title: Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling.
abstract: To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na(+)/K(+) ratios in shoots, and Na(+) translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na(+) in its roots and increasing K(+) in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation-reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177.
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Wen-Sheng
authors.initials: WS
authors.lastname: Wang
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Xiu-Qin
authors.initials: XQ
authors.lastname: Zhao
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China School of Science, Anhui Agricultural University, Hefei 230036, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Li-Yu
authors.initials: LY
authors.lastname: Huang
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China.
authors.forename: Jian-Long
authors.initials: JL
authors.lastname: Xu
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Yan-Ru
authors.initials: YR
authors.lastname: Cui
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China lizhikang@caas.cn fubinying@caas.cn.
authors.forename: Bin-Ying
authors.initials: BY
authors.lastname: Fu
authors.affiliation: Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China lizhikang@caas.cn fubinying@caas.cn.
authors.forename: Zhi-Kang
authors.initials: ZK
authors.lastname: Li
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D005838:Genotype; D055442:Metabolome; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D018520:Plant Shoots / Q000187:drug effects / Q000502:physiology; D055049:Salt Tolerance; D012965:Sodium Chloride / Q000494:pharmacology*; D059467:Transcriptome
chemical_list: D012965:Sodium Chloride; D000040:Abscisic Acid
keywords: ABA; Oryza sativa L; metabolomics; molecular mechanisms; salt tolerance; transcriptome.