关键词: 柑橘属, SAUR 基因家族, 基因表达, 全基因组鉴定

Abstract: Small auxin up-regulated RNA（SAUR）gene family plays a vital role in plant growth and development. In this study，a total of 70，69，58 and 62 SAUR homologous genes were identified from the genomes of Citrus clementina，C. medica，C. reticulata‘Mangshan’and C. maxima，respectively. Chromosomal location analysis revealed that the distribution of SAUR genes on chromosome is not uniform. Most of SAUR genes appeared as tandem duplication clustered on chromosome. The tandem duplication and segmental duplication could be the consequence of SAUR genes expansion. Most of citrus SAUR genes do not contain intron，and possess highly conserved four SAUR-specific motifs. The phylogenetic analysis displayed that 629 SAUR genes from 5 species were classified into 9 groups. In each group，the majority of species-specific SAUR genes have a close genetic relationship. cis-elements analysis revealed that light responsiveness，transcription factor（TF）binding，hormone responsiveness，wound responsiveness，low temperature responsiveness，zein metabolism and flavonoid biosynthesis related elements exist in upstream sequences of CclSAUR genes. The results of qRT-PCR analysis indicated that the expression of most of CclSAUR genes clearly responded to the exogenous IAA and cold temperature treatments. This study presented an overview information of constitution，structure and basic biological function of SAUR gene family in different citrus species.

Key words: Citrus, small auxin up-regulated RNA, gene expression, genome-wide analysis