Wheat mutant MNR220 delays haustoria formation during leaf rust pathogenesis at the seedling stage
- Talajoor, Mina [ Montana State University: Plant Sciences & Plant Pathology ]
- Wang, Xiaojing [ Montana State University: Plant Sciences & Plant Pathology ] [ Northwest A&F Univ, Coll Life Sci, State Key Lab Crop Stress Biol Arid Areas, Yangling 712100, Shaanxi, Peoples R China ]
- Zhang, Hongtao [ Montana State University: Plant Sciences & Plant Pathology ]
- Zhang, Peng [ Univ Sydney, Plant Breeding Inst, Cobbitty, NSW 2570, Australia ]
- Bhavani, Sridhar [ Int Maize & Wheat Improvement Ctr CIMMYT, ICRAF House,United Nations Ave,POB 1041, Nairobi 00621, Kenya ]
- Tabe, Linda [ CSIRO Plant Ind, GPO Box 1600, Canberra, ACT 2601, Australia ]
- Lagudah, Evans [ CSIRO Plant Ind, GPO Box 1600, Canberra, ACT 2601, Australia ]
- Huang, Li [ Montana State University: Plant Sciences & Plant Pathology ]
This study reports further characterization of the defence mechanism of an EMS-induced mutant (MNR220) that displays enhanced resistance to leaf rust, stem rust, stripe rust and powdery mildew diseases. The broad-spectrum resistance of the mutant was characterized by a microscopy study and additional race screenings of two rust pathogens. The mutant displayed less disease severity in response to all the races tested, when compared with the wild-type. The microscopy study of the pathogenesis of a leaf rust race PBJJG on the mutant revealed that the resistance was first evident at the pre-haustorial stage; formation of haustoria was significantly delayed or inhibited in the mutant compared with the wild-type. The mutant displayed microscopic level of cell death even in the absence of any pathogens. These findings suggest that MNR220 mediates a spontaneous cell death that delays the infection process by delaying haustoria formation of the pathogen.