Foods high in amylose content and resistant starch (RS) offer great potential to improve human health and lower the risk of serious noninfectious diseases. Common wheat (Triticum aestivum L.) is a major staple food crop globally. However, the RS contents in the grains of modern wheat varieties are low. Here, we report the generation of high-amylose wheat through targeted mutagenesis of TaSBEIIa in a modern winter wheat cv Zhengmai 7698 (ZM) and a spring wheat cv Bobwhite by CRISPR/Cas9, respectively. We generated a series of transgene-free mutant lines either with partial or triple-null TasbeIIa alleles in ZM and Bobwhite, respectively. Analyses of starch composition, structure and properties revealed that the effects of partial or triple-null alleles were dosage dependent with triple-null lines demonstrated more profound impacts on starch composition, fine structures of amylopectin and physiochemical and nutritional properties. The flours of triple-null lines possessed significantly increased amylose, RS, protein and soluble pentosan contents which benefit human health. Baking quality analyses indicated that the high-amylose flours may be used as additives or for making cookies. Collectively, we successfully modified the starch composition, structure and properties through targeted mutagenesis of TaSBEIIa by CRISPR/Cas9 in both winter and spring wheat varieties and generated transgene-free high-amylose wheat. Our finding provides deep insights on the role of TaSBEIIa in determining starch composition, structure, properties and end-use quality in different genetic backgrounds and improving RS content with multiple breeding and end-use applications in cereal crop species through genome editing for health benefits.

中文翻译：

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通过编辑CRISPR / Cas9对冬小麦和春小麦品种中TaSBEIIa的淀粉组成，结构和性质的修饰

高直链淀粉含量和抗性淀粉（RS）的食品具有改善人类健康和降低严重非传染性疾病风险的巨大潜力。普通小麦（Triticum aestivum L.）是全球主要的主食作物。但是，现代小麦品种籽粒中的RS含量较低。在这里，我们通过定向诱变的报告高直链淀粉小麦的产生TaSBEIIa在现代小麦品种郑麦7698（ZM）和春小麦品种分别种Bobwhite由CRISPR / Cas9。我们生成了部分或三无效TasbeIIa的一系列无转基因突变株ZM和Bobwhite中的等位基因。对淀粉组成，结构和性质的分析表明，部分或三无效等位基因的影响与剂量有关，而三无效系显示出对淀粉组成，支链淀粉的细微结构以及理化和营养性质的影响更深远。三无效品系的面粉具有明显增加的直链淀粉，RS，蛋白质和可溶性戊聚糖含量，对人体健康有益。烘焙质量分析表明，高直链淀粉面粉可用作添加剂或用于制作饼干。总体而言，我们通过定向诱变TaSBEIIa成功地改变了淀粉的组成，结构和性能。由CRISPR / Cas9开发，用于冬小麦和春小麦品种，并生成了无转基因的高直链淀粉小麦。我们的发现提供了关于TaSBEIIa在确定不同遗传背景下的淀粉组成，结构，特性和最终用途质量以及通过基因组编辑的多种育种和最终用途应用以改善健康的目的提高RS含量方面的作用的深刻见解。