Cloning And Expression Analysis Of HD2 Subfamily Genes From Populus Alba×Populus Gllandulosa

Epigenetics is a hotspot in the research of the biology, and histone modification is an important part of the study of epigenetics. In this study, three genes in HD2 sub-family were cloned from populus 84K(Populus alba-X Populus gllandulosa). Sequences of the three HD2 proteins were analyzed by bioinformatics methods. The results showed that 84kHD2 family genes encoding three proteins and the length of each protein was 276aa,274 aa and 276 aa, respectively. Hydrophobicity analysis showed that the family proteins were hydrophilic proteins. Conserved domain analysis showed that the C terminal parts of the three proteins had a typical structure of zinc finger, possibly associated with the binding to chromosome DNA. Protein secondary structure analysis showed that the HD2 proteins did not have alpha helix, only had beta folding and random coil.Transmembrane analysis also showed that these protein did not contain transmembrane regions. Subcellular localization analysis showed that the three family members were located in the nucleus. Gene expression analysis showed that the three genes were expressed in the organs examined but with different expression levels. The three genes were highly expressed in leaves, but with low levels in roots. Real-time PCR analysis showed that the three genes in HD2 subfamily were regulated by salt, drought and cold. Generally speaking, the genes were repressed after salt and drought treatments, though the genes were slightly increased after short-term treatments. For cold stress treatment, the genes were u-pregulated especially after short-term cold treatment. The expression patterns of HDT901 and HDT902 were similar, but diiferent from HDT903.