title: Genome-wide expansion and expression divergence of the basic leucine zipper transcription factors in higher plants with an emphasis on sorghum.
abstract: Plant bZIP transcription factors play crucial roles in multiple biological processes. However, little is known about the sorghum bZIP gene family although the sorghum genome has been completely sequenced. In this study, we have carried out a genome-wide identification and characterization of this gene family in sorghum. Our data show that the genome encodes at least 92 bZIP transcription factors. These bZIP genes have been expanded mainly by segmental duplication. Such an expansion mechanism has also been observed in rice, arabidopsis and many other plant organisms, suggesting a common expansion mode of this gene family in plants. Further investigation shows that most of the bZIP members have been present in the most recent common ancestor of sorghum and rice and the major expansion would occur before the sorghum-rice split era. Although these bZIP genes have been duplicated with a long history, they exhibited limited functional divergence as shown by nonsynonymous substitutions (Ka)/synonymous substitutions (Ks) analyses. Their retention was mainly due to the high percentages of expression divergence. Our data also showed that this gene family might play a role in multiple developmental stages and tissues and might be regarded as important regulators of various abiotic stresses and sugar signaling.
authors.affiliation: Institute of Botany and Temasek Life Sciences Laboratory Joint Research & Development Laboratory, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Jizhou
authors.initials: J
authors.lastname: Wang
authors.forename: Junxia
authors.initials: J
authors.lastname: Zhou
authors.forename: Baolan
authors.initials: B
authors.lastname: Zhang
authors.forename: Jeevanandam
authors.initials: J
authors.lastname: Vanitha
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Ramachandran
authors.forename: Shu-Ye
authors.initials: SY
authors.lastname: Jiang
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D018745:Genome, Plant / Q000235:genetics*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D045868:Sorghum / Q000235:genetics / Q000378:metabolism*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors