The complete chloroplast genome of Zingiber striolatum Diels (Zingiberaceae).

The chloroplast genome of Zingiber striolatum Diels was sequenced using the MGI paired-end sequencing method and assembled. The chloroplast genome was 163,711 bp in length, containing a large single-copy (LSC) region of 88,205 bp, a small single-copy (SSC) region of 15,750 bp, and two inverted repeat (IR) regions of 29,752 bp. The overall GC content was 36.1%, whereas the corresponding value in the IR regions was 41.1%, which was higher than that in the LSC region (33.8%) and SSC region (29.6%). A total of 136 complete genes were annotated in the chloroplast genome of Z. striolatum, including 87 protein-coding genes (79 protein-coding gene species), 40 tRNA genes (29 tRNA species), and 8 rRNA genes (4 rRNA species). A phylogenetic tree was constructed using the maximum likelihood (ML) method, and the results showed that the phylogeny of Zingiber was well resolved with high support values, and Z. striolatum was sister to Z. mioga. The assembly and sequence analysis of the chloroplast genome can provide a basis for developing high-resolution genetic makers.

Genome-Wide Identification, Characterization, and Expression Analysis of GRAS Gene Family in Ginger (Zingiber officinale Roscoe).

GRAS family proteins are one of the most abundant transcription factors in plants; they play crucial roles in plant development, metabolism, and biotic- and abiotic-stress responses. The GRAS family has been identified and functionally characterized in some plant species. However, this family in ginger (Zingiber officinale Roscoe), a medicinal crop and non-prescription drug, remains unknown to date. In the present study, 66 GRAS genes were identified by searching the complete genome sequence of ginger. The GRAS family is divided into nine subfamilies based on the phylogenetic analyses. The GRAS genes are distributed unevenly across 11 chromosomes. By analyzing the gene structure and motif distribution of GRAS members in ginger, we found that the GRAS genes have more than one cis-acting element. Chromosomal location and duplication analysis indicated that whole-genome duplication, tandem duplication, and segmental duplication may be responsible for the expansion of the GRAS family in ginger. The expression levels of GRAS family genes are different in ginger roots and stems, indicating that these genes may have an impact on ginger development. In addition, the GRAS genes in ginger showed extensive expression patterns under different abiotic stresses, suggesting that they may play important roles in the stress response. Our study provides a comprehensive analysis of GRAS members in ginger for the first time, which will help to better explore the function of GRAS genes in the regulation of tissue development and response to stress in ginger.