title: PiHOG1, a stress regulator MAP kinase from the root endophyte fungus Piriformospora indica, confers salinity stress tolerance in rice plants.
abstract: In this study, yeast HOG1 homologue from the root endophyte Piriformospora indica (PiHOG1) was isolated and functionally characterized. Functional expression of PiHOG1 in S. cerevisiae ∆hog1 mutant restored osmotolerance under high osmotic stress. Knockdown (KD) transformants of PiHOG1 generated by RNA interference in P. indica showed that genes for the HOG pathway, osmoresponse and salinity tolerance were less stimulated in KD-PiHOG1 compared to the wild-type under salinity stress. Furthermore, KD lines are impaired in the colonization of rice roots under salinity stress of 200 mM NaCl, and the biomass of the host plants, their shoot and root lengths, root number, photosynthetic pigment and proline contents were reduced as compared to rice plants colonized by WT P. indica. Therefore, PiHOG1 is critical for root colonisation, salinity tolerance and the performance of the host plant under salinity stress. Moreover, downregulation of PiHOG1 resulted not only in reduced and delayed phosphorylation of the remaining PiHOG1 protein in colonized salinity-stressed rice roots, but also in the downregulation of the upstream MAP kinase genes PiPBS2 and PiSSK2 involved in salinity tolerance signalling in the fungus. Our data demonstrate that PiHOG1 is not only involved in the salinity response of P. indica, but also helping host plant to overcome salinity stress.
authors.affiliation: School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India.
authors.forename: Abhimanyu
authors.initials: A
authors.lastname: Jogawat
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Jyothilakshmi
authors.initials: J
authors.lastname: Vadassery
authors.affiliation: School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Verma
authors.affiliation: Institute of Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743 Jena, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Oelmüller
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Dua
authors.affiliation: Department of Evolutionary and Environmental Biology, Institute of Evolution, University of Haifa, 199 Aba Khoushy Ave., Mount Carmel, Haifa, 3498838, Israel.
authors.forename: Eviatar
authors.initials: E
authors.lastname: Nevo
authors.affiliation: School of Life Sciences Jawaharlal Nehru University, New Delhi-110067, India.
authors.forename: Atul Kumar
authors.initials: AK
authors.lastname: Johri
mesh_terms: D001487:Basidiomycota / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D018533:Biomass; D060026:Endophytes / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005816:Genetic Complementation Test; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D012275:Oryza / Q000378:metabolism / Q000382:microbiology; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D034622:RNA Interference; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D054712:Salinity; D055049:Salt Tolerance / Q000235:genetics; D013312:Stress, Physiological
chemical_list: D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases