Genome-wide identification and expression pattern analysis under drought stress of PHD family genes in alfalfa (Medicago sativa)
摘要
Alfalfa (Medicago sativa) is a perennial high-quality legume forage widely cultivated worldwide, but drought stress severely restrict its growth and development. Plant homeodomain finger (PHD) family genes are a type of zinc finger transcription factors widely distributed in eukaryotes. They act as histone code identifier to regulate the expression of downstream genes and play important biological roles in plant growth, development, and stress response. However, information about the PHD family genes in alfalfa remains limited at present.
ResultsWe identified 56 MsPHD genes containing 67 PHD domains in the alfalfa, and these genes were unevenly distributed on 8 chromosomes of alfalfa. There are 9 pairs of gene fragment duplicates in the MsPHD family. The 56 MsPHD genes are evolutionarily divided into 14 subgroups. There are differences in the conservative motifs and gene structure composition patterns of MsPHD among different subgroups. In addition, we identified 11 MsPHD genes related to drought stress, and their promoter regions all contained elements related to stress response. Quantitative Real-time PCR (QRT-PCR) further verified that the expression levels of these 11 MsPHD genes were significantly up-regulated in both roots and leaves, with MsPHD9 showing the highest upregulation. 57.14% of MsPHD proteins were predicted to be located in the nucleus, and the co-localization analysis of MsPHD9 protein confirmed that it was primarily located in the nucleus.
ConclusionsThe identification of alfalfa PHD family genes not only provides important genetic resources for in-depth analysis of the molecular mechanism of alfalfa drought resistance, but also lays a foundation for creating new germplasm of alfalfa with strong drought resistance through genetic engineering technology.