Overexpressing ATP Sulfurylase Improves Fe-Deficiency Tolerance in Apple Calli and Tobacco

Abstract

Iron (Fe) deficiency is one of the most common micronutrient deficiencies limiting crop production globally, especially in arid regions due to decreased availability of Fe in alkaline soils. The ATP sulfurylase (ATPS) gene has been reported to participate in regulating various abiotic stresses. Transcriptome data and qRT-PCR analysis revealed that the ATP sulfurylase gene MhATPS1 was notably induced by Fe-deficiency stress. Consequently, MhATPS1 (103410737) was isolated from Malus halliana, and transgenic tobacco and transgenic apple calli were successfully obtained by genetic transformation. Compared with the wild type (WT), transgenic MhATPS1 lines (transgenic tobacco and transgenic apple calli) displayed stronger resistance to Fe-deficiency treatment. To be specific, transgenic plants exhibited better growth, accumulated more Fe2+ content, had higher ferric chelate reductase (FCR) activity, and a greater active oxygen scavenging capacity. Furthermore, transgenic MhATPS1 lines up-regulated the expression of Fe uptake genes under Fe-deficit stress. Additionally, MhATPS1 transgenic lines secreted more H+ content compared to the WT. In summary, these findings indicate that the MhATPS1 gene may play a positive role in Fe-deficiency stress in both tobacco and apple calli.

Keywords

• <i>ATP sulfurylase</i>
• molecular cloning
• functional identification
• Fe-deficiency stress