Biochemical and molecular analyses of copper–zinc superoxide dismutase from a C4 plant Pennisetum glaucum reveals an adaptive role in response to oxidative stress

Mahanty, Srikrishna; Kaul, Tanushri; Pandey, Prachi; Reddy, Ramesha A.; Mallikarjuna, G. B.; Reddy, Chinreddy S.; Sopory, Sudhir K.; Reddy, Malireddy K.

doi:10.1016/j.gene.2012.06.001

Cited by 27 publications

(16 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A possible link between copper homeostasis and stress responses are the superoxide dismutases, considered to have an important function in different abiotic stress responses (Gill et al ., ). Elevated levels of copper/zinc superoxide dismutase were shown to enhance salinity tolerance (Prashanth et al ., ; Jing et al ., ), to improve plant resistance to oxidative stress conditions (Kwon et al ., ; Sunkar et al ., ; Tang et al ., ; Prashanth et al ., ; Mahanty et al ., ; Xu et al ., ) and to improve tolerance to low‐temperature stress (Gupta et al ., ; McKersie et al ., ). Both the expression and activity of superoxide dismutases are affected by copper availability, as shown by the effect of different mutations which affect copper homeostasis (Cohu and Pilon, ; Huang et al ., ; Boutigny et al ., ).…”

Section: Discussionmentioning

confidence: 99%

miR408 is involved in abiotic stress responses in Arabidopsis

2015

View full text Add to dashboard Cite

SUMMARYMicroRNAs (miRNAs) are small RNAs that regulate the expression of target genes post-transcriptionally; they are known to play major roles in development and responses to abiotic stress. miR408 is a highly conserved miRNA in plants that responds to the availability of copper and targets genes encoding copper-containing proteins. It was recently recognized to be an important component of the HY5-SPL7 gene network that mediates a coordinated response to light and copper, illustrating its central role in the response of plants to the environment. Expression of miR408 is significantly affected by a variety of developmental and environmental conditions; however, its biological function is unknown. Involvement of miR408 in the abiotic stress response was investigated in Arabidopsis. Expression of miR408, as well as its target genes, was investigated in response to salinity, cold, oxidative stress, drought and osmotic stress. Analyses of transgenic plants with modulated miR408 expression revealed that higher miR408 expression leads to improved tolerance to salinity, cold and oxidative stress, but enhanced sensitivity to drought and osmotic stress. Cellular antioxidant capacity was enhanced in plants with elevated miR408 expression, as manifested by reduced levels of reactive oxygen species and induced expression of genes associated with antioxidative functions, including Cu/Zn superoxide dismutases (CSD1 and CSD2) and glutathione-S-transferase (GST-U25), as well as auxiliary genes: the copper chaperone CCS1 and the redox stress-associated gene SAP12.Overall, the results demonstrate significant involvement of miR408 in abiotic stress responses, emphasizing the central function of miR408 in plant survival.

show abstract

Section: Discussionmentioning

confidence: 99%

miR408 is involved in abiotic stress responses in Arabidopsis

2015

View full text Add to dashboard Cite

show abstract

“…For oxidative stress treatment assays, leaf strips of 2 cm length and uniform width from flag leaf of mature T 2 generation transgenic lines along with the control plants were incubated in 10 μM methyl viologen (MV; paraquat) for 6 h under dark at 28°C to allow diffusion of MV into the tissue and then exposed to 4 h of sunlight (Mahanty et al, 2012 ). The total chlorophyll content after MV treatment was determined spectrophotometrically following the protocol of Hiscox and Israelstam ( 1979 ).…”

Section: Methodsmentioning

confidence: 99%

Concurrent Overexpression of OsGS1;1 and OsGS2 Genes in Transgenic Rice (Oryza sativa L.): Impact on Tolerance to Abiotic Stresses

et al. 2018

View full text Add to dashboard Cite

Glutamine synthetase (GS) is a key enzyme involved in the nitrogen metabolism of higher plants. Abiotic stresses have adverse effects on crop production and pose a serious threat to global food security. GS activity and expression is known to be significantly modulated by various abiotic stresses. However, very few transgenic overexpression studies of GS have studied its impact on abiotic stress tolerance. GS is also the target enzyme of the broad spectrum herbicide Glufosinate (active ingredient: phosphinothricin). In this study, we investigated the effect of concurrent overexpression of the rice cytosolic GS1 (OsGS1;1) and chloroplastic GS2 (OsGS2) genes in transgenic rice on its tolerance to abiotic stresses and the herbicide Glufosinate. Our results demonstrate that the co-overexpression of OsGS1;1 and OsGS2 isoforms in transgenic rice plants enhanced its tolerance to osmotic and salinity stress at the seedling stage. The transgenic lines maintained significantly higher fresh weight, chlorophyll content, and relative water content than wild type (wt) and null segregant (ns) controls, under both osmotic and salinity stress. The OsGS1;1/OsGS2 co-overexpressing transgenic plants accumulated higher levels of proline but showed lower electrolyte leakage and had lower malondialdehyde (MDA) content under the stress treatments. The transgenic lines showed considerably enhanced photosynthetic and agronomic performance under drought and salinity stress imposed during the reproductive stage, as compared to wt and ns control plants. The grain filling rates of the transgenic rice plants under reproductive stage drought stress (64.6 ± 4.7%) and salinity stress (58.2 ± 4.5%) were significantly higher than control plants, thereby leading to higher yields under these abiotic stress conditions. Preliminary analysis also revealed that the transgenic lines had improved tolerance to methyl viologen induced photo-oxidative stress. Taken together, our results demonstrate that the concurrent overexpression of OsGS1;1 and OsGS2 isoforms in rice enhanced physiological tolerance and agronomic performance under adverse abiotic stress conditions, apparently acting through multiple mechanistic routes. The transgenic rice plants also showed limited tolerance to the herbicide Glufosinate. The advantages and limitations of glutamine synthetase overexpression in crop plants, along with future strategies to overcome these limitations for utilization in crop improvement have also been discussed briefly.

show abstract

“…Basu et al (2001) demonstrated that transgenic Brassica plants overexpressing mitochondrial MnSOD showed increased resistance to Al toxicity. Mahanty et al (2012) also reported that overexpression of Cu/ZnSOD enhanced tolerance against oxidative stress. pekinensis cv.…”

Section: Enzymatic Antioxidantsmentioning

confidence: 94%