钩藤光敏色素互作因子鉴定及其表达分析

Identification of phytochrome-interacting factors and their expression analysis in Uncaria rhynchophylla

光敏色素互作因子(phytochrome-interacting factors,PIFs)是具有基本螺旋-环-螺旋(bHLH)结构域的转录因子,它们与光敏色素相互作用,在光信号转导过程发挥重要作用。基于转录组数据注释及蛋白同源比对,共筛选出28个钩藤PIF家族成员(UrPIFs),编码蛋白的长度在420~741个氨基酸之间,理论分子量46.47~79.46 kDa;等电点5.97~9.15。亚细胞定位预测结果显示UrPIFs均位于细胞核。系统进化关系和保守基序分析表明,28个UrPIFs分为4组,都具有活性光敏色素B结合(active phytochrome B-binding,APB)结构域和bHLH结构域,而且每组成员之间具有相似的保守基序。组织表达谱显示多数UrPIFs在叶中表达量较高,其次是茎,最低的是根。在遮光条件下,除UrPIF05外,7个UrPIFs表达量呈上升趋势;转移至正常光照条件后,8个Ur PIFs的表达量均呈下降趋势。尤其是UrPIF15对光较为敏感,可能在光信号转导中发挥重要作用。UrPIFs的鉴定和分析可为进一步构建钩藤光调控网络提供参考。

Phytochrome-interacting factors(PIFs),as the basic helix-loop-helix(bHLH) transcription factors,are the primary signaling partners for phytochromes(PHY) that play a key role in PHY-mediated light signal transduction.Based on the annotation of Uncaria rhynchophylla transcriptome data and protein homology alignment,a total of 28 U.rhynchophylla PIFs(UrPIFs) were screened,which encoded proteins between 420 and 741 amino acids,and the theoretical molecular weight was 46.47 kDa to 79.46 kDa,and the isoelectric point was 5.97 to 9.15.Subcellular localization showed that all UrPIFs were located in the nucleus.Phylogenetic relationships and conserved motifs analysis showed that the 28 UrPIFs were divided into four groups,all of which possessed active phytochrome B-binding(APB) motif and bHLH structural domains,and each members of the group had similar conserved motifs.Tissue expression profiles showed that most Ur PIFs were highly expressed in leaves,followed by stems,and the lowest was roots.Under shading conditions,the expression of seven Ur PIFs tended to increase,except Ur PIF05.After shifting U.rhynchophylla to normal light conditions,the expression levels of the eight Ur PIFs tended to decrease.In particular,Ur PIF15 was more sensitive to light and may play an important role in light signal transduction.The identification and analysis of Ur PIFs could provide a reference for the further construction of light regulation networks of U.rhynchophylla.