Home • Puccinia triticina 1-1 BBBD Race 1
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Close-up of wheat leaf rust (''Puccinia triticinia'') on wheat. Photo by James Kolmer.

This genome was sequenced by the Broad Institute.

Description of Puccinia triticina has been quoted from Broad.  

Puccinia triticina, the causative agent of wheat leaf rust (also known as brown rust of wheat), is one of the most serious diseases of wheat in North-America and throughout the world. Severe epidemics caused by leaf rust and stem rust, caused by the related species P. graminis f. sp. tritici, plague North-American wheat production. Wheat resistance to cereal rusts is precarious at all times, as new races evolve regularly and threaten sustainable crop production. Genetic resistance remains the most economical and environmentally sound method of minimizing yield losses due to rust fungi, but development of wheat cultivars with long-lasting leaf rust resistance has been complicated by the highly variable nature of P. triticina.

P. triticina is a basidiomycete and belongs to the subphylum Pucciniomycotina, which contains approximately one-third of all described species of basidiomycetes species. Puccinia is the largest genus of rust fungi and currently contains approximately 4,000 species. P. graminis, P. striiformis, and P. triticina represent distinct lineages within the cereal and grass rusts.

P. triticina has a complex life cycle which includes five different spore types and two hosts, wheat and its alternate host meadow rue (Thalictrum speciosissimum) on which it completes its sexual stage. The asexual uredinial stage on wheat is the economically important part of the life cycle which can progress from initial infection to sporulation within ten days under warm and humid conditions, potentially leading to epidemics. During infection on wheat, the pathogen undergoes a high degree of morphological and physiological differentiation. After landing on a wheat epidermis, the dikaryotic urediniospore germinates within hours when sufficient moisture is available. Germination and formation of infection structures are affected by chemical, temperature and surface contact responses. The emerging germ tube extends until a stomatal pore is encountered. Thigmotropic responses to the topology of the leaf surface and negative phototropism help direct the germ tube to a stoma where an appressorium is produced over the stomatal aperture.

 

Genome Reference(s)

Credit

  • Puccinia Group Sequencing Project, Broad Institute of Harvard and MIT