No abstract

BACKGROUND: Frequent fungal diseases tend to lead to severe losses in rice production. As a main component of the fungal cell wall, glucan plays an important role in the growth and development of fungi. Glucanase can inhibit the growth of fungi by breaking glycosidic bonds, and may be a promising target for developing rice varieties with broad-spectrum disease resistance.RESULTS: We transferred a codon-optimized ⊎-1,6-glucanase gene (GluM) from myxobacteria into the japonica rice variety Zhonghua11 (ZH11), and obtained a large number of individual transgenic plants with GluM overexpression. Based on molecular analysis, three single-copy homozygous lines with GluM overexpression were selected for assessment of fungal disease resistance at the T 3 generation. Compared with that of the recipient cultivar ZH11, the area of rice blast lesion in transgenic rice was reduced by 82.71%; that of sheath blight lesion was decreased by 35.76%-43.67%; the sheath blight resistance in the field was enhanced by an average of 0.75 grade over 3 years; and the incidence of diseased panicles due to rice false smut was decreased by 65.79%. More importantly, there was no obvious loss of yield (without a significant effect on agronomic traits). Furthermore, plants overexpressing a ⊎-1,6-glucanase gene showed higher disease resistance than rice plants overexpressing a ⊎-1,3-glucanase gene derived from tobacco.CONCLUSION: The ⊎-1,6-glucanase gene GluM can confer broad-spectrum disease resistance to rice, providing an environmentally friendly alternative way to effectively manage fungal pathogens in rice production.

Enterovirus 71 (EV71) is the predominant pathogen for severe hand, foot, and mouth disease (HFMD) in children younger than 5 years, and currently no effective drugs are available for EV71. Thus, there is an urgent need to develop new drugs for the control of EV71 infection. In this study, LJ04 was extracted from Laminaria japonica using diethylaminoethyl cellulose‐52 with 0.4 mol/l NaCl as the eluent, and its virucidal activity was evaluated based on its cytopathic effects on a microplate. LJ04 is composed of fucose, galactose, and mannose and mainly showed good virucidal activity against EV71. The antiviral mechanisms of LJ04 were the direct inactivation of the virus, the blockage of virus binding, disruptions to viral entry, and weak inhibitory activity against the nonstructural protein 3C. The two most important findings from this study were that LJ04 inhibited EV71 proliferation in HM1900 cells, which are a human microglia cell line, and that LJ04 can directly inactivate EV71 within 2 hr at 37°C. This study demonstrates for the first time the ability of a polysaccharide from L. japonica to inhibit viral and 3C activity; importantly, the inhibition of 3C might have a minor effect on the antiviral effect of LJ04. Consequently, our results identify LJ04 as a potential drug candidate for the control of severe EV71 infection in clinical settings.

Gastric cancer is a malignant tumor that is originated from the epithelia of the gastric mucosa. Although the gastroscopic biopsy of suspicious gastric areas can provide better early-warning opportunities for patients with malignant tumors that result in achieving early diagnosis and treatment, many malignant tumors are still excluded due to atypical histology, sampling errors, nonspecific antibodies, and other reasons, which pose a threat to the physical and mental health of patients. Therefore, more sensitive and specific detection methods of gastric cancer are needed to improve the screening efficiency of gastroscopic biopsy. The sensitivity of nano PCR was 10 times higher than that of conventional PCR. In comparison with the conventional RT-PCR method, nano PCR technology can amplify brighter bands and identify higher gene expression levels for ALK weak positive gastric cancer in IHC, and improve the detection rate of clinical specimens with lower ALK staining. Therefore, nano-gold polymerase chain reaction used gold nanoparticle (nano-gold PCR) has high sensitivity and positive detection rate for ALK-positive gastric cancer identified by gastroscopy. When a low concentration was observed for the amplified gene, especially when the biopsy tissue was too small to carry out IHC staining, the target gene could be amplified more effectively. Therefore, nano PCR technology is proposed to be widely used in target gene detection of biopsy tissue to achieve better tumor screening.