Model analysing the antioxidant responses of leaves and roots of switchgrass to NaCl-salinity stress

Salinity is a major environmental stress and a substantial constraint on plant production. The objective of this research was to better understand the mechanisms of the antioxidant responses of leaves and roots to NaCl-salinity stress in switchgrass (Panicum virgatum L.). The effects of NaCl-salinity stress (1, 3, 5, 10 and 15 g NaCl/kg dry soil) on lipid peroxidation and antioxidant defences in switchgrass leaves and roots were investigated, and a model analysis was conducted. The results of the correlation analyses indicated that CAT, POD and SOD were more important than APX, GSH and MDA, whereas the model analyses suggested that the latter three biochemical indices were more sensitive than the former three indices to NaCl-salinity in switchgrass. The connective models of APX, GSH, MDA, CAT, SOD and POD between leaves and roots were obtained, respectively. The new models can be used to closely predict the biochemical index values in switchgrass roots or leaves.

► The antioxidant responses to salinity stress in switchgrass are investigated.
► NaCl-salinity stress caused membrane lipid peroxidation in switchgrass.
► The sensitivity of the six biochemical indices to NaCl-salinity was ordered.
► The anti-oxidative responses were under the relative adjusting mechanism.