苹果矮化砧木‘M9T337’一直采用压条及硬枝扦插繁殖，组培时难以生根，本团队发现，金属离子螯合剂EDTA能抑制‘M9T337’组培苗生根，并利用转录组和蛋白组分析发现EDTA能导致MdGSNOR1功能的降低，造成蛋白质亚硝基化修饰增加，首次发现了EDTA具有螯合金属离子以外的新生物学功能。本研究拟通过构建MdGSNOR1稳定转基因植株，解析EDTA调控MdGSNOR1的转录机制；利用蛋白质亚硝基化质谱手段，深入探索EDTA介导的亚硝基化修饰蛋白及其亚硝基化位点；利用基因定点突变及转基因技术对发生亚硝基化修饰的关键蛋白及其亚硝基化位点进行功能解析，揭示其调控不定根形成的分子机制；利用生物大分子互作、酵母双杂交等分子生物学技术，构建亚硝基化修饰蛋白的互作网络；通过以上研究系统解析EDTA介导蛋白质亚硝基化途径抑制组培苗生根的分子机制，为组培生根的理论和应用研究奠定基础。

Plant tissue culture plays an important role in the production of apple rootstocks especially in the rapid propagation and extensive application of the dwarfing rootstocks. M9T337 dwarfing rootstock has been propagated by layering and hardwood cutting, which is difficult in root formation by tissue culture. Our team has found that metal chelating agent EDTA can inhibit root formation of M9T337 dwarfing rootstock in the tissue culture, and EDTA can promote nitrosylation of proteinsby the transcriptome and proteome. Our study is aim to study EDTA-mediated nitrosylation pathway and further identify the protein and its nitrosylation site modified by the mass spectra and bioinformatics. By means of comparative genomics, the differences of nitrosylation pathways in the evolution of different apple varieties were explored. Moreover, site-directed mutagenesis, transgenic technology and cell biology were used to analyze the key proteins and their nitrosylation sites in order to reveal the molecular mechanism of regulating the formation of apple adventitious roots. Molecular biological techniques such as biomacromolecular interaction and yeast two hybrid system were used to establish the interaction network of nitrosylated modified proteins, and further comprehensively analyze the systematic mechanism of EDTA-mediated nitrosylation of proteins in inhibiting root formation of tissue culture seedlings. Information gained through this study will lay a solid foundation for theoretical and applied research on tissue culture rooting.