Regeneration of Solanum tuberosum Plants from Protoplasts Induces Widespread Genome Instability
Regeneration of Solanum tuberosum Plants from Protoplasts Induces Widespread Genome Instability
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DOI：
10.1104/pp.18.00906
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发表时间：
2019-05-01
期刊：
影响因子：
7.4
通讯作者：
Comai, Luca
中科院分区：
文献类型：
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作者：
Fossi, Michelle;Amundson, Kirk;Comai, Luca
可再生原生质体中的非转基因基因基因组编辑，植物细胞没有细胞壁，可以彻底改变作物改良，因为它降低了监管和技术复杂性。然而，已知植物组织培养会产生频繁的不想要的变异，称为体细胞克隆变异。为了评估大规模基因组不稳定性对这种现象的贡献，我们通过比较Illumina读取深度分析了从原生质体或茎外植体再生的马铃薯（Solanum tuberosum）的拷贝数变化。而对照组的8株植物，已繁殖的插条显示没有变化，所有15个原生质体再生测试的影响，非整倍性或结构染色体的变化。某些染色体显示节段缺失和重复，从一个到多个。对同一植株的不同叶片进行再生，发现三个再生体存在差异，表明不稳定性经常持续存在。相比之下，33个再生体茎外植体用于农杆菌介导的转化显示频率较低，但仍然相当大（18%）的大规模拷贝数的变化。某些不稳定模式的重复表明特定基因组位点的易感性更高。这些结果表明，组织培养，取决于所使用的协议，可以诱导基因组的不稳定性，导致大规模的变化，可能会损害最终的植物表型。
Nontransgenic genome editing in regenerable protoplasts, plant cells free of their cell wall, could revolutionize crop improvement because it reduces regulatory and technical complexity. However, plant tissue culture is known to engender frequent unwanted variation, termed somaclonal variation. To evaluate the contribution of large-scale genome instability to this phenomenon, we analyzed potatoes (Solanum tuberosum) regenerated from either protoplasts or stem explants for copy number changes by comparison of Illumina read depth. Whereas a control set of eight plants that had been propagated by cuttings displayed no changes, all 15 protoplast regenerants tested were affected by aneuploidy or structural chromosomal changes. Certain chromosomes displayed segmental deletions and duplications ranging from one to many. Resampling different leaves of the same plant found differences in three regenerants, indicating frequent persistence of instability. By comparison, 33 regenerants from stem explants used for Agrobacterium-mediated transformation displayed less frequent but still considerable (18%) large-scale copy number changes. Repetition of certain instability patterns suggested greater susceptibility in specific genomic sites. These results indicate that tissue culture, depending on the protocol used, can induce genomic instability resulting in large-scale changes likely to compromise final plant phenotype.