis. The implementation of this research will not only provide theoretical basis and practical materials for breeding high-tillering centipedegrass, but also expand approaches for the genetic improvement of tillering phenotype in other turfgrasses.