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In plants, ferritin proteins play an important role in iron (Fe) storage which contributes to plant growth and development. However, the biological functions of ferritins in fruit trees are essentially unknown. In this study, three Ferritin genes were isolated from 'Zhentong No. 3' peach, which were named PpFer1-PpFer3. The expression levels of these genes were different in distinct tissues/organs. Notably, PpFer1 was the most abundantly expressed Ferritin family gene in all tested tissues of 'Zhentong No. 3' peach; its expression levels were significantly enhanced throughout the entire peach seedling under Fe toxicity and H2O2 stress, particularly in the leaves. In addition, over-expression of PpFer1 was effective in rescuing the retarded growth of Arabidopsis fer1-2 knockout mutant, embodied in enhanced fresh weight, primary root length, lateral root numbers, total root length, total leaf chlorophyll, stomatal conductance (Gs), net photosynthetic rate (Pn), transpiration rate, and tissue Fe concentration. This study provides insights into understanding the molecular mechanisms of Fe storage and sequestration in perennial fruit trees. [ABSTRACT FROM AUTHOR]

Shaker-type K+ channels are critical for plant K+ acquisition and translocation that play key roles during plant growth and development. However, molecular mechanisms towards K+ channels are extremely rare in fruit trees, especially in peach. In this study, we identified 7 putative shaker-type K+ channel genes from peach, which were unevenly distributed on 5 chromosomes. The peach shaker K+ channel proteins were classified into 5 subfamilies, I-V, and were tightly clustered with pear homologs in the phylogenetic tree. Various cis-acting regulatory elements were detected in the promoter region of the shaker-type K+ channel genes, including phytohormone-responsive, abiotic stress-responsive, and development regulatory elements. The peach shaker K+ channel genes were expressed differentially in distinct tissues, and PpSPIK was specifically expressed in the full-bloom flowers; PpKAT1 and PpGORK were predominantly expressed in the leaves, while PpAKT1, PpKC1, and PpSKOR were majorly expressed in the roots. The peach shaker K+ channel genes were differentially regulated by abiotic stresses in that K+ deficiency, and ABA treatment mainly increased the shaker K+ channel gene expression throughout the whole seedling, whereas NaCl and PEG treatment reduced the shaker K+ channel gene expression, especially in the roots. Moreover, electrophysiological analysis demonstrated that PpSKOR is a typical voltage-dependent outwardly rectifying K+ channel in peach. This study lays a molecular basis for further functional studies of the shaker-type K+ channel genes in peach and provides a theoretical foundation for K+ nutrition and balance research in fruit trees. [ABSTRACT FROM AUTHOR]