Overexpression of Arabidopsis thaliana Na+/H+ antiporter gene enhanced salt resistance in transgenic poplar (Populus × euramericana ‘Neva’)

Abstract

Salinity is a major abiotic stress factor limiting plant growth and productivity. One possible method to enhance plant salt-resistance is to compartmentalize sodium ions away from the cytosol. In the present work, a vacuolar Na ? /H ? antiporter gene AtNHX1 from Arabidopsis thaliana, was transferred into Populus 9 euramericana 'Neva' by Agrobacterium tumefaciens in order to enhance poplar salt-resistance. The results showed that the transgenic poplar were more resistant to NaCl than the wild-type (WT) in greenhouse condition. Compared with the WT, plant growth and photosynthetic capacity of the transgenic plants were enhanced, and the transgenic plants accumulated more Na ? and K ? in roots and leaves under the same NaCl condition, whereas malondialdehyde and relative electrical conductivity were lower. All of these properties of the transgenic poplar were likely to be a consequence of the overexpression of AtNHX1 caused Na ? sequestration in the vacuoles and improved K ? absorption, thus reducing their toxic effects. These results indicated overexpression of the AtNHX1 enhanced salt-resistance of poplar, and AtNHX1 played an important role in the compartmentation of Na ? into the vacuoles. Therefore, this study provides an effective way for improving salt resistance in trees.

Functional analysis of the 1-aminocyclopropane-1-carboxylate deaminase gene of the biocontrol fungus Trichoderma asperellum ACCC30536

“…The possible cause of the result is that downstream genes preventing chlorophyll decomposition are activated by the ACCD gene product, enabling the maintenance of a much higher chlorophyll concentration (Gao et al 2009). In addition, the following conclusions of Nicotiana tabaccum osmotin gene expression in transgenic chilli pepper (Subramanyam et al 2011), SBgLR gene and TSRF1 gene in maize (Wang et al 2013), P5CS gene in tobacco (Mahboobeh and Akba 2013), AtNHX1 gene in poplar ATHK1 (Jiang et al 2012), are also consistent with our findings that transgenic plants had a lower chlorophyll loss and then a higher salt tolerance compared to non-transformed plants under salt stress.…”

Effects of selenium on the growth and photosynthetic characteristics of flue-cured tobacco (Nicotiana tabacum L.)

“…At 40 d after the treatments, the MDA contents in the newly expanded leaves of the labeled leaf segments were measured as previously described [18]. The absorbance at 450, 532, and 600 nm was obtained with an ultraviolet spectrophotometer (UV-755B, Shanghai Precision and Scientific Instrument Co., Ltd., China).…”

Salicornia europaea L. Na+/H+ antiporter gene improves salt tolerance in transgenic alfalfa (Medicago sativa L.)

“…For example, transgenic A. thaliana, groundnut (Arachis hypogaea), kiwifruit (Actinidia deliciosa), and poplar plants with AtNHX1 grew normally in 200 mM NaCl (Apse et al, 1999;Asif et al, 2011;Tian et al, 2011;Jiang et al, 2012). Alfalfa and tomato that overexpressed TaNHX2 showed improved tolerance to salt (Zhang et al, 2012;Yarra et al, 2012).…”

“…Recently, many Na + /H + antiporter genes have been identified and characterized in various plant species, including Arbidopsis thaliana (Apse et al, 1999), Oryza sativa (Fukuda et al, 1999), alfalfa (An et al, 2008), Salsola soda , Chrysanthemum crassum (Song et al, 2012), Cucumis sativus (Wang et al, 2013), and Zea mays (Pitann et al, 2013). The primary function conferring salt tolerance of these genes had been manifested by transgenic events in many plants (Asif et al, 2011;Tian et al, 2011;Uliaie et al, 2012;Jiang et al, 2012;Yarra et al, 2012). These transgenic events have clearly shown the feasibility of breeding salt-tolerant crops by using the Na + /H + antiporter genes.…”