Expression of the NF-YB21 Encoded Gene Confers Tolerance to Osmotic Stresses in .

Drought is the main environmental factor that limits the yield and quality of apples () grown in arid and semi-arid regions. Nuclear factor Ys (NF-Ys) are important transcription factors involved in the regulation of plant growth, development, and various stress responses. However, the function of genes is poorly understood in apples. Here, we identified 43 genes in the genome of apples and conducted an initial functional characterization of the apple . Expression analysis of members in revealed that a large number of were highly expressed in the roots compared with the leaves, and a large proportion of genes responded to drought treatment. Furthermore, heterologous expression of which was significantly upregulated by drought, led to a longer root length and, thus, conferred improved osmotic and salt tolerance in . Moreover, the physiological analysis of overexpression revealed enhanced antioxidant systems, including antioxidant enzymes and compatible solutes. In addition, genes encoding catalase (, ), superoxide dismutase (, , ), and peroxidase (, , , ) showed upregulated expression in the overexpression lines. These results for the gene family provide useful information for future studies on NF-Ys in apples, and the functional analysis of MsNF-YB21 supports it as a potential target in the improvement of apple drought tolerance via biotechnological strategies.