Confers Iron Homeostasis Under Iron Deficiency in .

Iron stress adversely impacts plants' growth and development. Transcription factors (TFs) receive stress signals and modulate plant tolerance by influencing the expression of related functional genes. In the present study, we investigated the role of an apple bHLH transcription factor in the tolerance to iron stresses. The expression of was induced significantly by low-iron and high-iron treatments and -overexpressed plants displayed iron-stress-tolerant phenotypes. A determination of physiological and biochemical indexes associated with abiotic stress responses showed that overexpression of increased the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in plants treated with iron stress, and decreased the contents of HO and malondialdehyde (MDA), which contribute to reduce cell membrane lipid peroxidation. Meanwhile, the accumulation of proline in transgenic plant cells increased, regulating cell osmotic pressure. Furthermore, quantitative expression analysis indicated that overexpression of improved the expression levels of positive functional genes' responses to iron stress, improving plant resistance. Interestingly, may have the ability to balance the homeostasis of iron and other metal ions for the iron homeostasis of cell under low-iron environments. This research demonstrates that is a key regulator of cell iron homeostasis in plants under iron deficiency, providing new knowledge for plant resistance regulation.