LATERAL ORGAN BOUNDARIES DOMAIN (LBD) proteins, a plant-specific transcription factor family, play important roles in many aspects of plant development. It has been well-studied in Arabidopsis. However, little is known about LBD genes to date. Investigation of LBD genes at genome-wide level in legumes would likely provide new insights into the regulatory mechanisms of plant growth and development, especially, motor organs and compound leaves development.
Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) identified and characterized the LBD gene family on the genome-wide scale in Lotus japonicus and Medicago truncatula, both of which are used as model legumes due to their short life cycles, self-fertility, and relatively small diploid genome. They found 38 putative LBD genes in L. japonicus and 57 members in M. truncatula, respectively. They further characterized motif distribution, evolutionary relationship and expression profiles in detail.
They found that two LBD members LjLBD11 (LjLOB1) and LjLBD6 (LjLOB3, SLP1) were highly expressed in compound leaf and can form complex by proteins interaction, implying that they may work together in controlling compound leaf development in L. japonicus. Compared with other plants, L. japonicus and M. truncatula apparently harbored more LBD members in its genome, probably due to genome duplication that resulted in gene family expansion during evolution. All LBD proteins identified in the study contained a highly conserved CX2CX6CX3C zinc finger-like domain, implying its structural and functional necessity.
The gene structure, conserved motif, and phylogenetic analyses indicated that the functions of LBD genes are likely conserved among angiosperms. The expression patterns of LjLBD11 and its interaction with LjLBD6 provided the molecular basis for the mechanisms underlying LjLBD11gene in compound leaf development, motor organ specification in L. japonicus, even more generally in legumes.
The study entitled “Genome-Wide Identification, Evolutionary Analysis and Expression Profiles of LATERAL ORGAN BOUNDARIES DOMAIN Gene Family in Lotus japonicus and Medicago truncatula” has been published in PLoS ONE.
Contact
CHEN Jianghua, Ph.D Principal Investigator
Key Laboratory of Tropical Plant Resources and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, Yunnan, China
E-mail: jhchen@xtbg.ac.cn
Tel: +86 871 65163626
