Genome-Wide Identification of the Ginkgo ( L.) Transcription Factor Gene and Characterization of Its Expression.

Lateral organ boundaries domain (LBD) proteins are plant-specific transcription factors involved in various transcriptional regulation processes. We identified a total of 37 genes in ginkgo, and based on gene structure and phylogenetic analysis, the gene family was classified into class I (33, with the largest number of Id genes (16)) and class II (4). The ginkgo gene was also analyzed regarding its chromosomal distributions, gene duplications, promoters, and introns/exons. In addition, gene expression profiling and real-time quantitative PCR analysis showed that the expression of 14 genes differed in six different tissues and three developmental stages. The gene of class II were highly expressed relative to the class I gene in all tissues and developmental stages, while class Id gene were generally at low levels or were not expressed, especially in seed developmental stages. The expression pattern analysis of cold/drought treatment and IAA/ABA hormone treatment showed that abiotic stress treatment could significantly induce the expression of gene, of which class II genes played a key role in stress treatment. Our study provides a solid foundation for further evolutionary and functional analysis of the ginkgo gene family.