Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5532419 | Flora - Morphology, Distribution, Functional Ecology of Plants | 2016 | 9 Pages |
â¢D. bipinnata is a C4 grass distributed in arid-saline lands of the subtropics.â¢Information about salinity tolerance of this species is not available.â¢This species can grow at 200 mM NaCl by combating oxidative stress.â¢Growth substantially declined at high salinity due to high ion toxicity that compromises the photosynthetic and antioxidant system.
Desmostachya bipinnata is a C4 grass distributed in arid-saline lands of the subtropical region. There are many economic usages of this perennial grass ranging from folk-medicine to cattle-fodder. However, information regarding the mechanism of salinity tolerance of this species is rare. This study examines the effects of salinity (0, 200 and 400Â mM NaCl) on growth, osmotic relations, photosynthesis and antioxidant defense. Salinity caused progressive decrease in fresh weight; however, dry weight decreased only at 400Â mM NaCl. Leaf sap osmotic potential and xylem pressure potential decreased while quantities of ash, proline and sugars increased in response to salinity increments. Stomatal conductance, photosynthetic CO2 gain and transpiration decreased with increasing salinity, while intercellular CO2 levels remained unaffected. Maximum and actual quantum yield of PS II and electron transport rate were inhibited with enhanced non-photochemical quenching under high salinity. Levels of superoxide dismutase and total phenols increased, those of guaiacol peroxidase and ascorbate peroxidase remained unaltered and catalase increased transiently at 200Â mM NaCl. Leaf hydrogen peroxide and malondialdehyde content increased with salinity. Our data suggest that D. bipinnata could maintain photosynthesis and manage oxidative stress at moderate salinity but a further increase in salinity compromised both photosynthesis and the antioxidant system.