Genome-edited powdery mildew resistance in wheat without growth penalties
Genome-edited powdery mildew resistance in wheat without growth penalties
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DOI：
10.1038/s41586-022-04395-9
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发表时间：
2022-02-09
期刊：
影响因子：
64.8
通讯作者：
Gao, Caixia
中科院分区：
文献类型：
--
作者：
Li, Shengnan;Lin, Dexing;Gao, Caixia
破坏农作物的易感性 (S) 基因是一种具有吸引力的赋予抗病性的育种策略 (1,2)。然而，S 基因涉及许多重要的生物学功能，删除这些基因通常会导致不良的多效性效应 (1)。此类 S 基因（抗霉基因座 O (MLO)）的功能丧失突变可赋予多种植物物种持久且广谱的白粉病抗性(2)(,3)。然而，与mio相关的抗性也伴随着生长惩罚和产量损失，从而限制了其在农业中的广泛使用。在这里，我们描述了 Tamlo-R32，这是一种在小麦 MLO-B1 基因座中具有 304 KB 对靶向缺失的突变体，可保留作物生长和产量，同时赋予强大的白粉病抗性。我们发现这种缺失会导致局部染色质景观的改变，从而导致液泡膜单糖转运蛋白 3 (TaTMT3B) 的异位激活，并且这种激活减轻了与 MLO 破坏相关的生长和产量损失。值得注意的是，TMT3 的功能在其他植物物种（例如拟南芥）中是保守的。此外，精确的基因组编辑有助于将这种 mlo 抗性等位基因 (Tamlo-R32) 快速引入优良小麦品种中。这项工作证明了通过叠加遗传变化来挽救隐性等位基因引起的生长缺陷的能力，这对于开发具有强大而持久的抗病性的高产作物品种至关重要。
Disruption of susceptibility (S) genes in crops is an attractive breeding strategy for conferring disease resistance(1,2). However, S genes are implicated in many essential biological functions and deletion of these genes typically results in undesired pleiotropic effects(1). Loss-of-function mutations in one such S gene, Mildew resistance locus O (MLO), confers durable and broad-spectrum resistance to powdery mildew in various plant species(2)(,3). However, mio-associated resistance is also accompanied by growth penalties and yield losses', thereby limiting its widespread use in agriculture. Here we describe Tamlo-R32, a mutant with a 304-kilobase pair targeted deletion in the MLO-B1 locus of wheat that retains crop growth and yields while conferring robust powdery mildew resistance. We show that this deletion results in an altered local chromatin landscape, leading to the ectopic activation of Tonoplast monosaccharide transporter 3 (TaTMT3B), and that this activation alleviates growth and yield penalties associated with MLO disruption. Notably, the function of TMT3 is conserved in other plant species such as Arabidopsis thaliana. Moreover, precision genome editing facilitates the rapid introduction of this mlo resistance allele (Tamlo-R32) into elite wheat varieties. This work demonstrates the ability to stack genetic changes to rescue growth defects caused by recessive alleles, which is critical for developing high-yielding crop varieties with robust and durable disease resistance.