The SlASR gene cloned from the extreme halophyte Suaeda liaotungensis K. enhances abiotic stress tolerance in transgenic Arabidopsis thaliana

Abstract Halophytes have a distinct signaling pathway and regulatory network to impart salt stress tolerance. Environmental signals are first perceived by specific receptors, which modulate expression and activation of different genes leading to stress tolerance. SlASR, an abscisic acid-, stress-, and ripening-induced protein, was previously isolated and characterized from high-throughput Solexa sequencing of extreme halophyte Suaeda liaotungensis K.. SlASR, localized in the nucleus, contained 237 amino acids with a 24.94-kDa molecular mass and an ABA/WDS domain. SlASR had a large number of disorder-promoting amino acids, making it an intrinsically disordered protein. It was not a transcriptional activator in yeast cells. The expression of SlASR was induced by abscisic acid (ABA), NaCl, dehydration, or low temperature treatment. To investigate the biological role of SlASR proteins in abiotic stress responses, we used an overexpression approach in Arabidopsis thaliana . Constitutive overexpression of SlASR under the Cauliflower Mosaic Virus (CaMV) 35S promoter conferred reduced sensitivity to NaCl, drought, and low temperature.