Response of rice (Oryza sativa L.) roots to nanoplastic treatment at seedling stage.

Potential adverse effects of nanoplastics (NPs) on marine organisms have received increased attention in recent years. In contrast, few data are available on terrestrial plants, especially on the mechanisms for transport of NPs in plants and phytotoxicity (at both phenotypic and molecular levels) of plants induced by NPs. To address this knowledge gap, we conducted a microcosm study in which hydroponically-cultured rice (Oryza sativa L.) seedlings were exposed to polystyrene (PS)-NPs at 0, 10, 50, and 100 mg L-1 for 16 d and examined for morphological and physiological phenotypes and transcriptomics. Laser confocal scanning micrographs confirmed PS-NPs were uptaken by rice roots, greatly benefitted from the transport activity of aquaporin in rice roots. The significant enhancement (p < 0.05) of antioxidant enzyme activities reflected the oxidative stress response of rice roots upon exposure to PS-NPs. Treatment by PS-NPs decreased root length and increased lateral root numbers. Carbon metabolism was activated (e.g., increased carbon and soluble sugar contents) whereas jasmonic acid and lignin biosynthesis were inhibited. The present study demonstrated the likelihood for transport of PS-NPs in rice roots and induced phytotoxicity by PS-NPs, which should inspire further investigations into the potential human health risks from rice consumption.

[The role of transforming growth factor beta1 R II and interleukin 13 Ralpha2 in schistosomiasis-induced hepatic fibrosis].

Schistosomiasis hepatic fibrosis results from excessive deposition of extracellular matrix components which are produced from the activated hepatic stellate cells in liver. Cytokine network disorder is the essential cause of the development of schistosomiasis liver fibrosis. Transforming growth factor beta1 (TGF-beta1) and interleukin 13 (IL-13) promote fibrosis through hepatic stellate cell membrane-specific receptor. This paper reviews the effects of TGF-beta1 type II (TGF-beta1 R II) receptor and IL-13 receptor alpha2 (IL-13 Ralpha2) on hepatic fibrosis.

Biotransformation of ginsenoside Rb1 to ginsenoside Rd by highly substrate-tolerant Paecilomyces bainier 229-7.

Paecilomyces bainier 229-7 was obtained after UV irradiation for 8 min in the presence of 0.4% LiCl and selection on potato dextrose media containing 30 mg/mL saponin from Panax notoginseng leaves (SPNL). The mutant produces ginsenoside Rd from ginsenoside Rb1 with a bioconversion rate as high as 94.9% under optimized culture conditions in shake flasks when supplied with 20 mg/mL of SPNL. Scale-up in 10-L fermenter resulted in an 89% bioconversion rate. Ginsenoside Rd was purified from the culture medium by a macroporous resin with a chromatographic purity of 92.6%. These results suggest that P. bainier 229-7 could be useful for the preparation of ginsenoside Rd in the pharmaceutical industry.