title: Overexpression of AtLEA3-3 confers resistance to cold stress in Escherichia coli and provides enhanced osmotic stress tolerance and ABA sensitivity in Arabidopsis thaliana.
abstract: Previous studies have shown that the late embryogenesis abundant (LEA) group 3 proteins significantly respond to changes in environmental conditions. However, reports that demonstrate their biological role, especially in Arabidopsis, are notably limited. This study examines the functional roles of the Arabidopsis LEA group 3 proteins AtLEA3-3 and AtLEA3-4 in abiotic stress and ABA treatments. Expression of AtLEA3-3 and AtLEA3-4 is upregulated by ABA, high salinity, and osmotic stress. Results on the ectopic expression of AtLEA3-3 and AtLEA3-4 in E. coli suggest that both proteins play important roles in resistance to cold stress. Overexpression of AtLEA3-3 in Arabidopsis (AtLEA3-3-OE) confers salt and osmotic stress tolerance that is characterized during germination and early seedling establishment. However, AtLEA3-3-OE lines show sensitivity to ABA treatment during early seedling development. These results suggest that accumulation of AtLEA3-3 mRNA and/or proteins may help heterologous ABA re-initiate second dormancy during seedling establishment. Analysis of yellow fluorescent fusion proteins localization shows that AtLEA3-3 and AtLEA3-4 are mainly distributed in the ER and that AtLEA3-3 also localizes in the nucleus, and in response to salt, mannitol, cold, or BFA treatments, the localization of AtLEA3-3 and AtLEA3-4 is altered and becomes more condensed. Protein translocalization may be a positive and effective strategy for responding to abiotic stresses. Taken together, these results suggest that AtLEA3-3 has an important function during seed germination and seedling development of Arabidopsis under abiotic stress conditions.
authors.affiliation: Laboratory of Plant Stress Ecophysiology and Biotechnology, Shapotou Desert Research and Experiment Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Donggang West Road 320, Lanzhou City, Gansu Province 730000, PR China.
authors.forename: Pengshan
authors.initials: P
authors.lastname: Zhao
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Miao
authors.initials: M
authors.lastname: Ma
authors.forename: Jiao
authors.initials: J
authors.lastname: Gong
authors.forename: Qiujun
authors.initials: Q
authors.lastname: Wang
authors.forename: Pengfei
authors.initials: P
authors.lastname: Jia
authors.forename: Guochang
authors.initials: G
authors.lastname: Zheng
authors.forename: Heng
authors.initials: H
authors.lastname: Liu
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D060054:Agrobacterium / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000235:genetics; D009994:Osmolar Concentration; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010957:Plasmids; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D054712:Salinity; D012492:Salts / Q000494:pharmacology; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013312:Stress, Physiological / Q000187:drug effects; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D020033:Protein Isoforms; D012492:Salts; C066246:late embryogenesis abundant protein, plant; D000040:Abscisic Acid