• WEI WANG

Articles written in Journal of Biosciences

• Contribution of root to soil respiration and carbon balance in disturbed and undisturbed grassland communities, northeast China

Changes in the composition of plant species induced by grassland degradation may alter soil respiration rates and decrease carbon sequestration; however, few studies in this area have been conducted. We used net primary productivity (NPP), microbial biomass carbon (MBC), and soil organic carbon (SOC) to examine the changes in soil respiration and carbon balance in two Chinese temperate grassland communities dominated by Leymus chinensis (undisturbed community; Community 1) and Puccinellia tenuiflora (degraded community; Community 2), respectively. Soil respiration varied from 2.5 to 11.9 g CO2 m-2 d-1 and from 1.5 to 9.3 g CO2 m-2 d-1, and the contribution of root respiration to total soil respiration from 38% to 76% and from 25% to 72% in Communities 1 and 2, respectively. During the growing season (May–September), soil respiration, shoot biomass, live root biomass, MBC and SOC in Community 2 decreased by 28%, 39%, 45%, 55% and 29%, respectively, compared to those in Community 1. The considerably lower net ecosystem productivity in Community 2 than in Community 1 (104.56 vs. 224.73 g C m-2 yr-1) suggests that the degradation has significantly decreased carbon sequestration of the ecosystems.

• Vitamin D regulates cell viability, migration and proliferation by suppressing galectin-3 (Gal-3) gene in ovarian cancer cells

Vitamin D deficiency is identified as a risk factor for the occurrence and recurrence of ovarian cancer.Galectin-3 (Gal-3) participates in many physiological and pathological processes. In present study, serumvitamin D level was detected using chemiluminescence enzyme immunoassay. Gal-3 expression wasexamined using real-time polymerase chain reaction (PCR), Western blot and immunocytochemistry analysis.SKOV3 cells viability was assessed by the water-soluble tetrazolium salt (WST-1) assay, the migrationof SKOV3 cells was detected using transwell assay, and the proliferation of SKOV3 cells was measured by3H-thymidine incorporation (3H-TdR). Our study demonstrated that vitamin D levels were lower in 40ovarian cancer patients: vitamin D deficiency is closely related to the pathogenesis of ovarian cancer.Treatment with vitamin D reduced the migration and proliferation of ovarian cancer cells. Gal-3 wasoverexpressed in ovarian cancer, which could induce the viability, migration and proliferation ability ofovarian cancer cells, and these effects were abrogated by vitamin D downregulating the expression of Gal-3gene. Therefore, our results support that vitamin D may suppress Gal-3-induced viability, migration andproliferation ability of ovarian cancer cells, which suggests that the use of vitamin D may have beneficialeffects in preventing and treating ovarian cancer.

• Choline-betaine pathway contributes to hyperosmotic stress and subsequent lethal stress resistance in Pseudomonas protegens SN15-2

Pseudomonas protegens SN15-2, a typical non-spore-forming rhizosphere bacterium, has excellent biocontrolcapabilities; thus, it is necessary to explore the stress resistance of SN15-2. The choline–glycine betainepathway is considered as an important mechanism by which bacteria adapt to stressful environments. In thiswork, we demonstrated that the expression of the betA and betB genes, which are involved in the choline–glycine betaine pathway in SN15-2, was highly increased by 12-fold and 26-fold, respectively, by hyperosmoticstress and choline treatment. The accumulation of betaine in SN15-2 (5.54 g/L) was significantly higherthan that in the mutants $\Delta$ betA (3.44 g/L) and $\Delta$ betB (2.68 g/L) under hyperosmotic stress and cholinetreatment. Moreover, choline enhanced the growth of SN15-2 greatly, but it did not enhance the growth of $\Delta$betB under hyperosmotic stress. Choline combined with hyperosmotic adaptation significantly increased thelethal stress resistance of SN15-2 while the resistance of $\Delta$ betA and $\Delta$ betB was significantly decreased. Thisresearch illuminated a strategy underlying the adaptation to osmotic stress in P. protegens and provided aneffective method to improve the stress resistance of this species, thus provided a theoretical basis for thepractical application of P. protegens SN15-2.

• # Journal of Biosciences

Volume 46, 2020
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Posted on July 25, 2019

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