Effects of Iron Deficiency Stress on Plant Growth and Quality in Flowering Chinese Cabbage and Its Adaptive Response

Abstract

Iron (Fe) plays an important role in the growth and development of the human body and plants. The effects of different Fe concentrations, 1-aminocyclopropane-1-carboxylic acid (ACC), and cobalt chloride (Co2+) treatments on plant growth, quality and the adaptive response to Fe deficiency stress were investigated in flowering Chinese cabbage. The results revealed that Fe deficiency stress inhibited plant growth. The content of vitamin C (Vc), soluble protein, and soluble sugar in leaves and stalks were significantly reduced under Fe deficiency stress, while the content of cellulose and nitrate was increased. Meanwhile, Fe deficiency stress obviously reduced the net photosynthetic rate and nitrate reductase (NR) activity of leaves. The balance system of active oxygen metabolism was destroyed due to Fe deficiency, resulting in the decrease of catalase (CAT) activity, superoxide dismutase (SOD) activity of roots and leaves, and peroxidase (POD) activity of leaves, while POD activity in roots and malonaldehyde (MDA) content were significantly increased. The treatments of Fe deficiency and ACC significantly reduced pH value of the root medium, promoted release of ethylene, and increased Fe3+ reductase activity, while Co2+ treatment showed the results opposite to those of Fe deficiency and ACC treatments. Thus, Fe deficiency stress could induce nitrogen metabolism, photosynthesis, reactive oxygen metabolism, pH of root medium, and Fe3+ reductase activity that was related to physiological adaptive response and tolerance mechanisms. We also found that ethylene could involve in regulating the adaptive response to Fe deficiency stress and improve the availability of Fe in flowering Chinese cabbage.Main ConclusionFe deficiency stress could induce nitrogen metabolism, photosynthesis, reactive oxygen metabolism, pH of root medium, and Fe3+ reductase activity that was related to physiological adaptive response and tolerance mechanisms.