Department of Plant Pathology and Weed Research, Newe Ya'ar Research Center, Agricultural Research Organization (ARO), Ramat Yishay, Israel.
Department of Biochemistry, School of Basic Sciences, Central University of Punjab, VPO-Ghudda, Bathinda, India.
Sci Rep. 2021 Feb 16;11(1):3905. doi: 10.1038/s41598-021-82897-8.
Root parasitic weeds infect numerous economically important crops, affecting total yield quantity and quality. A lack of an efficient control method limits our ability to manage newly developing and more virulent races of root parasitic weeds. To control the parasite induced damage in most host crops, an innovative biotechnological approach is urgently required. Strigolactones (SLs) are plant hormones derived from carotenoids via a pathway involving the Carotenoid Cleavage Dioxygenase (CCD) 7, CCD8 and More Axillary Growth 1 (MAX1) genes. SLs act as branching inhibitory hormones and strictly required for the germination of root parasitic weeds. Here, we demonstrate that CRISPR/Cas9-mediated targted editing of SL biosynthetic gene MAX1, in tomato confers resistance against root parasitic weed Phelipanche aegyptiaca. We designed sgRNA to target the third exon of MAX1 in tomato plants using the CRISPR/Cas9 system. The T plants were edited very efficiently at the MAX1 target site without any non-specific off-target effects. Genotype analysis of T plants revealed that the introduced mutations were stably passed on to the next generation. Notably, MAX1-Cas9 heterozygous and homozygous T plants had similar morphological changes that include excessive growth of axillary bud, reduced plant height and adventitious root formation relative to wild type. Our results demonstrated that, MAX1-Cas9 mutant lines exhibit resistance against root parasitic weed P. aegyptiaca due to reduced SL (orobanchol) level. Moreover, the expression of carotenoid biosynthetic pathway gene PDS1 and total carotenoid level was altered, as compared to wild type plants. Taking into consideration, the impact of root parasitic weeds on the agricultural economy and the obstacle to prevent and eradicate them, the current study provides new aspects into the development of an efficient control method that could be used to avoid germination of root parasitic weeds.
根寄生杂草感染了许多经济上重要的作物，影响了总产量和质量。缺乏有效的控制方法限制了我们管理新出现的和更具毒性的根寄生杂草的能力。为了控制大多数寄主作物中寄生虫引起的损害，迫切需要一种创新的生物技术方法。独脚金内酯（SLs）是一种植物激素，由类胡萝卜素通过涉及类胡萝卜素裂解双加氧酶（CCD）7、CCD8 和更多侧枝生长 1（MAX1）基因的途径衍生而来。SLs 作为分枝抑制激素，严格要求根寄生杂草的萌发。在这里，我们证明了 CRISPR/Cas9 介导的番茄 SL 生物合成基因 MAX1 的靶向编辑赋予了对根寄生杂草 Phelipanche aegyptiaca 的抗性。我们使用 CRISPR/Cas9 系统设计了针对番茄植株 MAX1 第三外显子的 sgRNA。T 植株在 MAX1 靶位被非常有效地编辑，没有任何非特异性脱靶效应。T 植株的基因型分析表明，引入的突变稳定地传递到下一代。值得注意的是，MAX1-Cas9 杂合和纯合 T 植株的形态变化相似，包括侧芽过度生长、株高降低和不定根形成相对于野生型。我们的结果表明，由于 SL（独脚金醇）水平降低，MAX1-Cas9 突变体系表现出对根寄生杂草 P. aegyptiaca 的抗性。此外，与野生型植物相比，类胡萝卜素生物合成途径基因 PDS1 和总类胡萝卜素水平的表达发生了改变。考虑到根寄生杂草对农业经济的影响以及防止和根除它们的障碍，本研究为开发一种有效的控制方法提供了新的方面，可用于避免根寄生杂草的萌发。
