Young Seedling Stripe1 encodes a chloroplast nucleoid-associated protein required for chloroplast development in rice seedlings

Planta - Young Seedling Stripe1 (YSS1) was characterized as an important regulator of plastid-encoded plastid RNA polymerase (PEP) activity essential for chloroplast development at rice seedling...     

生姜精油化学成分及其抗菌活性

[背景]随着耐药微生物种类的增多和耐药性增强,抗耐药微生物新药的发现已成为全球关注的问题.生姜精油是纯天然植物精油,是天然抗菌材料的优选.[目的]分析生姜精油的化学成分,研究生姜精油对常见条件致病菌抗菌活性的影响,并阐明其可能的抗菌机制.[方法]采用气相色谱/质谱技术(Gas Chromatography/Mass S...     

产细菌素的细菌筛选鉴定及其产物抑菌性能研究

从水体改善制剂样品中筛选出一株产细菌素的芽孢杆菌XDF-2,经生理生化分析和分子生物学鉴定,确定为短小芽孢杆菌。发现该菌产细菌素受发酵时间和培养的影响。对该粗提的细菌素进行特性研究,发现该细菌素只对金黄色葡萄球菌和藤黄微球菌具有抑菌活性。但是该细菌素在不同pH、100℃以下的温度、表面活性剂和有机溶剂的环境下稳定。经酶解试验所得,推测该细菌素具有多肽结构和羧基酯的结构。     

Leptospirosis in pregnancy: A systematic review

IntroductionLeptospirosis is a leading zoonotic disease worldwide with more than 1 million cases in the general population per year. With leptospirosis being an emerging infectious disease and as the world’s environment changes with more floods and environmental disasters, the burden of leptospirosis is expected to increase. The objectives of the systematic review were to explore how leptospirosis affects pregnancy, its burden in this population, its effects on maternal and fetal outcomes and the evidence base surrounding treatment options.MethodsWe performed a systematic review of published and unpublished literature using automated and manual methods to screen nine electronic databases since inception, with no language restriction. Two reviewers independently screened articles, completed the data extraction and assessment of risk of bias. Due to significant heterogeneity and paucity of data, we were unable to carry out a meta-analysis, but we conducted a pooled analysis of individual patient data from the case reports and case series to examine the patient and disease characteristics, diagnostic methods, differential diagnoses, antibiotic treatments, and outcomes of leptospirosis in pregnancy. The protocol for this review was registered on the International Prospective Register of Systematic Reviews, PROSPERO: CRD42020151501.ResultsWe identified 419 records, of which we included eight observational studies, 21 case reports, three case series and identified four relevant ongoing studies. Overall the studies were with moderate bias and of ‘fair’ quality. We estimated the incidence of leptospirosis in pregnancy to be 1.3 per 10,000 in women presenting with fever or with jaundice, but this is likely to be higher in endemic areas. Adverse fetal outcomes were found to be more common in pregnant patients who presented in the second trimester compared with patients who presented in the third trimester. There is overlap between how leptospirosis presents in pregnancy and in the general population. There is also overlap between the signs, symptoms and biochemical disturbances associated with leptospirosis in pregnancy and the presentation of pregnancy associated conditions, such as Pre-Eclampsia (PET), Acute Fatty Liver of Pregnancy (AFLP) and HELLP Syndrome (Haemolysis Elevated Liver enzymes Low Platelets). In 94% of identified cases with available data, there was an indicator in the patient history regarding exposure that could have helped include leptospirosis in the clinician’s differential diagnosis. We also identified a range of suitable antibiotic therapies for treating leptospirosis in pregnancy, most commonly used were penicillins.ConclusionThis is the first systematic review of leptospirosis in pregnancy and it clearly shows the need to improve early diagnosis and treatment by asking early, treating early, and reporting well. Ask early—broaden differential diagnoses and ask early for potential leptospirosis exposures and risk factors. Treat early—increase index of suspicion in pregnant patients with fever in endemic areas and combine with rapid field diagnosis and early treatment. Report well—need for more good quality epidemiological studies on leptospirosis in pregnancy and better quality reporting of cases in literature.     

FLOURY ENDOSPERM6 encodes a CBM48 domain‐containing protein involved in compound granule formation and starch synthesis in rice endosperm

Starch is the most widespread form of energy storage in the plant kingdom. Although many enzymes and related factors have been identified for starch biosynthesis, unknown players remain to be identified, given that it is a complicated and sophisticated process. The endosperm of rice (Oryza sativa) has been used for the study of starch synthesis. Here, we report the cloning and characterization of the FLOURY ENDOSPERM6 (FLO6) gene in rice. In the flo6 mutant, the starch content is decreased and the normal physicochemical features of starch are changed. Significantly, flo6 mutant endosperm cells show obvious defects in compound granule formation. Map‐based cloning showed that FLO6 encodes a protein of unknown function. It harbors an N–terminal transit peptide that ensures its correct localization and functions in the plastid, and a C–terminal carbohydrate‐binding module 48 (CBM48) domain that binds to starch. Furthermore, FLO6 can interact with isoamylase1 (ISA1) both in vitro and in vivo, whereas ISA1 does not bind to starch directly. We thus propose that FLO6 may act as a starch‐binding protein involved in starch synthesis and compound granule formation through a direct interaction with ISA1 in developing rice seeds. Our data provide a novel insight into the role of proteins with the CBM48 domain in plant species.     

化妆品中耐热大肠菌群和金黄色葡萄球菌检测能力验证分析

为增强实验室竞争力,考察实验室检测水平,本实验室参加了ACAS-pT743(2019)化妆品耐热大肠菌群及金黄色葡萄球菌的检测能力验证.本次能力验证中实验室共接收了四个样品,按照《化妆品安全技术规范》2015版对样品展开检测,并采用关键生理生化指标对可疑菌落加以确定以及16 S rDNA序列测定方法对结果进行复确认.结...     

Young Leaf Chlorosis 1, a chloroplast-localized gene required for chlorophyll and lutein accumulation during early leaf development in rice

Chlorophyll (Chl) and lutein are the two most abundant and essential components in photosynthetic apparatus, and play critical roles in plant development. In this study, we characterized a rice mutant named young leaf chlorosis 1 (ylc1) from a ⁶⁰Co-irradiated population. Young leaves of the ylc1 mutant showed decreased levels of Chl and lutein compared to those of wild type, and transmission electron microscopy analysis revealed that the thylakoid lamellar structures were obviously loosely arranged. Whereas, the mutant turns green gradually and approaches normal green at the maximum tillering stage. The Young Leaf Chlorosis 1 (YLC1) gene was isolated via map-based cloning and identified to encode a protein of unknown function belonging to the DUF3353 superfamily. Complementation and RNA-interference tests confirmed the role of the YLC1 gene, which expressed in all tested rice tissues, especially in the leaves. Real-time PCR analyses showed that the expression levels of the genes associated with Chl biosynthesis and photosynthesis were affected in ylc1 mutant at different temperatures. In rice protoplasts, the YLC1 protein displayed a typical chloroplast location pattern. The N-terminal 50 amino acid residues were confirmed to be necessary and sufficient for chloroplast targeting. These data suggested that the YLC1 protein may be involved in Chl and lutein accumulation and chloroplast development at early leaf development in rice.     

A rice <Emphasis Type="Italic">White-stripe leaf3</Emphasis> (<Emphasis Type="Italic">wsl3</Emphasis>) mutant lacking an HD domain-containing protein affects chlorophyll biosynthesis and chloroplast development

Leaf-color mutants are ideal genetic materials for understanding the mechanism of chloroplast development and chlorophyll (Chl) biosynthesis. Here we isolated and identified a new leaf-color mutant of rice, named white-stripe leaf3 (wsl3), from a ⁶⁰Co-irradiated mutant pool. The wsl3 mutant displayed a visible white-stripe leaf in both young seedlings and flag leaves of mature plant. Chl content in homozygous wsl3 mutant was approximately 47% of that in the wild type. Besides, chloroplast development in the mutant was severely arrested. By a map-based cloning strategy, the wsl3 gene was finely confined to a 50.8 kb region on chromosome 1. Moreover, a 9-bp deletion was identified in the genomic region of LOC_Os01g01920, which encodes an HD (histidine and aspartic acid) domaincontaining protein. Genetic complementation confirmed that LOC_Os01g01920 could recover the lesion of wsl3 mutation. Real-time PCR analyses showed that the expression levels of WSL3 were the highest in young and flag leaves among various tissues, and most of the genes associated with Chl biosynthesis were significantly down-regulated in the wsl3 mutant. Meanwhile, in contrast to many nuclear gene-encoded phage-type RNA polymerase(s) (NEP) transcribed genes were up-regulated, most of plastid-encoded bacterialtype RNA polymerase (PEP) transcribed genes were downregulated. These results demonstrated that the WSL3 gene, as an HD domain-containing protein, is involved in chl biosynthesis and chloroplast development in rice.     

A putative plastidial adenine nucleotide transporter,BRITTLE1-3, plays an essential role in regulating chloroplast development in rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

Differentiation from proplastids into chloroplasts is a light- and energy-dependent process. How this process is regulated is still poorly understood at the molecular level. We herein report a new putative plastidial adenine nucleotide transporter, BRITTLE1-3 (referred to as OsBT1-3), encoded by the rice (Oryza sativa) White Stripe Leaf 2 (WSL2) gene. Loss of OsBT1-3 function results in defective chloroplast biogenesis, severely reduced photosynthetic efficiency, and finally a white stripe leaf phenotype in the first four leaves. The expression levels of genes related to chlorophyll biosynthesis and photosynthesis are drastically reduced, accompanied with over accumulation of reactive oxygen species (ROS) in the wsl2 mutant. OsBT1-3 is targeted to the chloroplasts and it expresses in almost all tissues in plants, especially in young leaves. OsBT1-3 consists of 419 amino acids and exhibits features of all mitochondrial carrier proteins, including a typical transmembrane-spanning domain and a highly conserved sequence motif designated as the ‘mitochondrial energy transfer signatures’. Phylogenetic analysis shows that OsBT1-3 is a putative plastidial adenine nucleotide transporter and is most closely related to ZmBT1-2. Together, these observations suggest that the new putative adenine nucleotide transporter, OsBT1-3, plays an essential role in regulating chloroplast biogenesis and maintenance of ROS homeostasis during rice seedling de-etiolation.