Ectopic Expression of Aeluropus littoralis Plasma Membrane Protein Gene AlTMP1 Confers Abiotic Stress Tolerance in Transgenic Tobacco by Improving Water Status and Cation Homeostasis.
We report here the isolation and functional analysis of AlTMP1 gene encoding a member of the PMP3 protein family. In Aeluropus littoralis, AlTMP1 is highly induced by abscisic acid (ABA), cold, salt, and osmotic stresses. Transgenic tobacco expressing AlTMP1 exhibited enhanced tolerance to salt, osmotic, H₂O₂, heat and freezing stresses at the seedling stage. Under greenhouse conditions, the transgenic plants showed a higher level of tolerance to drought than to salinity. Noteworthy, AlTMP1 plants yielded two- and five-fold more seeds than non-transgenic plants (NT) under salt and drought stresses, respectively. The leaves of AlTMP1 plants accumulated lower Na⁺ but higher K⁺ and Ca2+ than those of NT plants. Tolerance to osmotic and salt stresses was associated with higher membrane stability, low electrolyte leakage, and improved water status. Finally, accumulation of AlTMP1 in tobacco altered the regulation of some stress-related genes in either a positive (NHX1, CAT1, APX1, and DREB1A) or negative (HKT1 and KT1) manner that could be related to the observed tolerance. These results suggest that AlTMP1 confers stress tolerance in tobacco through maintenance of ion homeostasis, increased membrane integrity, and water status. The observed tolerance may be due to a direct or indirect effect of AlTMP1 on the expression of stress-related genes which could stimulate an adaptive potential not present in NT plants.
['Ben Romdhane|Walid|W|', 'Ben-Saad|Rania|R|', 'Meynard|Donaldo|D|', 'Verdeil|Jean-Luc|JL|', 'Azaza|Jalel|J|', 'Zouari|Nabil|N|', 'Fki|Lotfi|L|', 'Guiderdoni|Emmanuel|E|', 'Al-Doss|Abdullah|A|', 'Hassairi|Afif|A|']
D000040:Abscisic Acid D001483:Base Sequence D002412:Cations D000066630:Ectopic Gene Expression D008353:Mannitol D008565:Membrane Proteins D008969:Molecular Sequence Data D009997:Osmotic Pressure D010802:Phylogeny D018515:Plant Leaves D010940:Plant Proteins D030821:Plants, Genetically Modified D006109:Poaceae D036226:Seedlings D012965:Sodium Chloride D013312:Stress, Physiological D013696:Temperature D014026:Tobacco D014867:Water
Aeluropus littoralis plasma membrane protein AlTMP1 transgenic tobacco drought and salt tolerance