Molecular Basis and Genetics of Stem Rust Resistance in Wheat

Wheat is the staple food for many countries, therefore, it needs more attention as compared to other cultivated crops. Stem rust is one of the major wheat diseases. Fungus spores fall on the plant surface and starts to grow inside the plant tissues. Two groups of resistant genes(R & Avr) have been identified conferring host-specific and non-host specific resistance respectively. Resistance is either achieved through thickening of the cell wall or through the programmed cell death (hypersensitivity) type of response. Every pathogen has specific pathogen-associated molecular patterns PAMPs which are recognized by the receptor protein. i.e. pattern recognition receptors PRRs. Plants can activate separate defence pathways depending on the type of the pathogen encountered. Jasmonic acid (JA) and ethylene-dependent responses seem to be initiated by necrotrophs, whereas salicylic acid (SA) dependent response activated by biotrophic pathogens.