MbHY5-MbYSL7mediates chlorophyll synthesis and iron transport under iron deficiency in Malus baccata

Abstract

Iron (Fe) plays an important role in cellular respiration and catalytic reactions of metalloproteins in plants and animals. Plants maintain iron homeostasis through absorption, translocation, storage, and compartmentalization of iron <i>via</i> a cooperative regulative network. Here, we showed different physiological characteristics in the leaves and roots of <i>Malus baccata</i> under Fe sufficiency and Fe deficiency conditions and propose that <i>MbHY5</i> (elongated hypocotyl 5), an important transcription factor for its function in photomorphogenesis, participated in Fe deficiency response in both the leaves and roots of <i>M. baccata</i>. The gene co-expression network showed that <i>MbHY5</i> was involved in the regulation of chlorophyll synthesis and Fe transport pathway under Fe-limiting conditions. Specifically, we found that Fe deficiency induced the expression of <i>MbYSL7</i> in root, which was positively regulated by <i>MbHY5.</i> Overexpressing or silencing <i>MbYSL7</i> influenced the expression of <i>MbHY5</i> in <i>M. baccata.</i>