Aldo-keto reductase-1 (AKR1) protect cellular enzymes from salt stress by detoxifying reactive cytotoxic compounds

Cytotoxic compounds like reactive carbonyl compounds such as methylglyoxal (MG), melandialdehyde (MDA), besides the ROS accumulate significantly at higher levels under salinity stress conditions and affect lipids and proteins that inhibit plant growth and productivity. The detoxification of these cytotoxic compounds by overexpression of NADPH-dependent Aldo-ketoreductase (AKR1) enzyme enhances the salinity stress tolerance in tobacco. The PsAKR1 overexpression plants showed higher survival and chlorophyll content and reduced MDA, H2O2, and MG levels under NaCl stress. The transgenic plants showed reduced levels of Na+ levels in both root and shoot due to reduced reactive carbonyl compounds (RCCs) and showed enhanced membrane stability resulted in higher root growth and biomass. The increased levels of antioxidant glutathione and enhanced activity of superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) suggest AKR1 could protect these enzymes from the RCC induced protein carbonylation by detoxification process. The transgenics also showed higher activity of delta 1-pyrroline-5- carboxylate synthase (P5CS) enzyme resulted in increasedproline levels to maintain osmotic homeostasis. The results demonstrates that the AKR1 protects proteins or enzymes that are involved in scavenging of cytotoxic compounds by detoxifying RCCs generated under salinity stress. © 2017 Elsevier Masson SA

A modified multisite gateway cloning strategy for consolidation of genes in plants

The genome information is offering opportunities to manipulate genes, polygenic characters and multiple traits in plants. Although a number of approaches have been developed to manipulate traits in plants, technical hurdles make the process difficult. Gene cloning vectors that facilitate the fusion, overexpression or down regulation of genes in plant cells are being used with various degree of success. In this study, we modified gateway MultiSite cloning vectors and developed a hybrid cloning strategy which combines advantages of both traditional cloning and gateway recombination cloning. We developed Gateway entry (pGATE) vectors containing attL sites flanking multiple cloning sites and plant expression vector (pKM12GW) with specific recombination sites carrying different plant and bacterial selection markers. We constructed a plant expression vector carrying a reporter gene (GUS), two Bt cry genes in a predetermined pattern by a single round of LR recombination reaction after restriction endonuclease-mediated cloning of target genes into pGATE vectors. All the three transgenes were co-expressed in Arabidopsis as evidenced by gene expression, histochemical assay and insect bioassay. The pGATE vectors can be used as simple cloning vectors as there are rare restriction endonuclease sites inserted in the vector. The modified multisite vector system developed is ideal for stacking genes and pathway engineering in plants. © 2012 Springer Science+Business Media, LLC