BACKGROUND Escherichia coli suffer from osmotic stress during succinic acid (SA) production, which reduces the performance of this microbial factory. RESULTS Here, we report that a point mutation leading to a single amino acid change (D654Y) within the β-subunit of DNA-dependent RNA polymerase (RpoB) significantly improved the osmotolerance of E. coli. Importation of the D654Y mutation of Rpo...

Nitric oxide (NO) is a active molecule involved in mediation of various biotic and abiotic stressinduced physiological responses in plants. In the present study, using SNP (sodium nitroprusside) as NO donor and cPTIO [2-(4-carboxypheny-4,4,5,5-tetramethylimidazoline-1-1oxyl-3-oxide, potassium salt] as specific NO scavenger, we examined the ability of exogenous NO to alleviate oxidative damage, ...

The glycerol metabolic pathway is a special cycle way; glycerol-3-phosphate dehydrogenase (G3pdh), glycerol-3-phosphate phosphatase (G3pp), dihydroxyacetone reductase (Dhar), and dihydroxyacetone kinase (Dhak) are the key enzymes around the pathway. Glycerol is an important osmolyte for Dunaliella salina to resist osmotic stress. In this study, comparative activities of the four enzymes in D. s...

Abscisic acid (ABA) catabolism is one of the determinants of endogenous ABA levels affecting numerous aspects of plant growth and abiotic-stress responses. The major ABA catabolic pathway is triggered by ABA 8'-hydroxylation catalysed by ABA 8'-hydroxylase, the cytochrome P450 CYP707A family. In this study, the full-length cDNAs of AhCYP707A1 and AhCYP707A2 were cloned and characterized from pe...

Osmotic and oxidative stress responses to iso-osmotic (-0.4 Mpa) NaCl, PEG-6000 and mannitol stress were studied in 15-day old plants of three potato cultivars viz. ‘Kufri Kufri Bahar’ ‘Jyoti’ and ‘Chandramukhi’. After 2-weeks of treatment, plants were analyzed for biochemical and physiological determinants of stress. Relative water content (RWC) and membrane damage rate (MDR) were significantl...

When a strain of Escherichia coli, expressing a hybrid protein GalK-beta-Gal, is shifted to high osmolarity, the beta-galactosidase activity strongly decreases within 20 min of shock. The loss of beta-galactosidase activity results from degradation of the hybrid protein under osmotic stress. The results raise the possibility that osmotic stress induces a specific osmodependent protease.