White and green striate leaves 1, predicted to encode a 16S rRNA processing protein, plays a critical role in the processing of chloroplast ribosomes in maize (Zea mays L.).

Ribosomes play a crucial role in protein biosynthesis and are linked to plant growth and development. The RimM protein has been shown to be involved in the maturation of 30S ribosomal subunits, but its exact function in plants is still unknown. In this study, we discovered a maize mutant with white and green striate leaves (wgsl1) and reduced chlorophyll content. Genetic analysis showed that the wgsl1 mutation was recessive and controlled by a single nuclear gene. Map-based cloning of ZmWGSL1 identified a base substitution (G to A) that generated a missense mutation within the Zm00001d039036 gene in the wgsl1 mutant. Zm00001d039036 encodes a 16S rRNA processing protein containing the RimM motif. Further analysis of transcriptomic data showed that the transcript levels of many ribosomal proteins involved in the small and big ribosomal subunits were dramatically up-regulated in the wgsl1 mutant. Moreover, the level of ribosomal multimers was decreased. This suggests that ZmWGSL1 plays a crucial role in the maturation of the ribosome, leading to abnormal plant growth and development. In addition, subcellular localization results indicate that WGSL1 is localized in chloroplasts. Therefore, we suggest that WGSL1 is a nuclear-encoded protein, is transported to the chloroplast to drive functions, and affects the processing of ribosomes in the chloroplast. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01407-y.

Genome assembly of the Chinese maize elite inbred line RP125 and its EMS mutant collection provide new resources for maize genetics research and crop improvement.

Maize is an important crop worldwide, as well as a valuable model with vast genetic diversity. Accurate genome and annotation information for a wide range of inbred lines would provide valuable resources for crop improvement and pan-genome characterization. In this study, we generated a high-quality de novo genome assembly (contig N50 of 15.43 Mb) of the Chinese elite inbred line RP125 using Nanopore long-read sequencing and Hi-C scaffolding, which yield highly contiguous, chromosome-length scaffolds. Global comparison of the RP125 genome with those of B73, W22, and Mo17 revealed a large number of structural variations. To create new germplasm for maize research and crop improvement, we carried out an EMS mutagenesis screen on RP125. In total, we obtained 5818 independent M2 families, with 946 mutants showing heritable phenotypes. Taking advantage of the high-quality RP125 genome, we successfully cloned 10 mutants from the EMS library, including the novel kernel mutant qk1 (quekou: "missing a small part" in Chinese), which exhibited partial loss of endosperm and a starch accumulation defect. QK1 encodes a predicted metal tolerance protein, which is specifically required for Fe transport. Increased accumulation of Fe and reactive oxygen species as well as ferroptosis-like cell death were detected in qk1 endosperm. Our study provides the community with a high-quality genome sequence and a large collection of mutant germplasm.

Detection of Pseudomonas aeruginosa in the Skin by Immunomagnetic Isolation and Real-Time Quantitative PCR.

Pseudomonas aeruginosa (P. aeruginosa) causes a broad spectrum of skin infections and early treatment with antibiotics is critical for successful therapy. Currently, P. aeruginosa is detected by time-consuming culturing and counting the bacteria. Therefore, the goal of the present study was to design a rapid, sensitive, and specific protocol for the identification of P. aeruginosa infection in the skin. For this purpose, a methodology was developed which combines isolation of bacteria by species-specific immunomagnetic beads, extraction of DNA by magnetic particles, and confirmation of the identity of P. aeruginosa by real-time PCR. The efficiency of P. aeruginosa extraction from skin samples was greater than 90%, while only minimal amounts of other species were captured by immunomagnetic beads. Extraction of DNA by magnetic particles yielded high-quality DNA which was used in real-time quantitative PCR using an optimized set of primers. The method was highly sensitive as it was capable of detecting as little as 100 cfu of P. aeruginosa. It was also highly specific, as DNA extracted from other species of bacteria did not generate positive signals. Application of this novel rapid methodology to clinical samples yielded results identical to those obtained with traditional methods. Thus, the accumulated results demonstrate unequivocally that a novel rapid, sensitive, and specific method for detection of skin infections with P. aeruginosa was successfully developed and can be utilized clinically.

The complete mitochondrial genome of Blue-winged Minla (Minla cyanouroptera) and its phylogenetic analysis.

Blue-winged Minla is a small-sized bird, belonging to the Family Leiothrichidae of the Passeriformes. The population is suspected to be in decline owing to ongoing habitat destruction and fragmentation. Therefore, we sequenced and analyzed the Blue-winged Minla mitochondrial genome to provide a theoretical basis for protecting the brids. The mitochondrial genome of Blue-winged Minla was 17862 bp, it contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 2 control regions. The overall base composition of the mitochondrial was 30.88% A, 13.82% G, 23.86% T, 31.44% C.

Complete mitochondrial genome sequence of grey-headed parrotbill (Paradoxornis gularis) and its phylogenetic analysis.

Grey-headed Parrotbill, Paradoxornis gularis, has significant economic and scientific value in China. Length of the complete mitochondrial genome of grey-headed parrotbill is 17,743 bp, and it contains 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (12S rRNA and 16S rRNA), 22 transfer RNA genes (tRNA), and a D-loop sequence. The overall base composition of the mitochondrial sequence was 29.47% A, 14.68% G, 24.33% T, 31.52% C. All tRNAs have the typical cloverleaf structure, except for tRNASer . All PCGs start with ATG codons, except for COXI and NADH6, which are initiated by GTG and CTA, respectively.

Treponemal antibody in CSF and cellular immunity in peripheral blood of syphilitic patients with persisting positive rapid plasma regain.

The ratio of patients with RPR constant positive more than 2 years despite receiving standard syphilis treatment has been reported to be 11.54%~31.3%. The current interpretations on this phenomenon are cellular immune function restrained and the existence of neurosyphilis or asymptomatic neurosyphilis. We conducted this study to detect the treponemal antibody in cerebrospinal fluid (CSF) and lymphocyte subsets in peripheral blood of syphilis patients with persisting RPR positive more than 2 years without neurologic signs, and then explore their relationship. In this study, Treponemal antibody in CSF of 46 syphilitic with HIV negative were measured by syphilis serum test and compared with that of 5 neurosyphilis. Lymphocyte subsets were measured by flow cytometry (FCM) and compared with that of 30 healthy controls. We observed that treponemal antibody in CSF was detected not only in 12 cases (25.21%) of 46 treated patients, but also in 5 neurosyphilis. The ratio of lymphocyte subsets revealed that CD3+, CD4+ T cells and natural killer (NK) cells showed no significant differences between the patient and healthy controls (P>0.05), while CD8+ T cells in patients were significant higher than that in healthy controls (P<0.001). Lymphocyte subsets showed no significant differences between the patients with treponemal antibody positive and negative in CSF (P>0.05). In conclusion, the treponemal antibody in CSF of treated patients suggests that part of them were asymptomatic neurosyphilis and with cellular immunodifeciency. And there is no significant relationship between asymptomatic neurosyphilis and cellular immunodeficiency in peripheral blood.

Effects of extraction methods on the antioxidant activities of polysaccharides obtained from Flammulina velutipes.

Four polysaccharides (CFP, UFP, MFP and EFP) were extracted from Flammulina velutipes using hot water, ultrasonic, microwave or enzymatic methods optimized by orthogonal test. Preliminary structural characterizations were conducted using physicochemical properties. Polysaccharides extracted by all four methods showed similar physicochemical characteristics and FT-IR spectra. However, SEM images of tissues of F. velutipes were significantly different. EFP demonstrated better antioxidant activities against hydroxyl radical as well as improved metal chelating activity. UFP showed higher DPPH scavenging activity, but CFP exhibited higher antioxidant activity in reducing power. Hence, these polysaccharides can be used as natural antioxidants in functional foods or medicine. Further experiments on the biological activities of these four polysaccharides are currently in progress.

Antioxidant and hepatoprotective potential of endo-polysaccharides from Hericium erinaceus grown on tofu whey.

Three fractions of the endo-polysaccharides from the mycelium of Hericium erinaceus (HEP) grown on tofu whey were obtained by the fractional precipitation with gradient concentrations of ethanol (HEP40, HEP60 and HEP80). The chemical and physical characteristics of the three crude polysaccharides were investigated by the combination of chemical and instrumental analysis methods. The studies to evaluate the antioxidant potential and the hepatoprotective effects of the three polysaccharides showed that they had different activities in different evaluation system. HEP80 showed strong activity on antioxidant in vitro and potent hepatoprotective effect in vivo and the hepatoprotective effect may be due to its potent antioxidant capacity. The HEP could be exploited as antioxidant product and a supplement in the prevention of hepatic diseases. The study also opens an avenue for the efficient utilization of tofu whey, which is usually discarded in environment, causing concerns.

Direct evidence of Kerr-like nonlinearity by femtosecond Z-scan technique.

Kerr-like nonlinearity n(2) (THz) induced via terahertz (THz) radiation and linear electro-optic (EO) effect is investigated in (110), (111) and (100) oriented ZnTe crystals using Z-scan technique with femtosecond laser pulses. We have proposed a model, taking into account the Kerr-like nonlinearity n(2) (THz), to describe well the experimental incident polarization dependence of the nonlinear refractive index n(2). It is found that for a (110) ZnTe crystal the nonlinear refractive index n(2) is dominated by the Kerr-like nonlinearity n(2) (THz), while n(2) in the (111) ZnTe crystal mainly comes from the combined contributions of the Kerr-like nonlinearity n(2) (THz) and conventional Kerr nonlinearity n(2) (Kerr). We also show strong two-photon absorption (TPA) anisotropy and crystal orientation dependence of TPA in ZnTe crystals.