Over-expression of the Peroxisomal Ascorbate Peroxidase (SbpAPX) Gene Cloned from Halophyte Salicornia brachiata Confers Salt and Drought Stress Tolerance in Transgenic Tobacco

Abstract

Salicornia brachiata Roxb., an extreme halophyte, is a naturally adapted higher plant model for additional gene resources to engineer salt tolerance in plants. Ascorbate peroxidase (APX) plays a key role in protecting plants against oxidative stress and thus confers abiotic stress tolerance. A full-length SbpAPX cDNA, encoding peroxisomal ascorbate peroxidase, was cloned from S. brachiata. The open reading frame encodes for a polypeptide of 287 amino acid residues (31.3-kDa protein). The deduced amino acid sequence of the SbpAPX gene showed characteristic peroxisomal targeting sequences (RKRAI) and a C-terminal hydrophobic region of 39 amino acid residues containing a transmembrane domain (TMD) of 23 amino acid residues. Northern blot analysis showed elevated SbpAPX transcript in response to salt, cold, abscisic acid and salicylic acid stress treatments. The SbpAPX gene was transformed to tobacco for their functional validation under stresses. Transgenic plants over-expressing SbpAPX gene showed enhanced salt and drought stress tolerance compared to wild-type plants. Transgenic plants showed enhanced vegetative growth and germination rate both under normal and stressed conditions. Present study revealed that the SbpAPX gene is a potential candidate, which not only confers abiotic stress tolerance to plants but also seems to be involved in plant growth.

Non-targeted metabolomics and scavenging activity of reactive oxygen species reveal the potential of Salicornia brachiata as a functional food

“…Some species of Salicornia have shown important biological properties, such as antioxidant, anti-inflammatory, hypoglycemic and cytotoxic activities (Isca, Seca, Pinto, & Silva, 2014). Furthermore, Salicornia is being widely explored for abiotic stress-responsive genes and promoters to develop transgenic plants that can withstand adverse environmental conditions (Chaturvedi, Mishra, Tiwari, & Jha, 2012;Chaturvedi, Patel, Mishra, Tiwari, & Jha, 2014;Jha, Sharma, & Mishra, 2011;Singh, Mishra, & Jha, 2014a, 2014bUdawat, Mishra, & Jha, 2014). No information is available, so far, on the metabolomics of this important succulent halophytic plant.…”

Effect of MgCl2 and double concentration of Murashige and Skoog medium on in vitro plantlet and root cultures generation in halophytic grasswort Salicornia brachiata

“…It accumulates 30-40 % salt in its tissues and so able to grow luxuriously in salt marshes. Ascorbate peroxidase (APX) in this plant plays important role in protecting plants against oxidative stress and thus confers abiotic stress tolerance (Singh et al 2014). It is considered as a potential alternative crop for seawater agriculture in coastal areas.…”

Ascorbate peroxidase from Jatropha curcas enhances salt tolerance in transgenic Arabidopsis

“…Our present data indicate that JcAPX is gradually and strongly induced by NaCl stress ( Figure 3B). Similarly, the expression of APX genes from other species is upregulated under salt stress (Sun et al, 2010;Liu et al, 2014;Singh et al, 2014).…”