Characterization of the Populus Rab family genes and the function of PtRabE1b in salt tolerance

作   者：张进，李煜，刘伯斌，王丽娟，张利，胡建军，陈军，郑焕泉，卢孟柱
期刊名称：BMC Plant Biology
影响因子：3.930
卷 期 号：18
页     码：124
关键词：Populus, Rab GTPase, Phylogenetic analysis, Co-expression network, Subcellular localization, Salt tolerance
论文摘要：
Background: Rab proteins form the largest family of the Ras superfamily of small GTP-binding proteins and regulate
intracellular trafficking pathways. However, the function of the Rab proteins in woody species is still an open question.
Results: Here, a total of 67 PtRabs were identified in Populus trichocarpa and categorized into eight subfamilies
(RabA-RabH). Based on their chromosomal distribution and duplication blocks in the Populus genome, a total of
27 PtRab paralogous pairs were identified and all of them were generated by whole-genome duplication events.
Combined the expression correlation and duplication date, the PtRab paralogous pairs that still keeping highly
similar expression patterns were generated around the latest large-scale duplication (~ 13 MYA). The cis-elements
and co-expression network of unique expanded PtRabs suggest their potential roles in poplar development and
environmental responses. Subcellular localization of PtRabs from each subfamily indicates each subfamily shows a
localization pattern similar to what is revealed in Arabidopsis but RabC shows a localization different from their
counterparts. Furthermore, we characterized PtRabE1b by overexpressing its constitutively active mutant PtRabE1b(Q74L)
in poplar and found that PtRabE1b(Q74L) enhanced the salt tolerance.
Conclusions: These findings provide new insights into the functional divergence of PtRabs and resources for genetic
engineering resistant breeding in tree species.