[The suppression effect and mechanism of arbuscular mycorrhizal fungi against plant root rot.] / ä¸›æžèŒæ ¹çœŸèŒå¯¹æ¤ç‰©æ ¹è ç— çš„æŠ‘åˆ¶æ•ˆåº”åŠå ¶æœºåˆ¶.

Root rot is a serious soil-borne disease, with negative consequences on crop yield and quality. Arbuscular mycorrhizal (AM) fungi are a group of soil microorganisms, which play important physiological and ecological functions by establishing symbionts with plant roots. AM fungi could induce plant resistance against root rot by regulating physiological and biochemical processes. As a biological agent, AM fungi are used to antagonize soil-borne diseases such as root rot, which is a hotspot in the field of plant-microorganism interaction. We comprehensively reviewed the suppression effect of AM fungi on plant root rot, and the effect of AM fungi on root morphology of host plant, plant nutrition levels, as well as their role in competing with pathogens for ecological sites, activating plant defense systems, and regulating root exudates. Finally, we discussed the potential mechanism of AM fungi inhibiting root rot, as well as the practical problems in the efficient utilization of AM fungi were discussed, in order to provide the theoretical basis for the biological control protocol to antagonize root rot with AM fungi.

Transcriptome Analysis Unravels Metabolic and Molecular Pathways Related to Fruit Sac Granulation in a Late-Ripening Navel Orange (Citrus sinensis Osbeck).

Lanelate navel orange (Citrus sinensis Osbeck) is a late-ripening citrus cultivar increasingly planted in China. The physiological disorder juice sac granulation often occurs in the fruit before harvest, but the physiological and molecular mechanisms underlying this disorder remain elusive. In this study, we found that fruit granulation of the late-ripening navel orange in the Three Gorges area is mainly caused by the low winter temperature in high altitude areas. Besides, dynamic changes of water content in the fruit after freezing were clarified. The granulation of fruit juice sacs resulted in increases in cell wall cellulose and decreases in soluble solid content, and the cells gradually became shrivelled and hollow. Meanwhile, the contents of pectin, cellulose, and lignin in juice sac increased with increasing degrees of fruit granulation. The activities of pectin methylesterase (PME) and the antioxidant enzymes peroxidase (POD), superoxide dismutase, and catalase increased, while those of polygalacturonase (PG) and cellulose (CL) decreased. Furthermore, a total of 903 differentially expressed genes were identified in the granulated fruit as compared with non-disordered fruit using RNA-sequencing, most of which were enriched in nine metabolic pathways, and qRT-PCR results suggested that the juice sac granulation is closely related to cell wall metabolism. In addition, the expression of PME involved in pectin decomposition was up-regulated, while that of PG was down-regulated. Phenylalanine ammonia lyase (PAL), cinnamol dehydrogenase (CAD), and POD related to lignin synthesis were up-regulated, while CL involved in cellulose decomposition was down-regulated. The expression patterns of these genes were in line with those observed in low-temperature treatment as revealed by qRT-PCR, further confirming that low winter temperature is associated with the fruit granulation of late-ripening citrus. Accordingly, low temperature would aggravate the granulation by affecting cell wall metabolism of late-ripening citrus fruit.

[A prospective study of changes in oral health-related quality of life during "all-on-four" immediate restoration for edentulous individuals].

PURPOSE: This clinical study was to evaluate oral health-related quality of life (OHRQoL) changes in patients who underwent all-on-4 treatment in one or both jaws. METHODS: Eleven patients underwent placement of 4 to 6 dental implants on the basis of all-on-4 treatment concept in the maxilla, mandible or both jaws and immediate loading with acrylic interim prostheses. The prostheses were replaced after 3-6 months, and definitive prostheses with metal framework and reinforced resin facing were fixed after another 3 months or more. The subjects completed the shortened Chinese version of the Oral Health Impact Profile (OHIP-14) before surgery (T0), 1 week after interim prostheses were placed (T1) and 3 months after definitive prosthesis placement (T2). The data of 11 subjects were analyzed with Wilcoxon signed-rank test using SPSS 13.0 software package. RESULTS: The total OHIP-14 score significantly reduced only at T2 (P<0.05). "Functional limitation," "physical pain," "physical disability," and "psychological disability" scores significantly decreased at T2, and "psychological discomfort" scores also significantly dropped at T1. "Social disability" and "handicap" scores remained unchanged throughout the treatment course. CONCLUSIONS: Fixed definitive prostheses with metal framework are more effective in improving OHRQoL than fixed acrylic prostheses during all-on-4 treatments.

Indole Alkaloids from the Leaves of Nauclea officinalis.

Three new indole alkaloids, named naucleamide G (1), and nauclealomide B and C (5 and 6), were isolated from the n-BuOH-soluble fraction of an EtOH extract of the leaves of Nauclea officinalis, together with three known alkaloids, paratunamide C (2), paratunamide D (3) and paratunamide A (4). The structures with absolute configurations of the new compounds were identified on the basis of 1D and 2D NMR, HRESIMS, acid hydrolysis and quantum chemical circular dichroism (CD) calculation. According to the structures of isolated indole alkaloids, their plausible biosynthetic pathway was deduced.