| Floral transition is a critical and strictly regulated developmental process in plants. Mutations in Arabidopsis LIKE HETEROCHROMATIN PROTEIN I (AtLHP1) /TERMINAL FLOWER 2 (TFL2) result in early and terminal flowers. Little is known about the gene expression, function and evolution of plant LHP1 homologs, except for Arabidopsis LHPI. In this study, LHP1 expression patterns were compared among taxas that occupy pivotal economics positions in Poacea, and the conservation and divergence of plant LHPI protein sequences was analyzed by sequence alignments and phylogeny.Exprements suggested that OsLHP(rice, Oryza saliva japonica) did not expressed as ZmLHP1(maize, Zea mays L.), SoLHP1(sugarcane, Saccharum officinarum L.) and AtLHP1 did. They were mainly detected in actively deviding cells or in tissures of active differentiation. Although they might not function in the same way,.it would be a fact that they still work in maintaining identities of cells and tissues.Rice's leaves might capture enviorenmental clues,and turn on the floral transion machnism, which lift the OsLHP transcriptional level up. When the translation and the after-translation modifications finished, OsLHP1 proteins may be transffered to the active cells or tissues, in which they are involved in the manipulation of rice development.Plant LHP1 homologs are more conserved than previously expected.Several relatively conserved new motifs/regions such as conserved CSD region (CCR) and conserved NLS3 region(CNR) were identified among LHP1 homologs. Phylogeny of plant LHP1 proteins agreed with established angiosperm relationships. "Unequal cross-over" might have contributed to the divergence in the N-terminal and hinge region (HR) lengths of LHP1 homologs, which plays an important role in the evolution of LHP1. With evolving from moss to angiosperms, the length of HR becomes shorter, which may suggest the existence of a special evolution mechnism of LHP1. By the alingnments of LHP1, so many insertions and deletions were identified in GmLHP1s(soybean) that we propose an "insertion-deletion" model for soybean(Glycine max L.) GmLHP1s evolution. |
