Effects of soil drought on cottonseed kernel carbohydrate metabolism and kernel biomass accumulation.

Cottonseed is the main coproduct of cotton production. The carbohydrate metabolism provides carbon substrate for the accumulation of cottonseed kernel biomass which was the basis of cottonseed kernel development. However, the responses of drought stress on carbohydrate metabolism in kernels are still unclear. To address this, two cotton cultivars (Dexiamian 1 and Yuzaomian 9110) were cultivated under three water treatments including soil relative water content (SRWC) at (75 ± 5)% (control), (60 ± 5)% (mild drought) and (45 ± 5)% (severe drought) to investigate the effects of soil drought on cottonseed kernel carbohydrate metabolism and kernel biomass accumulation. Results suggested that drought restrained the accumulation of cottonseed kernel biomass which eventually decreased cottonseed kernel biomass at maturity. In detail, the down-regulation of sucrose phosphate synthase (SPS) activity led to the inhibition of sucrose synthesis, while the up-regulation of invertase (INV) promoted the sucrose decomposite, which reduced the sucrose content eventually under drought. Though hexose content was increased, phosphoenolpyruvic acid (PEP) content was decreased under drought by downregulating 6-phosphofructokinase (PFK) and pyruvate kinase (PK) activities, which hindered the conversion of hexose to PEP. The large decrease of sucrose and PEP contents hindered the accumulation of kernel biomass. The related substances contents and enzyme activities in carbohydrate metabolism of Yuzaomian 9110 were more susceptible to drought stress than Dexiamian 1.

[Biochar addition improves soil phosphorus availability: A meta-analysis]. / ç”Ÿç‰©ç‚­æé«˜åœŸå£¤ç£·ç´ æœ‰æ•ˆæ€§çš„æ•´åˆåˆ†æž.

Biochar is a potential source for improving soil fertility and crop yield by enhancing phosphorus (P) availability. But the information on quantitative effect of biochar addition on soil P availability is still limited. To address this query, we conducted a meta-analysis with 507 data from 95 eligible literature. The results showed that irrespective of biochar characters (raw material, C:N ratio, pyrolysis temperature, application rate), soil characteristics (texture, pH, organic carbon content), and fertilizer application, biochar addition significantly improved soil available P content by 57.6%. Meanwhile, biochar addition promoted P utilization of crops. The response ratios of plant P concentration to biochar addition were generally lower than those of soil available P. The average response ratio of plant P concentration was 30.6%. The biochars, derived from livestock manure, low-temperature pyrolysis, with lower C:N ratio, alkaline, or higher application rate, were more effective to improve soil available P content and plant P concentration in sandy and loamy soils. For main enzymes involved in P cycle, biochar addition increased activity of alkaline phosphatase (2.8%) but decreased the acid phosphatase activity (17.8%). Overall, biochar addition positively affects soil available and plant P concentration, but has a minute effect on soil phosphatase. The improvement of soil P availability might mainly be ascribed to a great amount of active P fractions in biochar itself.

Achyranthes bidentata polypeptides promotes migration of Schwann cells via NOX4/DUOX2-dependent ROS production in rats.

Achyranthes bidentata polypeptides (ABPP), an active polypeptides isolated from the aqueous extract of Achyranthes bidentata Blume, contributes to the regeneration of injured peripheral nerves by promoting migration of Schwann cells (SCs). In this study, we aimed to investigate the possible mechanism underlying the ABPP-induced migration of primary cultured rat SCs. Transwell migration assays indicated that ABPP promoted SCs migration in a concentration-dependent manner by inducing production of NADPH-oxidase (NOX)-derived reactive oxygen species (ROS). Inhibition of ROS production by NOXs inhibitor apocynin (APO) or diphenyleneiodonium (DPI) partially blocked ABPP-mediated SCs migration. Furthermore, by using real-time polymerase chain reaction analysis and siRNA interference technique, we verified the participation of NOX subunit 4 (NOX4) and dual oxidase 2 (DUOX2) in ABPP-induced ROS production and consequential SCs migration. Taken together, these results demonstrated that ABPP promoted SCs migration via NOX4/DUOX2-activated ROS in SCs.