Abstract:
【Objective】To identify rice
WOX family gene members and to analyze expression of seeds germinated under stress, so as to provide theoretical reference for exploring function of
WOX family genes, mechanism, rice genetic improvement.【Method】
WOX family genes were identified. Their phylogenetic evolution relation, physicochemical properties, gene structures, conserved domains, conserved motifs, cis-acting elements, and chromosomal localization were analyzed. Their temporal and spatial expression characteristics and expression patterns under abiotic stress during seed germination were determined through qRT-PCR.【Result】Thirteen rice
WOX family gene members(
OsWOX1-
OsWOX13) were obtained from identification of PlantTFDB data base and they could be divided into 3 branches, in which only 1 belonged to ancient evolutionary branch and 6 intermediate evolutionary branch and 6 modern evolutionary branch. Thirteen genes of
OsWOXs family distributed unevenly in chromosome No.1, 3, 4, 5, 7, 8, 11. The rest 5 chromosome did not contain genes from this family. Gene structure differed greatly, indicating
WOX gene function had difference and diversity. Thirteen rice WOX proteins located in cell nucleus, with Homodomain superfamily conserved domains and 10 conserved motifs, in which Motif 1 and Motif 2 located in every protein's conserved functional domains. The promoter regions of
OsWOXs genes contained more light response elements and defense stress response elements, and seed-specific response elements(RY-element) existed in
OsWOX1, OsWOX9, OsWOX11 and
OsWOX12 genes. The expression patterns of 13
OsWOXs genes were significantly different under rice seed germination and stress. The expression of
OsWOX8 gene was high in germinating seeds and seedlings, the expression of
OsWOX9 and
OsWOX11 genes was high in germinating seeds and the expression of
OsWOX2, OsWOX6 and
OsWOX8 genes was high in seedlings. Under drought stress, the relative expression of
OsWOX1, OsWOX2, OsWOX4 and
OsWOX5 genes in seedlings were 15.0 times, 8.0 times, 3.9 times and 3.6 times higher than those in the control(CK) group, respectively, while the relative expression levels of
OsWOX3, OsWOX4 and
OsWOX7 genes in seeds were 87.2%, 86.9% and 97.8% lower than those in the CK group, respectively.【Conclusion】
OsWOXs gene family members are relatively advanced in phylogeny compared to that in
Arabidopsis thaliana and corn, and only
OsWOX8 is retained as the only ancient branch.
OsWOXs family genes contain lots of light response and stress response elements, which may be more involved in photosynthesis and stress response.
OsWOXs gene showed abundant and diverse expression patterns of in rice seed germination, seedling stage and various abiotic stresses and
OsWOX9 and
OsWOX11 were the key genes regulating seed germination.