Genetic variability of rice stripe virus after its pandemic in Jiangsu.

BACKGROUND: Rice stripe virus (RSV) caused a serious disease pandemic in rice in East China between 2001 and 2010. The continuous integrated managements reduced virus epidemic year by year until it was non-epidemic. As an RNA virus, its genetic variability after undergoing a long-term non-epidemic period was meaningful to study. While in 2019, the sudden occurrence of RSV in Jiangsu provided an opportunity for the study. METHODS AND RESULTS: The complete genome of JY2019, an RSV isolate from Jiangyan, was determined. A genotype profile of 22 isolates from China, Japan and Korea indicated that the isolates from Yunnan formed the subtype II, and other isolates clustered the subtype I. RNA 1-3 of JY2019 isolate well-clustered in the subtype I clade, and RNA 4 was also in subtype I, but it had a slight separation from other intra-group isolates. After phylogenetic analyses, it was considered NSvc4 gene contributed to the tendency, because it exhibited an obvious trend towards the subtype II (Yunnan) group. High sequence identity (100%) of NSvc4 between JY2019 and barnyardgrass isolate from different regions demonstrated genetic variation of NSvc4 was consistent in RSV natural populations in Jiangsu in the non-epidemic period. In the phylogenetic tree of all 74 NSvc4 genes, JY2019 belonged to a minor subtype Ib, suggesting the subtype Ib isolates might have existed in natural populations before the non-epidemic period, but not a dominant population. CONCLUSIONS: Our results suggested that NSvc4 gene was susceptible to selection pressure, and the subtype Ib might be more adaptable for the interaction between RSV and hosts in the non-epidemic ecological conditions.

Effect of flavonoids from Hippophae rhamniodes residues on blood lipoid metabolism and antioxidative activity in climacteric rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of flavonoids from seed residues of Hippophae rhamnoides (FH) on the lipid metabolism and antioxidative activity in climacteric rats.</p><p><b>METHOD</b>Menopausal rats with aging were used in this experiment. The rats were fed with FH by gastrogavage for 13 weeks. The effect of drug on the lipid metabolism and the antioxidative activity were observed after the rats were killed.</p><p><b>RESULT</b>Serum total cholesterol was decreased significantly in rats fed with FH, T-AOC and SOD in serum and liver were significantly higher than those in rats fed with water, and at the same time MDA was lower than that in rats fed with water.</p><p><b>CONCLUSION</b>FH can improve the climacteric rats' lipid metabolism, and enhance the antioxidation in climacteric rats.</p>