Identification and Expression Analysis of the Gene Family under Phytohormone and Abiotic Stresses in Apple ().

Ubiquitination participates in plant hormone signaling and stress response to adversity. SKP1-Like, a core component of the SCF (Skp1-Cullin-F-box) complex, is the final step in catalyzing the ubiquitin-mediated protein degradation pathway. However, the gene family has not been well characterized in response to apple abiotic stresses and hormonal treatments. This study revealed that 17 gene family members with the conserved domain of SKP1 were identified in apples and were unevenly distributed on eight chromosomes. The genes located on chromosomes 1, 10, and 15 were highly homologous. The genes were divided into three subfamilies according to the evolutionary affinities of monocotyledons and dicotyledons. members of the same group or subfamily show some similarity in gene structure and conserved motifs. The predicted results of protein interactions showed that members of the MdSKP1-like family have strong interactions with members of the F-Box family of proteins. A selection pressure analysis showed that genes were in purifying selection. A chip data analysis showed that and were higher in flowers, whereas was higher in fruits. The upstream -elements of genes contained a variety of elements related to light regulation, drought, low temperature, and many hormone response elements, etc. Meanwhile, qRT-PCR also confirmed that the gene is indeed involved in the response of the apple to hormonal and abiotic stress treatments. This research provides evidence for regulating gene expression in response to hormonal and abiotic stresses to improve apple stress resistance.