Improved salt tolerance in tobacco plants by co-transformation of a betaine synthesis gene BADH and a vacuolar Na+/H+ antiporter gene SeNHX1

Abstract

Three types of transgenic tobacco plants were acquired by separate transformation or co-transformation of a vacuolar Na(+)/H(+) antiporter gene, SeNHX1, and a betaine synthesis gene, BADH. When exposed to 200 mM NaCl, the dual gene-transformed plants displayed greater accumulation of betaine and Na(+) than their wild-type counterparts. Photosynthetic rate and photosystem II activity in the transgenic plants were less affected by salt stress than wild-type plants. Transgenic plants exhibited a greater increase in osmotic pressure than wild-type plants when exposed to NaCl. More importantly, the dual gene transformed plants accumulated higher biomass than either of the single transgenic plants under salt stress. Taken together, these findings indicate that simultaneous transformation of BADH and SeNHX1 genes into tobacco plants can enable plants to accumulate betaine and Na(+), thus conferring them more tolerance to salinity than either of the single gene transformed plants or wild-type tobacco plants.

Cloning and characterization of a novel betaine aldehyde dehydrogenase gene from Suaeda corniculata

“…Our data also revealed that glycine betaine accumulation is induced by salt treatment. The protective role of betaine may lie in its strong stabilizing effects on the structure and function of the oxygenevolving PSII complex (Ohnishi and Murata, 2006;Zhou et al, 2008). This is consistent with transgenic plants containing high betaine levels having enhanced tolerance to abiotic stress.…”

“…Glycine betaine protects the plant from salt stress by maintaining the osmotic balance under various abiotic stresses (Wani et al, 2013) and by stabilizing the quaternary structure of complex proteins (Bernard et al, 1988). In photosynthetic systems, glycine betaine stabilizes the oxygen-evolving photosystem II complex and Rubisco at elevated salt concentrations (Zhou et al, 2008;Fan et al, 2012).…”

Genetic engineering of glycine betaine biosynthesis to enhance abiotic stress tolerance in plants

“…The coexpression of Na ϩ /H ϩ antiporters with genes of the GB biosynthetic pathway has the potential to increase salt tolerance by many times. Recently, co-transformation of the Na ϩ /H ϩ antiporter gene (SeNHX1) and BADH was reported in tobacco (Zhou et al 2008). The resulting transgenic plants accumulated more GB and showed higher biomass than either the single-gene transgenic plants or untransformed controls.…”

Overexpression ofSeNHX1improves both salt tolerance and disease resistance in tobacco

“…1 Evidences in the NHX1 transgenic plants and yeasts support the enhanced tolerance to salt stress by overexpressing Na C /H C exchangers. [2][3][4] Recent studies suggest NHX1 affect the lumen pH 5 by regulating H C transportation, which is associated with cellular ROS metabolism. [6][7][8] In our previous study, we found NHX1 could regulate cellular ROS level, and participate in plant disease defense.…”

“…9 However, no evidence demonstrates that transformation of NHX1 could improve both salt tolerance and disease defense in plant. In this study, the T1 progenies of Nicotiana tabacum L. (Wisconsin 38) lines expressing SeNHX1 (from Salicornia europaea) were generated, 4 which were used to investigate the resistance to Phytophthora parasitica var nicotianae (Ppn) and the salt tolerance.…”