Ipomoea pes-caprae IpASR Improves Salinity and Drought Tolerance in Transgenic Escherichia coli and Arabidopsis

Abstract

Ipomoea pes-caprae L. is an extremophile halophyte with strong adaptability to seawater and drought. It is widely used in the ecological restoration of coastal areas or degraded islands in tropical and subtropical regions. In this study, a new abscisic acid, stress and ripening (ASR) gene, IpASR, was reported, and is mainly associated with biological functions involved in salt and drought tolerance. Sequence analysis of IpASR showed that this protein contains an ABA/WDS (abscisic acid/water deficit stress) domain, which is a common feature of all plant ASR members. Overexpression of IpASR improved Escherichia coli growth performance compared with the control under abiotic stress treatment. The transgenic overexpressing IpASR Arabidopsis showed higher tolerance to salt and drought stress than the wild type and lower accumulation of hydrogen peroxide (H2O2) and superoxide (O2−) accompanied by increased antioxidant enzyme activity in vivo. IpASR exhibits transcription factor’s activity. Therefore, the overexpression of IpASR in Arabidopsis is supposed to influence the expression of some genes involved in anti-oxidative and abiotic stresses. The results indicate that IpASR is involved in the plant response to salt and drought and probably acts as a reactive oxygen species scavenger or transcription factor, and therefore influences physiological processes associated with various abiotic stresses in plants.

Isolation and characterization of an atypical LEA gene (IpLEA) from Ipomoea pes-caprae conferring salt/drought and oxidative stress tolerance

“…The seeds germination, seedling planting and stress or hormone treatment of I . pes-caprae was performed as previously described 27,28 . In brief, the seedlings with 4–6 true leaves were used for stress treatment assays to assess the expression patterns of IpLEA .…”

“…All of Arabidopsis plants, including germinating seeds and seedlings, were put in a controlled environment greenhouse at 22 °C, with a 16-h light/8-h darkness photoperiod, a light intensity of 120 mmol m −2 s −1 , and 60–80% relative humidity. Three T3 homozygous transgenic lines were picked out and confirmed by PCR, and then were accessed for further phenotypic analysis as previously described 27,28 . To identify the expression patterns of the salt/drought stress response genes in Arabidopsis, transgenic lines and WT (3-week-old) seedlings planted in vermiculite were immersed in 200 mM NaCl or 300 mM mannitol solutions for 24 h, following which the leaves were harvested for RNA isolation.…”

ZmASR3 from the Maize ASR Gene Family Positively Regulates Drought Tolerance in Transgenic Arabidopsis

“…ASR genes were first identified in tomatoes, and since then, many ASR genes have been reported in various species, including dicotyledonous, monocotyledonous, xylophyta, and herbaceous plants, whereas no ASR genes have been found in Arabidopsis [11,12,13,14,15,16,17]. ASR proteins have been reported to participate in the processes of plant development, senescence, and fruit ripening [18,19,20]. ASR genes have also been reported to respond to ABA and abiotic stresses.…”

Genome-wide characterization of the abscisic acid-, stress- and ripening-induced (ASR) gene family in wheat (Triticum aestivum L.)

“…The transgenic rice with overexpression of OsASR1 and transgenic maize with overexpression of ZmASR1 increased their cold tolerance [36,43]. Transgenic Arabidopsis plants with overexpression of ipomoea pes-caprae IpASR and oxtail millet SiASR4 both enhanced the tolerance to salt stress [33,44].…”