Characterization of the Populus Rab family genes and the function of PtRabE1b in salt tolerance.
Jin Zhang, Yu Li, Bobin Liu, Lijuan Wang, Li Zhang, Jianjun Hu, Jun Chen, Huanquan Zheng, Mengzhu Lu
Author Information
Jin Zhang: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China. ORCID
Yu Li: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Bobin Liu: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Lijuan Wang: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China. wlj307@caf.ac.cn.
Li Zhang: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Jianjun Hu: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Jun Chen: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Mengzhu Lu: State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China. lumz@caf.ac.cn.
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.
