Search

Systemic acquired resistance (SAR) is induced by pathogens and confers protection against a broad range of pathogens. Several SAR signals have been characterized, but the nature of the other unknown signalling by small metabolites in SAR remains unclear. Glutathione (GSH) has long been implicated in the defence reaction against biotic stress. However, the mechanism that GSH increases plant tolerance against virus infection is not entirely known. Here, a combination of a chemical, virus-induced gene-silencing-based genetics approach, and transgenic technology was undertaken to investigate the role of GSH in plant viral resistance in Nicotiana benthamiana. Tobacco mosaic virus (TMV) infection results in increasing the expression of GSH biosynthesis genes NbECS and NbGS, and GSH content. Silencing of NbECS or NbGS accelerated oxidative damage, increased accumulation of reactive oxygen species (ROS), compromised plant resistance to TMV, and suppressed the salicylic acid (SA)-mediated signalling pathway. Application of GSH or l-2-oxothiazolidine-4-carboxylic acid (a GSH activator) alleviated oxidative damage, decreased accumulation of ROS, elevated plant local and systemic resistance, enhanced the SA-mediated signalling pathway, and increased the expression of ROS scavenging-related genes. However, treatment with buthionine sulfoximine (a GSH inhibitor) accelerated oxidative damage, elevated ROS accumulation, compromised plant systemic resistance, suppressed the SA-mediated signalling pathway, and reduced the expression of ROS-regulating genes. Overexpression of NbECS reduced oxidative damage, decreased accumulation of ROS, increased resistance to TMV, activated the SA-mediated signalling pathway, and increased the expression of the ROS scavenging-related genes. We present molecular evidence suggesting GSH is essential for both local and systemic resistance of N. benthamiana to TMV through a differential modulation of SA and ROS., (© 2021 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

Alpha-momorcharin (α-MMC), a member of the plant ribosomal inactivating proteins (RIPs) family, has been proven to exhibit important biological properties in animals, including antiviral, antimicrobial, and antitumour activities. However, the mechanism by which α-MMC increases plant resistance to viral infections remains unclear. To study the effect of α-MMC on plant viral defence and how α-MMC increases plant resistance to viruses, recombinant DNA and transgenic technologies were employed to investigate the role of α-MMC in Nicotiana benthamiana resistance to tobacco mosaic virus (TMV) infection. Treatment with α-MMC produced through DNA recombinant technology or overexpression of α-MMC mediated by transgenic technology alleviated TMV-induced oxidative damage and reduced the accumulation of reactive oxygen species (ROS) during TMV-green fluorescent protein infection of N. benthamiana. There was a significant decrease in TMV replication in the upper leaves following local α-MMC treatment and in α-MMC-overexpressing plants relative to control plants. These results suggest that application or overexpression of α-MMC in N. benthamiana increases resistance to TMV infection. Finally, our results showed that overexpression of α-MMC up-regulated the expression of ROS scavenging-related genes. α-MMC confers resistance to TMV infection by means of modulating ROS homeostasis through controlling the expression of antioxidant enzyme-encoding genes. Overall, our study revealed a new crosstalk mechanism between α-MMC and ROS during resistance to viral infection and provides a framework to understand the molecular mechanisms of α-MMC in plant defence against viral pathogens., (© 2020 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

Introduction: The AP4B1 gene encodes a subunit of adaptor protein complex-4 (AP4), a component of intracellular transportation of proteins which plays important roles in neurons. Bi-allelic mutations in AP4B1 cause autosomal recessive spastic paraplegia-47(SPG47)., Case Presentation: Here we present a Chinese patient with spastic tetraplegia, moderate psychomotor development delay and febrile seizures plus. Brain MRIs showed dilated supratentorial ventricle, thin posterior and splenium part of corpus callosum. The patient had little progress through medical treatments and rehabilitating regimens. Whole exome sequencing identified novel compound heterozygous truncating variants c.1207C > T (p.Gln403*) and c.52_53delAC (p.Cys18Glnfs*7) in AP4B1 gene. Causal mutations in AP4B1 have been reported in 29 individuals from 22 families so far, most of which are homozygous mutations., Conclusions: Our study enriched the genetic and phenotypic spectrum of SPG47. Early discovery, diagnosis and proper treatment on the conditions generally increase chances of improvement on the quality of life for patients.

Objective: To explore the therapeutic effect of acupuncture for spastic cerebral palsy in infancy stage., Methods: A total of 62 children with spastic cerebral palsy were randomized into an observation group and a control group, 31 cases in each one. Both groups were given comprehensive rehabilitation therapy (sport therapy, electronic biofeedback therapy, speech cognitive training, massage therapy). On the basis of comprehensive rehabilitation therapy, the acupuncture group was treated with acupuncture at Baihui (GV 20), Sishencong (EX-HN1), motor area, Jiaji (EX-B 2), Weizhong (BL 40), Xuanzhong (GB 39), Zusanli (ST 36) and Hegu (LI 4), etc, the needles were retained for 15-20 min each time, once a day, 5 days a week, 45 days as a course with 10 days interval, a total of 3 courses were required. The Gesell development scale adaptive DQ scores, gross motor function measure (GMFM88) and muscular tension of adductor and gastrocnemius muscle were compared before and after treatment in the two groups., Results: The Gesell development scale adaptive DQ score after treatment in the observation group was increased ( P <0.05), there was no significant difference before and after treatment in the control group ( P >0.05), the change of the observation group was larger than the control group ( P <0.05). After treatment, the GMFM88 scores in the two groups were significantly increased ( P <0.05), the change of the observation group was larger than the control group ( P <0.05). After treatment, the muscular tension of the adductor in the two groups were decreased ( P <0.05), the change of the observation group was larger than the control group ( P <0.05). After treatment, the muscle tension of the gastrocnemius muscle in the two groups were decreased ( P <0.05), there was no significant difference between the two groups in the variation range ( P >0.05)., Conclusion: Acupuncture combined with comprehensive rehabilitation therapy can improve cognitive function, spasticity and motor function of children with spastic cerebral palsy.

Background: Pre-treated patients with first-line treatment can be offered a second treatment with the aim of improving their poor clinical prognosis. The therapy of metastatic colorectal cancer (CRC) patients who did not respond to first-line therapy has limited treatment options. Recently, many studies have paid much attention to the efficacy of bevacizumab as an adjuvant treatment for metastatic colorectal cancer., Objectives: We aimed to evaluate the efficacy and toxicity of bevacizumab plus chemotherapy compared with bevacizumab-naive based chemotherapy as second-line treatment in people with metastatic CRC., Methods: Electronic databases were searched for eligible studies updated to March 2018. Randomized-controlled trials comparing addition of bevacizumab to chemotherapy without bevacizumab in MCRC patients were included, of which, the main interesting results were the efficacy and safety profiles of the addition of bevacizumab in patients with MCRC as second-line therapy., Result: Five trials were eligible in the meta-analysis. Patients who received the combined bevacizumab and chemotherapy treatment in MCRC as second-line therapy showed a longer overall survival (OS) (OR=0.80,95%CI=0.72-0.89, P<0.0001) and progression-free survival (PFS) (OR=0.69,95%CI=0.61-0.77, P<0.00001). In addition, there was no significant difference in objective response rate (ORR) (RR=1.36,95%CI=0.82-2.24, P=0.23) or severe adverse event (SAE) (RR=1.02,95%CI=0.88-1.19, P=0.78) between bevacizumab-based chemotherapy and bevacizumabnaive based chemotherapy., Conclusion: Our results suggest that the addition of bevacizumab to the chemotherapy therapy could be an efficient and safe treatment option for patients with metastatic colorectal cancer as second-line therapy and without increasing the risk of an adverse event., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Aimed to understand the translocation and transformation characteristics of applied fertilizer nitrogen in paddy soil, a simulated soil column experiment was conducted in laboratory to study the variations of soil mineral nitrogen along the profile under the application of 360 mg x kg(-1) (3 folds of conventional application rate) of urea- and ammonium sulfate nitrogen. In the experimental period, the soil NH4(+)-N and NO3(-)-N contents in the control (no fertilization) had less change, and no significant differences among different soil layers. Applying urea- and ammonium sulfate nitrogen resulted in a significant increase of soil NH4(+)-N and NO3(-)-N in 0-50 mm layer, being 186.0-2882.1 mg x kg(-1) and 268.7-351.5 mg x kg(-1), and 4.8-242 times and 5.7-316 times of those in CK, respectively. However, the NH4(+)-N and NO3(-)-N contents below 50 mm soil depth were similar to those in CK, indicating that the translocation and transformation of applied fertilizer nitrogen mainly occurred in 0-50 mm soil layer. The translocation of fertilizer nitrogen mostly occurred in the first 14 days after fertilization. In the whole experimental period, the NH4(+)-N and NO3(-)-N contents in each soil layer under the application of ammonium sulfate were 0.7-2.0 times of those under the application of urea, and the nitrification rate was 0.9-1.4 times of that, suggesting the higher transformation rate of applied ammonium sulfate in paddy soil, as compared with applied urea.

A laboratory incubation test was conducted to study the organic C mineralization in gray forest soils after land use conversion and the temperature sensitivity of the mineralization. It was shown that after the conversion from wildwood land to farmland, the organic C and total N contents in 0-10 cm and 10-20 cm soil layers decreased by 68.5% and 76.8%, and 40.5% and 44.4%, and the average mineralization rate and cumulative mineralization of soil organic C in farmland were 24.4%-43.2% and 9.20%-13.7% of those in wildwood land, respectively. At lower temperature (< 25 degrees C), there was no significant difference in the temperature sensitivity of soil organic C mineralization between the two land use types; while at higher temperature ( > 25 degrees C), this temperature sensitivity in farmland soil was higher in 0-10 cm layer but significantly lower in 10-20 cm layer, compared with that in wildwood land soil.

Iron oxide is abundant in red soil. Reduction and oxidation of iron oxide are important biogeochemical processes. In this paper, we reported the effects of humic acid on dissimilatory iron reduction (DISSIR) in red soil by adding glucose or humic acid (HA), under an anaerobic condition. Results indicated that DISSIR is weak for the red soil with a low content of organic matter, Glucose that act as electron donators promoted the process of DISSIR in red soil. HA added to soil solely didn't accelerate the DISSIR since it couldn't provide electron donators to microbe. However, adding of both glucose and HA promoted the DISSIR at the beginning of the incubation but then inhibited the process, which maybe caused by the effects of precipitation and adsorption of red soil. Concentrations of HA strongly affected the DISSIR, HA at low concentrations(0.20 and 0.02 g/kg) had weak effects, while HA at a high concentration (2.00 g/kg) promoted the process at the beginning and then inhibited it. HA extracted from different materials had distinct effects on the DISSIR. HA from Weathering coal of Datong in Shanxi Province (HAs), lignite of Gongxian in Henan Province (HAh) and Dianchi Lake sediment in Kunming of Yunnan Province (HAk) all promoted the DISSIR at the beginning of the incubation. However, at the end of incubation, HAk with a low aromaticity still promoted the process, while HAs and HAh with a higher aromaticity weakened the DISSIR. This may be due to the increase in adsorption of soil with the aromaticity of HA.

With incubation tests in laboratory, the mineralization of organic carbon in various size aggregates of paddy soil was investigated under aerobic and submerged conditions. The results showed that the organic carbon mineralization in various size aggregates decreased quickly at the beginning of the incubation, but remained stable during the late period of incubation. The mineralization rate varied significantly with the size of the aggregates. Through the incubation time, the organic carbon in 1-2 mm aggregates had the highest mineralization rate, while that in < 0.053 mm aggregates had the lowest one. Statistic analyses indicated that the mineralization rate of organic carbon in various size aggregates was significantly and linearly correlated with the contents of organic carbon and microbial biomass carbon in the aggregates. 0.25-1 mm aggregates had the highest contribution to the cumulative mineralization of soil organic carbon, accounting for 41.77% under aerobic condition and 34.11% under submerged condition, while < 0.053 mm and 1-2 mm aggregates had the lowest contribution under aerobic and submerged conditions, accounting for 7.8% and 6.6%, respectively.