Wheat hybrid necrosis, a long-standing mystery in plant science, has been known to be regulated by two complementary genes, Ne1 and Ne2. In 2021, Ne2 has been characterized as a leaf rust resistance NLR-type resistance protein (Lr13) by three independent research teams. Until recently, Chinese scientists have made a significant progress in isolating Ne1 and understanding hybrid necrosis in wheat, a phenomenon that severely hinders the aggregation of desirable traits and restricts the breeding of new varieties.
On March 18, a research team led by Prof. LIU Zhiyong from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences published a groundbreaking study in
Nature Communications detailing their significant progress in isolating the
Ne1 gene and understanding its role in hybrid necrosis.
The researchers found that Ne1 encodes an α/β hydrolase (ABH) enzyme, which is generated through genomic structural variation. The genetic interaction between Ne1 (ABH) and Ne2 (NLR) activates innate immunity response to induce hybrid necrosis.
Further genomic and genetic analyses confirmed that allelic variation and copy number variation of Ne1 are key factors contributing to the phenotypic diversity of hybrid necrosis in wheat.
Phylogenetic analysis suggested that Ne1 likely originated from wild emmer wheat through gene duplication and ectopic recombination events. Unlike Lr13/Ne2, which is widely used in leaf rust resistance breeding, Ne1 is less frequent in modern wheat varieties due to its negative impact on hybrid necrosis.
The research elucidates the co-evolutionary mechanism of the ABH/NLR gene pair in plant development and innate immunity with significance scientific contribution and application value for improving wheat hybrid breeding efficiency and developing disease-resistant new varieties.
This research was supported by the STI 2030-Major Projects, the Strategic Priority Research Program of CAS, and the National Natural Science Foundation of China, etc.
