[Transcriptome profiling of Saposhnikovia divaricata growing for different years and mining of key genes in active ingredient biosynthesis].

Saposhnikovia divaricata is a commonly used bulk medicinal plant. To explore the key enzyme genes and their expression in the biosynthesis of chromone and coumarin, the key active components, we carried out transcriptome sequencing(Illumina HiSeq) and bioinformatics analysis for the 1-year-old(S1) and 2-year-old(S2) plants of S. divaricata. A total of 40.8 Gb data was obtained. After the sequence assembly via Trinity, 110 732 transcripts and 86 233 unigenes were obtained, which were aligned and annotated with NR, Swiss-Prot, GO, KEGG, and PFAM. Daucus carota and S. divaricata had the highest sequence homology. KEGG pathway enrichment showed that the differentially expressed genes were mainly enriched in plant hormone signal transduction, phenylpropanoid biosynthesis, and flavonoid biosynthesis pathways. A total of 27 differentially expressed unigenes, including 13 enzyme genes, were identified in the pathways related to the synthesis of active ingredients in S. divaricata. Compared with S1 plant, S2 plant showed up-regulated expression of PAL, BGL, C4H, 4CL, CYP98A, CSE, REF, and CCoAOMT and down-regulated expression of CHS, CAD, and COMT. HCT and POD had both up-regulated and down-regulated unigenes. Among them, PAL, C4H, 4CL, BGL, and CHS can be used as candidate genes for the synthesis of the active ingredients in S. divaricata. The four key enzyme genes were verified by RT-qPCR, which showed the results consistent with transcriptome sequencing. This study enriches the genetic information of S. divaricata and provides support for the identification of candidate genes in the biosynthesis of secondary metabolites.

Evaluation of Fusarium Head Blight Resistance in 410 Chinese Wheat Cultivars Selected for Their Climate Conditions and Ecological Niche Using Natural Infection Across Three Distinct Experimental Sites.

Exploiting wheat cultivars with stable resistance to Fusarium Head blight (FHB) and toxin accumulation is a cost-effective and environmentally friendly strategy to reduce the risk of yield losses and contamination with mycotoxins. To facilitate the deployment of stable cultivar resistance, we evaluated FHB resistance and resistance to mycotoxin accumulation in 410 wheat lines bred by local breeders from four major wheat growing regions in China after natural infection at three distinct locations (Hefei, Yangzhou and Nanping). Significant differences in disease index were observed among the three locations. The disease indexes (DI's) in Nanping were the highest, followed by Yangzhou and Hefei. The distribution of DI's in Yangzhou showed the best discrimination of FHB resistance in cultivars. Growing region and cultivar had significant effect on DI and mycotoxins. Among the climate factors, relative humidity and rainfall were the key factors resulting in the severe disease. Even though most cultivars were still susceptible to FHB under the strongly conducive conditions applied, the ratio of resistant lines increased in the Upper region of the Yangtze River (UYR) and the Middle and Lower Region of the Yangtze River (MLYR) between 2015 and 2019. Deoxynivalenol (DON) was the dominant mycotoxin found in Hefei and Yangzhou, while NIV was predominant in Nanping. Disease indexes were significantly correlated with DON content in wheat grain.

[Transcriptome analysis of Platycodon grandiflorum at different growth years and discovery of key genes for platycodin biosynthesis].

Platycodon grandiflorum is a medicinal and edible medicinal material. Our study is aimed to explore the differences in the gene expression of P. grandiflorum in different growth years, and the expression rules of key genes in the biosynthesis of the main active substances of P. grandiflorum. Illumina Hiseq 4000 sequencing platform was used to sequence the transcriptome of P. grandiflorum in different years. Then, 59 654 unigenes were obtained through filtering, assembly, splicing and bioinformatics analysis of the sequencing data, of which 1 671 unigenes were differentially expressed between at least two samples. The results of cluster analysis showed that there was a great difference in the gene expression of P. grandiflorum from one-year-old to two/three-year-old. There were 1 128 different genes between one-and three-year old P. grandiflorum, and only 57 different genes between two-and three-year-old P. grandiflorum. KEGG enrichment results showed that the differential genes of P. grandiflorum in different years were mainly concentra-ted in the biosynthesis of sesquiterpenes and triterpenes, and the biosynthesis of terpenoid skeletons. In the triterpenoid biosynthesis-related pathways, a total of 15 unigenes were identified, involving 5 enzymes. The expression levels of ACAT, HMGR, FDFT1, SQLE decreased with the increase of the growth year of P. grandiflorum. The expression of HMGS was the highest in the one-year-old P. grandiflorum, followed by the three-year-old sample. This study provides useful data for the development of P. grandiflorum, and also provides a basis for the study of related genes in the biosynthetic pathway of platycodin.