Key message

Metabolic pathway gene editing in tetraploid potato enhanced resistance to late blight. Multiallelic mutation correction of a caffeoyl-CoA O-methyltransferase gene increased accumulation of resistance metabolites in Russet Burbank potato.

Abstract

Late blight of potato is a devastating disease worldwide and requires weekly applications of fungicides to manage. Genetic improvement is the best option, but the self-incompatibility and inter-specific incompatibility makes potato breeding very challenging. Immune receptor gene stacking has increased resistance, but its durability is limited. Quantitative resistance is durable, and it mainly involves secondary cell wall thickening due to several metabolites and their conjugates. Deleterious mutations in biosynthetic genes can hinder resistance metabolite biosynthesis. Here a probable resistance role of the StCCoAOMT gene was first confirmed by an in-planta transient overexpression of the functional StCCoAOMT allele in late blight susceptible Russet Burbank (RB) genotype. Following this, a precise single nucleotide polymorphism (SNP) mutation correction of the StCCoAOMT gene in RB potato was carried out using CRISPR-Cas9 mediated homology directed repair (HDR). The StCCoAOMT gene editing increased the transcript abundance of downstream biosynthetic resistance genes. Following pathogen inoculation, several phenylpropanoid pathway genes were highly expressed in the edited RB plants, as compared to the non-edited. The disease severity (fold change = 3.76) and pathogen biomass in inoculated stems of gene-edited RB significantly reduced (FC = 21.14), relative to non-edited control. The metabolic profiling revealed a significant increase in the accumulation of resistance-related metabolites in StCCoAOMT edited RB plants. Most of these metabolites are involved in suberization and lignification. The StCCoAOMT gene, if mutated, can be edited in other potato cultivars to enhance resistance to late blight, provided it is associated with other functional genes in the metabolic pathway network.

中文翻译：

---

Russet Burbank马铃薯品种中的咖啡酰辅酶A O -甲基转移酶基因SNP替代通过细胞壁强化增强晚疫病抗性

关键信息

四倍体马铃薯代谢途径基因编辑增强了对晚疫病的抗性。咖啡酰-CoA O -甲基转移酶基因的多等位基因突变校正增加了Russet Burbank马铃薯抗性代谢物的积累。

抽象的

马铃薯晚疫病在世界范围内是一种毁灭性的疾病，需要每周使用杀菌剂来管理。遗传改良是最好的选择，但自交不亲和和种间不亲和使马铃薯育种极具挑战性。免疫受体基因堆叠增加了抵抗力，但其持久性有限。定量抗性是持久的，它主要涉及由于几种代谢物及其结合物导致的次生细胞壁增厚。生物合成基因中的有害突变会阻碍抗性代谢物的生物合成。在这里， StCCoAOMT基因可能的抗性作用首先通过功能性StCCoAOMT的植物内瞬时过表达得到证实晚疫病易感 Russet Burbank (RB) 基因型中的等位基因。在此之后，使用 CRISPR-Cas9 介导的同源定向修复 (HDR) 对 RB 马铃薯中的StCCoAOMT基因进行精确的单核苷酸多态性 (SNP) 突变校正。StCCoAOMT基因编辑增加了下游生物合成抗性基因的转录本丰度。在病原体接种后，与未编辑的相比，编辑后的 ​​RB 植物中高度表达了几种苯丙烷途径基因。相对于未编辑的对照，基因编辑的 RB 的接种茎中的疾病严重程度（倍数变化 = 3.76）和病原体生物量显着降低（FC = 21.14）。代谢谱显示抗性相关代谢物的积累显着增加StCCoAOMT编辑了 RB 植物。大多数这些代谢物都参与了木脂化和木质化。如果StCCoAOMT基因发生突变，则可以在其他马铃薯品种中进行编辑以增强对晚疫病的抗性，前提是它与代谢途径网络中的其他功能基因相关。