title: Shotgun proteomic analysis of long-distance drought signaling in rice roots.
abstract: Rice (Oryza sativa L. cv. IR64) was grown in split-root systems to analyze long-distance drought signaling within root systems. This in turn underpins how root systems in heterogeneous soils adapt to drought. The approach was to compare four root tissues: (1) fully watered; (2) fully droughted and split-root systems where (3) one-half was watered and (4) the other half was droughted. This was specifically aimed at identifying how droughted root tissues altered the proteome of adjacent wet roots by hormone signals and how wet roots reciprocally affected dry roots hydraulically. Quantitative label-free shotgun proteomic analysis of four different root tissues resulted in identification of 1487 nonredundant proteins, with nearly 900 proteins present in triplicate in each treatment. Drought caused surprising changes in expression, most notably in partially droughted roots where 38% of proteins were altered in level compared to adjacent watered roots. Specific functional groups changed consistently in drought. Pathogenesis-related proteins were generally up-regulated in response to drought and heat-shock proteins were totally absent in roots of fully watered plants. Proteins involved in transport and oxidation-reduction reactions were also highly dependent upon drought signals, with the former largely absent in roots receiving a drought signal while oxidation-reduction proteins were strongly present during drought. Finally, two functionally contrasting protein families were compared to validate our approach, showing that nine tubulins were strongly reduced in droughted roots while six chitinases were up-regulated, even when the signal arrived remotely from adjacent droughted roots.
authors: Department of Chemistry and Biomolecular Sciences, Macquarie University, North Ryde, NSW, Australia.
authors: Mehdi
authors: M
authors: Mirzaei
authors: Neda
authors: N
authors: Soltani
authors: Elham
authors: E
authors: Sarhadi
authors: Dana
authors: D
authors: Pascovici
authors: Tim
authors: T
authors: Keighley
authors: Ghasem Hosseini
authors: GH
authors: Salekdeh
authors: Paul A
authors: PA
authors: Haynes
authors: Brian J
authors: BJ
authors: Atwell
mesh_terms: D002450:Cell Communication; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D053858:Metabolic Networks and Pathways / Q000235:genetics; D058977:Molecular Sequence Annotation; D012275:Oryza / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D013312:Stress, Physiological
chemical_list: D010940:Plant Proteins; D020543:Proteome