Identification and expression analysis of the SKP1-like gene family under phytohormone and abiotic stresses in apple (Malus domestica)

Abstract

Abstract Background Ubiquitination participated 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 SKP1-Like gene family has not been well characterized in response to abiotic stresses and hormonal treatments in apple. Results Our study revealed that 17 MdSKP1-Like gene family members with conserved domain of SKP1 were identified in apples and were unevenly distributed on eight chromosomes. And the MdSKP1-Like genes located on chromosomes 1, 10 and 15 were highly homologous. The MdSKP1-like genes were divided into 2 subfamilies according to the evolutionary affinities of monocotyledons and dicotyledons. MdSKP1-like members of the same group or subgroup show some similarity in gene structure and conserved motifs. The predicted results of protein interactions showed that members of the MdSKP1 class family have strong interactions with members of the F-Box family of proteins. Selection pressure analysis showed that MdSKP1-Like gene were in purifying selection. Tissue-specific expression analysis showed that most MdSKP1-Like gene family members were highly expressed in flowers and leaves. We also found that the upstream cis-elements of MdSKP1-Like genes contained a variety of elements related to light regulation, drought, low temperature, many hormone response elements, etc. Thus, qRT-PCR also confirmed that the MdSKP1-Like gene is indeed involved in the response of apple to hormonal and abiotic stress treatments. Conclusions Our research provides some theories for regulating MdSKP1-Like gene expression in response to hormonal and abiotic stresses to improve stress resistance in apples.