De novo transcriptome sequencing of Impatiens uliginosa and the analysis of candidate genes related to spur development.

BACKGROUND: Spur, a structure capable of producing and storing nectar, not only plays a vital role in the pollination process but also promotes the rapid diversification of some plant lineages, which is considered a key innovation in plants. Spur is the focus of many studies, such as evolution and ecological hypothesis, but the current understanding of spur development is limited. High-throughput sequencing of Impatiens uliginosa was carried out to study the molecular mechanism of its spur development, which is believed to provide some insights into the spur development of Impatiens. RESULTS: Transcriptomic sequencing and analysis were performed on spurs and limbs of I. uliginosa at three developmental stages. A total of 47.83 Gb of clean data were obtained, and 49,716 unigene genes were assembled. After comparison with NR, Swiss-Prot, Pfam, COG, GO and KEGG databases, a total of 27,686 genes were annotated successfully. Through comparative analysis, 19,356 differentially expressed genes were found and enriched into 208 GO terms and 146 KEGG pathways, among which plant hormone signal transduction was the most significantly enriched pathway. One thousand thirty-two transcription factors were identified, which belonged to 33 TF families such as MYB, bHLH and TCP. Twenty candidate genes that may be involved in spur development were screened and verified by qPCR, such as SBP, IAA and ABP. CONCLUSIONS: Transcriptome data of different developmental stages of spurs were obtained, and a series of candidate genes related to spur development were identified. The importance of genes related to cell cycle, cell division, cell elongation and hormones in spur development was clarified. This study provided valuable information and resources for understanding the molecular mechanism of spur development in Impatiens.

The complete chloroplast genome sequence of sugar beet (Beta vulgaris ssp. vulgaris).

The complete nucleotide sequence of the sugar beet (Beta vulgaris ssp. vulgaris) chloroplast genome (cpDNA) was determined in this study. The cpDNA was 149,637 bp in length, containing a pair of 24,439 bp inverted repeat regions (IR), which were separated by small and large single copy regions (SSC and LSC) of 17,701 and 83,057 bp, respectively. 53.4% of the sugar beet cpDNA consisted of gene coding regions (protein coding and RNA genes). The gene content and relative positions of 113 individual genes (79 protein encoding genes, 30 tRNA genes, 4 rRNA genes) were almost identical to those of tobacco cpDNA. The overall AT contents of the sugar beet cpDNA were 63.6% and in the LSC, SSC and IR regions were 65.9%, 70.8% and 57.8%, respectively. Fifteen genes contained one intron, while three genes had two introns.