Potato is the third most important food crop, but cultivation is challenged by numerous diseases and adverse abiotic conditions. To combat diseases, frequent fungicide application is common. Knocking out susceptibility genes by genome editing could be a durable option to increase resistance. DMR6 has been described as a susceptibility gene in several crops, based on data that indicates increased resistance upon interruption of the gene function. In potato, Stdmr6-1 mutants have been described to have increased resistance against the late blight pathogen Phytophthora infestans in controlled conditions. Here, we present field evaluations of CRISPR/Cas9 mutants, in a location with a complex population of P. infestans, during four consecutive years that indicate increased resistance to late blight without any trade-off in terms of yield penalty or tuber quality. Furthermore, studies from potato tubers from the field trials indicated increased resistance to common scab, and the mutant lines exhibit increased resistance to early blight pathogen Alternaria solani in controlled conditions. Early blight and common scab are problematic targets in potato resistance breeding, as resistance genes are very scarce. The described broad-spectrum resistance of Stdmr6-1 mutants may further extend to some abiotic stress conditions. In controlled experiments of either drought simulation or salinity, Stdmr6-1 mutant plants are less affected than the background cultivar. Together, these results demonstrate the prospect of the Stdmr6-1 mutants as a useful tool in future sustainable potato cultivation without any apparent trade-offs.

中文翻译：

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马铃薯 StDMR6-1 的 CRISPR/Cas9 基因组编辑可减少植物受不同胁迫条件的影响

马铃薯是第三重要的粮食作物，但种植面临众多疾病和不利的非生物条件的挑战。为了对抗疾病，频繁使用杀菌剂是很常见的。通过基因组编辑敲除易感基因可能是增加抵抗力的持久选择。 DMR6 已被描述为多种作物的易感基因，数据表明基因功能中断后抗性会增加。在马铃薯中，Stdmr6-1 突变体被描述在受控条件下对晚疫病病原体致病疫霉具有增强的抗性。在这里，我们在具有复杂的致病疫霉种群的地区连续四年对 CRISPR/Cas9 突变体进行了现场评估，结果表明对晚疫病的抗性有所增强，而在产量损失或块茎质量方面没有任何权衡。此外，田间试验的马铃薯块茎研究表明，对普通赤霉病的抗性增强，并且突变株系在受控条件下对早疫病病原体立格孢菌表现出增强的抗性。早疫病和赤霉病是马铃薯抗性育种中存在问题的目标，因为抗性基因非常稀缺。所描述的 Stdmr6-1 突变体的广谱抗性可能进一步扩展到一些非生物胁迫条件。在干旱模拟或盐度的对照实验中，Stdmr6-1 突变体植物比背景品种受到的影响更小。总之，这些结果证明了 Stdmr6-1 突变体作为未来可持续马铃薯种植的有用工具的前景，而无需任何明显的权衡。