[Identification of Carthamus tinctorius NAC gene family and analysis of drought stress response].

The NAC(NAM/ATAF/CUC) transcription factors are members of the largest transcriptional gene family in plants and play an essential role in the response of plants to drought stress. To identify the number and function of the NAC gene family in Carthamus tinctorius, the present study adopted bioinformatics methods to identify NAC gene family members based on the whole genome data of C. tinctorius, and analyzed their physicochemical properties, chromosomal location, phylogenetic relationship, gene structure, conserved domain, and conserved motif. Meanwhile, the real-time fluorescence-based quantitative RT-PCR(qRT-PCR) was used to analyze the transcription level of four NAC genes under drought stress in different time. The results showed that C. tinctorius contained 87 NAC genes unevenly distributed on 11 chromosomes, while no NAC gene was found on chromosome 12. The encoded proteins were 103-974 amino acids and the number of CDS ranged from 3 to 9. According to the phylogenetic relationships, 87 NAC genes were clustered into17 subfamilies. The analysis of conserved domains and motifs revealed that most of the genes contained five conserved subdomains, A-E and motif2 was the most conserved among NAC genes. The expression pattern analysis showed that the transcription levels of four NAC genes related to drought resistance were all up-regulated after drought stress treatment for different time, suggesting that these four NAC genes may be related to drought resistance of C. tinctorius. This study is expected to provide a theoretical basis for further functional analysis of NAC transcription factors in C. tinctorius and references for the cultivation of drought-tolerant C. tinctorius varieties.

Complete chloroplast genome sequence of Chrysosplenium nudicaule (Saxifragaceae).

Chrysosplenium nudicaule Bunge, Tibetan name 'Yajima,' growing in the highlands of China is a perennial herb belonging to the genus Chrysosplenium Saxifragaceae. As a traditional Chinese medicine, it has been used to treat digestive diseases for hundreds of years. The complete chloroplast genome of Chrysosplenium nudicaule is 152,775 bp in length and comprises two inverted repeats (IR, 25,962 bp), a large single-copy region (LSC, 83,533 bp), and a small single-copy region (SSC, 17,318 bp). It harbors 112 genes, including 78 protein-coding genes, four ribosomal RNA genes, and 30 transfer RNA genes. In addition, the rpl32 gene was deleted. The GC content of the whole chloroplast genome is 37.54%. This chloroplast genome resource will be useful for study on the evolution and genetic diversity of C. nudicaule in the future.