RESUMO
Persimmon leaves are used for making persimmon leaf tea or as functional ingredients due to their enrichment in flavonoids, the beneficial mineral contents, and favorable flavors contributed by volatile aroma compounds. The varieties/cultivars had a significant influence on the quality and flavor of persimmon leaf tea. In this study, the integrated metabolomic-transcriptomic analysis was conducted to investigate the potential in flavonoid biosynthesis, mineral absorption, and degradation of aromatic compounds from tender leaves of "Diospyros kaki. Heishi" (HS), "Diospyros kaki Thunb. Nishimurawase" (NM), and "Diospyros kaki Thunb. Taifu" (TF), using rootstock "Diospyros Lotus Linn" (DL) as the control. The metabolomic analysis showed that 382, 391, and 368 metabolites were differentially accumulated in the comparison of DL vs. HS, DL vs. NM, and DL vs. TF, respectively, and 229 common metabolites were obtained by comparative analysis. By RNA sequencing, 182,008 unigenes with 652 bp of mean length were annotated and 2,598, 3,503, and 3,333 differentially expressed genes (DEGs) were detected from the comparison of DL vs. HS, DL vs. NM, and DL vs. TF, respectively. After the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, 6, 6, and 3 DEGs [with | log2(fold change)| ≥ 1 simultaneously in the three comparisons] involved in flavonoid biosynthesis, mineral absorption, and degradation of aromatic compounds, respectively, were selected for quantitative reverse transcription-polymerase chain reaction (qRT-PCR) validation and the consistent trends of the relative expression level of each DEG with RNA sequencing (RNA-seq) data were observed. Based on the transcriptomic analysis and qRT-PCR validation, it was observed that the leaves of HS, NM, and TF had the greatest level of mineral absorption, flavonoid biosynthesis, and degradation of aromatic compounds, respectively. In addition, a positive correlation between the 15 DEGs and their metabolites was observed by the conjoint analysis. Thus, the tender leaves of HS, NM, and TF could be recommended for the production of persimmon leaf tea rich in mineral elements, flavonoid, and aroma compounds, respectively.
RESUMO
The genetic diversity of 279 indivdiuals from 10 populations in Shandong Province was investigated using inter-simple sequence repeat (ISSR) markers. As a result, 116 bands were amplified by 10 informative and reliable primers, of which 101 were polymorphic loci. A relatively high level of genetic diversity was revealed: PPL = 87.07, He = 0.2697, H0 = 0.3999 (at the species level); PPL = 64.58, He = 0.2004, H0 = 0.3010 (at the population level). A higher level of genetic differentiation was detected among populations with Nei's G(ST) analysis and the analysis of molecular variance (AMOVA; G(ST) = 0.2414, F(ST) = 0.2224). Habitat fragmentation and gene flow may result in genetic differentiation. UPGMA cluster analysis indicated that the four populations from Linshu, Junan, Tancheng and Feixian grouped together, whereas Laiyang populations clustered in an isolated clade. The results showed that a mixed mating system was possibly the main factor influencing the genetic structure of this species. These results, combined with other information about Castanea mollissima, may provide a valuable basis for proposing conservation strategies.
