Rhizospheric soil fungal community patterns of Duchesnea indica in response to altitude gradient in Yunnan, southwest China.

The magnitude of the impact of altitude gradient on microbial community and diversity has been studied in recent decades. Whereas bacteria have been the focus of most studies, fungi have been given relatively less attention. As a vital part of the macro- and microscopic ecosystem, rhizosphere fungi play a key role in organic matter decomposition and relative abundance of plant species and have an impact on plant growth and development. Using Duchesnea indica as the host plant, we examined the rhizosphere soil fungal community patterns across the altitude gradient in 15 sites of Yunnan province by sequencing the fungal ITS2 region with the Illumina MiSeq platform. We determined the fungal community composition and structure. We found that, surprisingly, rhizosphere soil fungal diversity of D. indica increased with altitudinal gradient. There was a slight difference in diversity between samples from high- and medium-altitude sites, with medium-altitude sites having the greater diversity. Furthermore, the rhizosphere soil fungal community composition and structure kept changing along the altitudinal gradient. Taxonomic results showed that the extent of phylum diversity was greatest at high-altitude sites, with Ascomycota, Basidiomycota, Zygomycota, and Glomeromycota as the most dominant fungal phyla.

Comparative transcriptome analyses between a spontaneous late-ripening sweet orange mutant and its wild type suggest the functions of ABA, sucrose and JA during citrus fruit ripening.

A spontaneous late-ripening mutant of 'Jincheng' (C. sinensis L. Osbeck) sweet orange exhibited a delay of fruit pigmentation and harvesting. In this work, we studied the processes of orange fruit ripening through the comparative analysis between the Jincheng mutant and its wild type. This study revealed that the fruit quality began to differ on 166th days after anthesis. At this stage, fruits were subjected to transcriptome analysis by RNA sequencing. 13,412 differentially expressed unigenes (DEGs) were found. Of these unigenes, 75.8% were down-regulated in the wild type, suggesting that the transcription level of wild type was lower than that of the mutant during this stage. These DEGs were mainly clustered into five pathways: metabolic pathways, plant-pathogen interaction, spliceosome, biosynthesis of plant hormones and biosynthesis of phenylpropanoids. Therefore, the expression profiles of the genes that are involved in abscisic acid, sucrose, and jasmonic acid metabolism and signal transduction pathways were analyzed during the six fruit ripening stages. The results revealed the regulation mechanism of sweet orange fruit ripening metabolism in the following four aspects: First, the more mature orange fruits were, the lower the transcription levels were. Second, the expression level of PME boosted with the maturity of the citrus fruit. Therefore, the expression level of PME might represent the degree of the orange fruit ripeness. Third, the interaction of PP2C, PYR/PYL, and SnRK2 was peculiar to the orange fruit ripening process. Fourth, abscisic acid, sucrose, and jasmonic acid all took part in orange fruit ripening process and might interact with each other. These findings provide an insight into the intricate process of sweet orange fruit ripening.

High expression of osteoglycin decreases gelatinase activity of murine hepatocarcinoma Hca-F cells.

AIM: To investigate the possible correlation between osteoglycin expression and gelatinase activity of mouse hepatocarcinoma Hca-F cells. METHODS: A eukaryotic expression plasmid pIRESpuro3 osteoglycin(+) was constructed and transfected into Hca-F cells to investigate the possible correlation between osteoglycin expression and gelatinase activity of Hca-F cells cultured with extract of lymph node, liver, spleen or in DMEM medium. The activity of gelatinases was examined through zymographic analysis. RESULTS: High expression of osteoglycin attenuated the gelatinase activity of Hca-F cells cultured with extract of lymph node, and at the same time, decreased the metastatic potential of Hca-F cells to peripheral lymph nodes in vivo. CONCLUSION: High expression of osteoglycin decreases the gelatinase activity of Hca-F cells cultured with extract of lymph node; regulation of gelatinase activity might be one of mechanisms that osteoglycin contributes to lymphatic metastasis suppression.