StDRO1基因参与马铃薯根系形成的细胞基础及分子调控机制研究

Root is the most important nutrient and water uptake organ of crops; it is also the one of the most difficult plant organs to study. Potato has shallow root system, relatively sensitive to the drought, while the deeper root system could enhance the drought tolerance. Therefore, revealing the mechanism of the deeper root establishment and development of drought tolerant potato germplasms, is the fundamental step to improve deep lay soil water utilization efficiency, relieve the yield reduction caused by the drought stress. DRO1 has shown great potential on regulate the deeper rooting as well as the drought tolerance in rice. The homology of DRO1 in potato has been identified as StDRO1. however, the regulatory mechanism of StDRO1 in potato root development is not fully understand. In this study, to reveal the the cellular and molecular regulatory mechanisms of StDRO1 gene in potato deeper root formation, the CRISPR/Cas system was designed to knockout StDRO1 from potato germplasms with the significant root architecture variation. Under the drought stress, the morphological characteristics of root tip, elongation zone cell as well as the sub-cellular structure of crown cell from the wild type, StDRO1 knockout lines, StDRO1 overexpress as well as knockout complementation lines will be analyzed. The regulatory network of StDRO1 will be further characterized by transcriptomics and proteomic association analysis. The results from this study will facilitate the further understanding of potato root formation, breeding of the drought tolerant germplasms with the deeper root system, and developing the high efficient water saving cultivation technique. Furthermore, the results will contribute greatly to the sustainable development of potato industry in the arid and semi arid potato planting regions.

根系是作物最主要的营养与水分汲取器官，但是也是最难研究的植物组织。研究发现通过DRO1参与调控的较深的根系有利于水稻对干旱的耐受性。StDRO1为马铃薯中与水稻DRO1同源的基因，但有关该基因参与马铃薯深根形成的细胞学基础及分子调控机制尚未见报道。本项目以根系差异明显的2份四倍体马铃薯栽培种为材料，通过转基因与CRISPR/Cas技术获得StDRO1过表达和敲除系，分析干旱条件下野生型、敲除系及过表达系的根系形态、伸长区细胞形态及数量、根冠细胞的超微结构，及根系发育形成相关基因在转录和翻译水平的差异，探明干旱胁迫下StDRO1参与马铃薯深根形成的细胞学基础及分子调控机制。项目的实施对阐明马铃薯根系的形成机制、深根耐旱机理的解析、耐旱新种质的创制及干旱半干旱地区马铃薯产业的可持续发展均具有重要的理论与实践指导意义。

根系是作物最主要的营养与水分汲取器官，但是也是最难研究的植物组织。在水稻、拟南芥和小麦等植物中的研究表明，DRO1在调控根系生长发育中中起着重要作用，进而影响其抗旱性。StDRO1为马铃薯中与水稻DRO1同源的基因。经过四年的研究，我们在马铃薯StDRO1的基因功能研究和马铃薯深根耐旱机理发掘中取得了以下研究结果：第一，本研究通过一系列研究证明了马铃薯StDRO1参与调控根系生长发育和抗旱性。第二，本研究利用一百多份马铃薯材料，对StDRO1的进行了基因多态性分析，鉴定出了12个SNP位点。与根系性状的关联分析表明，其中6个位点与多个根系性状显著关联。第三，本研究通过甘露醇模拟干旱胁迫，对C119（深根，抗旱）和C16（非深根，不抗旱）品系进行不同时间处理并采样后，进行了转录组测序，利用生物信息学数据分析方法，构建了与抗逆生理性状相关联的权重基因共表达网络，从中发掘出了十几个潜在的马铃薯深根抗旱基因。第四，我们通过基因家族分析，筛选出了StDRO1所属的StIGT基因家族的所有成员，并发现除StDRO1外，还有多个家族成员响应干旱胁迫。这些研究结果为我们进一步揭示马铃薯StIGT家族成员的功能提供依据，也为进一步深入解析马铃薯耐旱分子机制提和马铃薯耐旱种质创新提供了理论基础。