title: Elucidation of defense-related signaling responses to spot blotch infection in bread wheat (Triticum aestivum L.).
abstract: Spot blotch disease, caused by Bipolaris sorokiniana, is an important threat to wheat, causing an annual loss of ~17%. Under epidemic conditions, these losses may be 100%, yet the molecular responses of wheat to spot blotch remain almost uncharacterized. Moreover, defense-related phytohormone signaling genes have been poorly characterized in wheat. Here, we have identified 18 central components of salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and enhanced disease susceptibility 1 (EDS1) signaling pathways as well as the genes of the phenylpropanoid pathway in wheat. In time-course experiments, we characterized the reprogramming of expression of these pathways in two contrasting genotypes: Yangmai #6 (resistant to spot blotch) and Sonalika (susceptible to spot blotch). We further evaluated the performance of a population of recombinant inbred lines (RILs) by crossing Yangmai#6 and Sonalika (parents) and subsequent selfing to F10 under field conditions in trials at multiple locations. We characterized the reprogramming of defense-related signaling in these RILs as a consequence of spot blotch attack. During resistance to spot blotch attack, wheat strongly elicits SA signaling (SA biogenesis as well as the NPR1-dependent signaling pathway), along with WRKY33 transcription factor, followed by an enhanced expression of phenylpropanoid pathway genes. These may lead to accumulation of phenolics-based defense metabolites that may render resistance against spot blotch. JA signaling may synergistically contribute to the resistance. Failure to elicit SA (and possibly JA) signaling may lead to susceptibility against spot blotch infection in wheat.
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Ranabir
authors.initials: R
authors.lastname: Sahu
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Murali
authors.initials: M
authors.lastname: Sharaff
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Maitree
authors.initials: M
authors.lastname: Pradhan
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Avinash
authors.initials: A
authors.lastname: Sethi
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Tirthankar
authors.initials: T
authors.lastname: Bandyopadhyay
authors.affiliation: Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 22105, India.
authors.forename: Vinod K
authors.initials: VK
authors.lastname: Mishra
authors.affiliation: Department of Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 22105, India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Chand
authors.affiliation: Uttar Banga Krishi Viswavidyalaya, Cooch Behar, Varanasi, 736165, West Bengal, India.
authors.forename: Apurba K
authors.initials: AK
authors.lastname: Chowdhury
authors.affiliation: Department of Genetics and Plant Breeding, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 22105, India.|The International Maize and Wheat Improvement Center (CIMMYT) South Asia Office, Singh Durbar Plaza Marg, Kathmandu, Nepal.
authors.forename: Arun K
authors.initials: AK
authors.lastname: Joshi
authors.affiliation: Department of Biological Sciences, Indian Institute of Science Education and Research - Kolkata, Mohanpur Campus, Mohanpur, 741246, West Bengal, India.
authors.forename: Shree P
authors.initials: SP
authors.lastname: Pandey
mesh_terms: D001203:Ascomycota / Q000166:cytology / Q000502:physiology*; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007178:Inbreeding; D058977:Molecular Sequence Annotation; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology*; D010937:Plant Growth Regulators / Q000378:metabolism*; D057865:Plant Immunity; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000502:physiology; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction; D014908:Triticum / Q000235:genetics / Q000276:immunology / Q000502:physiology*
chemical_list: D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; C036216:ethylene; D020156:Salicylic Acid
keywords: Bipolaris sorokiniana; Triticum aestivum; gene annotation; phenolic acids; phytohormone signaling; plant defense; recombinant inbred line; salicylic acid; spot blotch; wheat