Broad-spectrum resistance to bacterial blight in rice using genome editing

First author: Ricardo Oliva; Affiliations: International Rice Research Institute (国际水稻研究所): Metro Manila, Philippines

Corresponding author: Ricardo Oliva

Bacterial blight of rice is an important disease in Asia and Africa. The pathogen, Xanthomonas oryzae pv. oryzae (Xoo), secretes one or more of six known transcription-activator-like effectors (TALes) that bind specific promoter sequences and induce, at minimum, one of the three host sucrose transporter genes SWEET11, SWEET13 and SWEET14, the expression of which is required for disease susceptibility. We used CRISPR–Cas9-mediated genome editing to introduce mutations in all three SWEET gene promoters. Editing was further informed by sequence analyses of TALe genes in 63 Xoo strains, which revealed multiple TALe variants for SWEET13 alleles. Mutations were also created in SWEET14, which is also targeted by two TALes from an African Xoo lineage. A total of five promoter mutations were simultaneously introduced into the rice line Kitaake and the elite mega varieties IR64 and Ciherang-Sub1. Paddy trials showed that genome-edited SWEET promoters endow rice lines with robust, broad-spectrum resistance.

水稻白叶枯病在亚洲和非洲是非常严重的作物病害。该病害的病原体为水稻黄单胞菌水稻致病变种Xoo，已知能够分泌六种类转录激活效应物TALes中的一种或多种，这些效应物能够结合特定的启动子序列并诱导至少三种宿主蔗糖转运蛋白基因SWEET11/13/14中的一个，而这些基因的表达对于作物的病害易感性是必需的。本文作者通过CRISPR–Cas9介导的基因组编辑在这三个SWEET基因的启动子区引入突变。通过对63个Xoo菌株中TALe基因的序列分析进一步了解了编辑过程，揭示了SWEET13等位基因的多个TALe变体。作者在SWEET14中也制造了突变，该基因能够被两个来自非洲Xoo支系的TALes所靶向。作者将五个启动子突变同时引入到水稻系Kitaake和优良水稻品种IR64和Ciherang-Sub1中。 水田种植试验显示，SWEET启动子经过基因编辑的株系赋予了水稻更加强大的、广谱抗性。

通讯：Ricardo Oliva (https://www.irri.org/about-us/our-people/ricardo-oliva)

研究方向：作物育种改良。

doi: https://doi.org/10.1038/s41587-019-0267-z

Journal: Nature Biotechnology

Published date: October 28, 2019