Modification of starch composition, structure and properties through editing of TaSBEIIa in both winter and spring wheat varieties by CRISPR/Cas9.
Modification of starch composition, structure and properties through editing of TaSBEIIa in both winter and spring wheat varieties by CRISPR/Cas9.
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DOI：
10.1111/pbi.13519
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发表时间：
2021-05
影响因子：
13.8
通讯作者：
Xia L
中科院分区：
文献类型：
--
作者：
Li J;Jiao G;Sun Y;Chen J;Zhong Y;Yan L;Jiang D;Ma Y;Xia L
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.）是全球主要的粮食作物。而现代小麦品种籽粒中RS含量较低。在这里，我们报告了通过CRISPR/Cas9分别在现代冬小麦品种郑麦7698（ZM）和春小麦品种Bobwhite中通过TaSBEIIa的靶向诱变产生高直链淀粉小麦。我们分别在ZM和Bobwhite中产生了一系列具有部分或三重无效TasbeIIa等位基因的无转基因突变株系。对淀粉组成、结构和特性的分析表明，部分或三重无效等位基因的影响具有剂量依赖性，三重无效系对淀粉组成、支链淀粉的精细结构以及理化和营养特性的影响更深远。三无效系面粉中直链淀粉、RS、蛋白质和可溶性戊聚糖含量显著增加，对人体健康有益。烘焙品质分析表明，高直链淀粉面粉可用作添加剂或用于制作饼干。总的来说，我们通过CRISPR/Cas9在冬小麦和春小麦品种中对TaSBEIIa进行靶向诱变，成功地改变了淀粉组成、结构和性质，并产生了无转基因的高直链淀粉小麦。我们的发现为TaSBEIIa在不同遗传背景下确定淀粉组成，结构，性质和最终使用质量方面的作用提供了深刻的见解，并通过基因组编辑提高了RS含量，并通过多种育种和最终用途应用于谷类作物物种以获得健康益处。
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.