High-yielding and stress resistant crops are essential to ensure future food supply. Barley is an important crop to feed livestock and to produce malt, but the annual yield is threatened by pathogen infections. Pathogens can trigger an altered sugar partitioning in the host plant, that possibly leads to an advantage for the pathogen. Hampering these processes represents a promising strategy to potentially increase resistance. We analyzed the response of the barley monosaccharide transporter HvSTP13 towards biotic stress and its potential use for plant protection. The expression of HvSTP13 increased upon bacterial and fungal PAMP application, suggesting a PAMP-triggered signaling that converged on the transcriptional induction of the gene. Promoter studies indicate a region that is likely targeted by transcription factors downstream of PAMP-triggered immunity pathways. We confirmed that the non-functional HvSTP13GR variant confers resistance against an economically relevant biotrophic rust fungus, in barley. In addition, we established targeted CRISPR/Cas9 cytosine base editing in barley protoplasts to generate alternative HvSTP13 mutants and characterized the sugar transport activity and subcellular localization of the proteins. These mutants represent promising variants for future resistance analysis. Our experimental setup provides basal prerequisites to further decode the role of HvSTP13 in response to biological stress. Moreover, in line with other studies, our experiments indicate that the alteration of sugar partitioning pathways, in a host pathogen interaction, is a promising approach to achieve broad and durable resistance in plants.

中文翻译：

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大麦 HvSTP13GR 突变体触发对生物营养真菌的抗性

高产和抗逆作物对于确保未来的粮食供应至关重要。大麦是饲养牲畜和生产麦芽的重要作物，但年产量受到病原体感染的威胁。病原体可以触发宿主植物中糖分配的改变，这可能会导致病原体的优势。阻碍这些过程代表了一种潜在增加抵抗力的有前途的策略。我们分析了大麦单糖转运蛋白HvSTP13对生物胁迫的反应及其在植物保护中的潜在用途。HvSTP13的表达在细菌和真菌 PAMP 应用后增加，表明 PAMP 触发的信号传导收敛于基因的转录诱导。启动子研究表明，PAMP 触发的免疫通路下游的转录因子可能靶向一个区域。我们证实，非功能性 HvSTP13GR 变体对大麦中的经济相关生物营养锈菌具有抗性。此外，我们在大麦原生质体中建立了靶向 CRISPR/Cas9 胞嘧啶碱基编辑以生成替代的HvSTP13突变体，并表征了蛋白质的糖转运活性和亚细胞定位。这些突变体代表了未来抗性分析的有希望的变体。我们的实验设置为进一步解码HvSTP13响应生物应激。此外，与其他研究一致，我们的实验表明，在宿主病原体相互作用中，糖分配途径的改变是实现植物广泛和持久抗性的有前途的方法。