Zhang Hengyou, Yan Liuling, Huang Yinghua
Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
USDA-ARS Plant Science Research Laboratory, 1301N, Western Rd, Stillwater, OK 74075, USA.
Int J Mol Sci. 2024 Dec 24;26(1):19. doi: 10.3390/ijms26010019.
Greenbug, , is one of the important cereal aphid pests of sorghum in the United States and other parts of the world. variety PI 607900 carries the resistance () gene that underlies plant resistance to greenbug biotype I (GBI). Now, the has been determined as the major gene conferring greenbug resistance based on the strong association of its presence with the resistance phenotype in sorghum. In this study, we have successfully isolated the gene using a map-based cloning approach, and subsequent molecular characterization revealed it encodes a leucine-rich repeat containing receptor-like protein (LRR-RLP). According to DNA sequence analysis, the gene are conserved among GBI-resistance sorghum accessions but are variable within susceptible lines. Furthermore, an InDel (-965 nt) at its promoter region and a single-nucleotide polymorphism (SNP, 592 nt) in the CDS of the were detected and they are well conserved within resistant genotypes. When the gene was cloned and transferred into plants, the was activated in the transgenic plants in response to attack by green peach aphids according to the results of the histochemical assay, and GUS activity was detected in situ in spots around the vasculature of the leaf where the phloem is located, suggesting its biological function in those transgenic plants. Overall, this study confirms that the gene coding for an LRR-RLP is the major resistance gene to greenbug, a destructive pest in sorghum and wheat. This represents the first greenbug resistance gene cloned so far and indicates that the simple-inherited GBI resistance gene can be used for sorghum improvement with genetic resistance to GBI via molecular breeding or cross-based conventional breeding technologies.
麦二叉蚜是美国和世界其他地区高粱的重要谷类蚜虫害虫之一。品种PI 607900携带对麦二叉蚜生物型I（GBI）具有植物抗性的抗性（）基因。现在，基于其存在与高粱抗性表型的强关联，已确定该基因是赋予麦二叉蚜抗性的主要基因。在本研究中，我们使用基于图谱的克隆方法成功分离了该基因，随后的分子表征表明它编码一种富含亮氨酸重复序列的受体样蛋白（LRR - RLP）。根据DNA序列分析，该基因在GBI抗性高粱种质中是保守的，但在感病品系中是可变的。此外，在其启动子区域检测到一个InDel（-965 nt），在该基因的编码区检测到一个单核苷酸多态性（SNP，592 nt），它们在抗性基因型中高度保守。当该基因被克隆并转入植物中时，根据组织化学分析结果，在转基因植物中，该基因在受到桃蚜攻击时被激活，并且在韧皮部所在的叶脉周围的斑点中检测到GUS活性，表明其在这些转基因植物中的生物学功能。总体而言，本研究证实编码LRR - RLP的该基因是对高粱和小麦中的毁灭性害虫麦二叉蚜的主要抗性基因。这代表了迄今为止克隆的第一个麦二叉蚜抗性基因，并表明简单遗传的GBI抗性基因可通过分子育种或基于杂交的传统育种技术用于高粱对GBI的遗传抗性改良。
