Abstract:
【Objective】The member identification,phylogenetic analysis and stress response analysis of watermelon
OSCA gene family were carried out to provide reference for revealing the biological function and molecular mechanism of stress resistance of watermelon
OSCA gene.【Method】The members of watermelon
OSCA gene family were identified by bioinformatics method from watermelon genome database,and named according to chromosome location information. Chromosome position,gene structure,collinearity,promoter,protein structure and phylogeny of gene family members were analyzed comprehensively. Transcriptome data and qRT-PCR were used to analyze
OSCA gene expression in watermelon under stress.【Result】Watermelon
OSCA gene family had 10 members,which were unevenly distributed on 6 chromosomes. The molecular weight of watermelon OSCA protein varied from 24.59 to 91.97 kD,and the number of amino acids ranged from 214 to 809 aa,most of which were located in the plasma membrane. The results of collinearity analysis showed that the fragment replication event occurred during the evolution of watermelon
OSCA gene. The watermelon
OSCA gene family was divided into three groups,and the exon-intron composition pattern,conserved motif arrangement of protein,the number proportion of secondary structure and the tertiary structure model of the members of the same group were similar. The
OSCA genes of watermelon,rice,tomato and
Arabidopsis thaliana were divided into 6 subgroups,watermelon
OSCA gene was distributed in each subgroup. The promoter region of
OSCA gene in watermelon contained several abiotic stress response elements such as anaerobic induction,cold stress response,light response and drought stress response. Under drought,low temperature and salt stress,the expression levels of
OSCA gene family members in watermelon all changed to different degrees,and the expression levels of
ClaOSCA3 and
ClaOSCA5 all changed significantly under three different stress conditions(
P<0.05).【Conclusion】Watermelon
OSCA gene is conserved in the evolutionary process,and is closely related to
OSCA gene of A. thaliana,rice and tomato. Functional differentiation exists within the
OSCA gene family in watermelon,and
ClaOSCA3 and
ClaOSCA5 may be important stress resistance genes in the stress response mechanism.