Glutathione and ascorbic acid protect Arabidopsis plants against detrimental effects of iron deficiency

Iron is an essential micronutrient required for a wide variety of cellular functions in plant growth and development. Chlorosis is the first visible symptom in iron-deficient plants. Glutathione (GSH) and ascorbic acid (ASC) are multifunctional metabolites playing important roles in redox balancing. In this work, it was shown that GSH and ASC treatment prevented chlorosis and the accumulation of reactive oxygen species induced by iron deficiency in Arabidopsis leaves. In iron deficiency, GSH and ASC increased the activity of the heme protein ascorbate peroxidase at a similar level to that found in iron-sufficient seedlings. GSH was also able to preserve the levels of the ironsulfur protein ferredoxin 2. GSH content decreased 25% in iron-deficient Arabidopsis seedlings, whereas the ASC levels were not affected. Taken together, these results showed that GSH and ASC supplementation protects Arabidopsis seedlings from iron deficiency, preserving cell redox homeostasis and improving internal iron availability.