Effects of exogenous spermine on chlorophyll fluorescence, antioxidant system and ultrastructure of chloroplasts in Cucumis sativus L. under salt stress

Sheng Shu, Ling-Yun Yuan, Shi-Rong Guo, Jin Sun, Ying-Hui Yuan
Plant Physiology and Biochemistry: PPB 2013, 63: 209-16
The effects of exogenous spermine (Spm) on plant growth, chlorophyll fluorescence, ultrastructure and anti-oxidative metabolism of chloroplasts were investigated in Cucumis sativus L. under NaCl stress. Salt stress significantly reduced plant growth, chlorophylls content and F(v)/F(m). These changes could be alleviated by foliar spraying with Spm. Salt stress caused an increase in malondialdehyde (MDA) content and superoxide anion [Formula: see text] generation rate in chloroplasts. Application of Spm significantly increased activities of superoxidase dismutase (SOD, EC, peroxidase (POD, EC, and ascorbate peroxidase (APX, EC which decreased the levels of [Formula: see text] and MDA in the salt-stressed chloroplasts. Salt stress decreased the activities of dehydroascorbate reductase (DHAR, EC and glutathione reductase (GR, EC in the chloroplasts and reduced the contents of dehydroascorbate (DAsA) and glutathione (GSH), but increased monodehydroascorbate reductase (MDAR, EC activity. On the other hand, Spm significantly increased the activities of antioxidant enzymes and levels of antioxidants in the salt-stressed chloroplasts. Further analysis of the ultrastructure of chloroplasts indicated that salinity induced destruction of the chloroplast envelope and increased the number of plastoglobuli with aberrations in thylakoid membranes. However, Spm application to salt-stressed plant leaves counteracted the adverse effects of salinity on the structure of the photosynthetic apparatus. These results suggest that Spm alleviates salt-induced oxidative stress through regulating antioxidant systems in chloroplasts of cucumber seedlings, which is associated with an improvement of the photochemical efficiency of PSII.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"