Advances in membrane-tethered NAC transcription factors in plants

Transcription factors are central components in cell signal transduction networks and are critical regulators for gene expression. It is estimated that approximately 10% of all transcription factors are membrane-tethered. MTFs (membrane-bound transcription factors) are latent transcription factors that are inherently anchored in the cellular membrane in a dormant form. When plants encounter environmental stimuli, they will be released from the membrane by intramembrane proteases or by the ubiquitin proteasome pathway and then were translocated to the nucleus. The capacity to instantly activate dormant transcription factors is a critical strategy for modulating diverse cellular functions in response to external or internal signals, which provides an important transcriptional regulatory network in response to sudden stimulus and improves plant survival. NTLs (NTM1-like) are a small subset of NAC (NAM, ATAF1/2, CUC2) transcription factors, which contain a conserved NAC domain at the N-terminus and a transmembrane domain at the C-terminus. In the past two decades, several NTLs have been identified from several species, and most of them are involved in both development and stress response. In this review, we review the reports and findings on NTLs in plants and highlight the mechanism of their nuclear import as well as their functions in regulating plant growth and stress response.

WRKY6 transcription factor modulates root potassium acquisition through promoting expression of AKT1 in Arabidopsis

Potassium (K+ ), being an essential macronutrient in plants, plays a central role in many aspects. Root growth is highly plastic and is affected by many different abiotic stresses including nutrient deficiency. The Shaker-type K+ channel Arabidopsis (Arabidopsis thaliana) K+ Transporter 1 (AKT1) is responsible for K+ uptake under both low and high external K+ conditions. However, the upstream transcription factor of AKT1 is not clear. Here, we demonstrated that the WRKY6 transcription factor modulates root growth to low potassium (LK) stress in Arabidopsis. WRKY6 showed a quick response to LK stress and also to many other abiotic stress treatments. The two wrky6 T-DNA insertion mutants were highly sensitive to LK treatment, whose primary root lengths were much shorter, less biomass and lower K+ content in roots than those of wild-type plants, while WRKY6-overexpression lines showed opposite phenotypes. A further investigation showed that WRKY6 regulated the expression of the AKT1 gene via directly binding to the W-box elements in its promoter through EMSA and ChIP-qPCR assays. A dual luciferase reporter analysis further demonstrated that WRKY6 enhanced the transcription of AKT1. Genetic analysis further revealed that the overexpression of AKT1 greatly rescued the short root phenotype of the wrky6 mutant under LK stress, suggesting AKT1 is epistatic to WRKY6 in the control of LK response. Further transcriptome profiling suggested that WRKY6 modulates LK response through a complex regulatory network. Thus, this study unveils a transcription factor that modulates root growth under potassium deficiency conditions by affecting the potassium channel gene AKT1 expression.

ANAC087 transcription factor positively regulates age-dependent leaf senescence through modulating the expression of multiple target genes in Arabidopsis

Leaf senescence is the final stage of leaf development and appropriate onset and progression of leaf senescence are critical for reproductive success and fitness. Although great progress has been made in identifying key genes regulating leaf senescence and elucidating the underlining mechanisms in the model plant Arabidopsis, there is still a gap to understanding the complex regulatory network. In this study, we discovered that Arabidopsis ANAC087 transcription factor (TF) positively modulated leaf senescence. Expression of ANAC087 was induced in senescing leaves and the encoded protein acted as a transcriptional activator. Both constitutive and inducible overexpression lines of ANAC087 showed earlier senescence than control plants, whereas T-DNA insertion mutation and dominant repression of the ANAC087 delayed senescence rate. A quantitative reverse transcription-polymerase chain reaction (qRT-PCR) profiling showed that the expression of an array of senescence-associated genes was upregulated in inducible ANAC087 overexpression plants including BFN1, NYE1, CEP1, RbohD, SAG13, SAG15, and VPEs, which are involved in programmed cell death (PCD), chlorophyll degradation and reactive oxygen species (ROS) accumulation. In addition, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) assays demonstrated that ANAC087 directly bound to the canonical NAC recognition sequence (NACRS) motif in promoters of its target genes. Moreover, mutation of two representative target genes, BFN1 or NYE1 alleviated the senescence rate of ANAC087-overexpression plants, suggesting their genetic regulatory relationship. Taken together, this study indicates that ANAC087 serves as an important regulator linking PCD, ROS, and chlorophyll degradation to leaf senescence.

The Abscisic Acid-Responsive Element Binding Factors (ABFs)-MAPKKK18 module regulates ABA- induced leaf senescence in Arabidopsis

The Mitogen-Activated Protein Kinase Kinase Kinase 18 (MAPKKK18) has been reported to play a role in abiotic stress priming in long-term abscisic acid (ABA) response including drought tolerance and leaf senescence. However, the upstream transcriptional regulators of MAPKKK18 remain to be determined. Here, we report ABA-Responsive Element (ABRE) Binding Factors (ABFs) as upstream transcription factors (TFs) of MAPKKK18 expression. Mutants of abf2, abf3, abf4 and abf2abf3abf4 dramatically reduced the transcription of MAPKKK18. Our electrophoresis mobility shift assay (EMSA) and dual-luciferase reporter assay demonstrated that ABF2, ABF3, and ABF4 bound to ABRE cis-elements within the promoter of MAPKKK18 to transactivate its expression. Furthermore, enrichments of the promoter region of MAPKKK18 by ABF2, ABF3, and ABF4 were confirmed by in vivo chromatin immunoprecipitation coupled with qPCR (ChIP-qPCR). Additionally, we found that mutants of mapkkk18 exhibited obvious delayed leaf senescence. Moreover, a genetic study showed that overexpression of ABF2, ABF3, and ABF4 in the background of mapkkk18 mostly phenocopied the stay-green phenotype of mapkkk18 and, expression levels of five target genes of ABFs, that is, NYE1, NYE2, NYC1, PAO, and SAG29 were attenuated as a result of MAPKKK18 mutation. These findings demonstrate that ABF2, ABF3, and ABF4 act as transcription regulators of MAPKKK18, and also suggest that, at least in part, ABA acts in priming leaf senescence via ABF-induced expression of MAPKKK18.

WRKY29 transcription factor regulates ethylene biosynthesis and response in arabidopsis

The gaseous phytohormone ethylene participates in a lot of physiological processes in plants. 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS, EC 4.4.1.14) and the ACC oxidase (ACO, EC 1.14.17.4) are key enzymes in ethylene biosynthesis. However, how ACSs and ACOs are regulated at the transcriptional level is largely unknown. In the present study, we showed that an Arabidopsis (Arabidopsis thaliana) WRKY-type transcription factor (TF), WRKY29 positively regulated the expression of ACS5, ACS6, ACS8, ACS11 and ACO5 genes and thus promoted basal ethylene production. WRKY29 protein was localized in nuclei and was a transcriptional activator. Overexpression of WRKY29 caused pleiotropic effect on plant growth, development and showed obvious response even without ACC treatment. Inducible overexpression of WRKY29 also reduced primary root elongation and lateral root growth. A triple response assay of overexpression and mutant seedlings of WRKY29 showed that overexpression seedlings had shorter hypocotyls than the transgenic GFP (Green Fluorescence Protein) control, while mutants had no difference from wild-type. A qRT-PCR assay demonstrated that expression of multiple ACSs and ACO5 was up-regulated in WRKY29 overexpression plants. A transactivation assay through dual luciferase reporter system confirmed the regulation of promoters of ACS5, ACS6, ACS8, ACS11 and ACO5 by WRKY29. Both in vivo chromatin immunoprecipitation (ChIP)- quantitative PCR and in vitro electrophoretic mobility shift assay (EMSA) revealed that WRKY29 directly bound to the promoter regions of its target genes. Taken together, these results suggest that WRKY29 is a novel TF positively regulating ethylene production by modulating the expression of ACS and ACO genes.

Rapeseed NAM transcription factor positively regulates leaf senescence via controlling senescence-associated gene expression

Leaf senescence is one of the most visible forms of programmed cell death in plants. It can be a seasonal adaptation in trees or the final stage in crops ensuring efficient translocation of nutrients to seeds. Along with developmental cues, various environmental factors could also trigger the onset of senescence through transcriptional cascades. Rapeseed (Brassica napus L.) is an important oil crop with its yielding affected by significant falling leaves as a result of leaf senescence, compared to many other crops. Therefore, a better understanding of leaf senescence and developing strategies controlling the progress of leaf senescence in rapeseed is necessary for warranting vegetable oil security. Here we functionally characterized the gene BnaNAM encoding No Apical Meristem (NAM) homologue to identify transcriptional regulation of leaf senescence in rapeseed. A combination of transient and stable expression techniques revealed overexpression of BnaNAM induced ROS production and leaf chlorosis. Quantitative evaluation of up-regulated genes in BnaNAM overexpression lines identified genes related to ROS production (RbohD, RbohF), proteases (βVPE, γVPE, SAG12, SAG15), chlorophyll catabolism (PaO, PPH) and nucleic acid degradation (BFN1) as the putative downstream targets. A dual luciferase-based transcriptional activation assay of selected promoters further confirmed BnaNAM mediated transactivation of promoters of the downstream genes. Finally, an electrophoretic mobility shift assay further confirmed direct binding of BnaNAM to promoters of βVPE, γVPE, SAG12, SAG15 and BFN1. Our results therefore demonstrate a novel role of BnaNAM in leaf senescence.

[The influencing factors of cognitive impairment in patients with silicosis]

Objective: To explore the influencing factors of cognitive impairment in patients with silicosis, and to analyze the effect of brain-derived neurotrophic factor (BDNF) on cognitive function. Methods: In March 2021, 484 silicosis patients from April 2018 to April 2020 were included in the study. The Montreal Cognitive Assessment Scale of Chinese version was used to evaluate their cognitive function, and they were divided into the cognitive impairment group (n=282) and the non cognitive impairment group (n=202) , another 30 healthy persons from body check were served as control group. The concentrations of BDNF were compared between the three groups. And the receiver operating characteristic (ROC) curve was drawed to analyze the value of BDNF in predicting cognitive impairment in silicosis patients. And the logistic regression analysis was used to explore the risk factors of cognitive impairment. Results: The incidence of cognitive impairment in silicosis patients was 58.26% (282/484) . The level of BDNF in the cognitive impairment group[ (10.32±2.11) mg/L] was significantly lower than that in the non cognitive impairment group[ (13.43±3.45) mg/L] (t=-12.27, P<0.001) . The results of ROC curve analysis showed that the area unde the curve of BDNF in predicting cognitive impairment of silicosis patients was 0.763 (95%CI: 0.613-0.874, P=0.024) , the cut off value was 10 mg/L, the sensitivity was 0.88, and the specificity was 0.84. Logistic regression analysis showed that the level of BDNF (≤10 mg/L) , age (≥65 years old) , course of disease (≥5 years) and diabetes mellitus were the risk factors of cognitive impairment in silicosis patients (OR=2.346, 95%CI: 1.654-3.103; OR=1.757, 95%CI: 1.214-1.998; OR=1.346, 95%CI: 1.112-1.564; OR=1.165, 95%CI: 1.102-1.542, P=0.001, 0.012, 0.027, 0.036) . Conclusion: BDNF may be one of the indicator to predict the risk of cognitive impairment in patients with silicosis.

Calcium-dependent Protein Kinase 5 (CPK5) positively modulates drought tolerance through phosphorylating ABA-Responsive Element Binding Factors in oilseed rape (Brassica napus L.)

Drought is an environmental stress that causes severe crop loss. Drought stress can induce abscisic acid (ABA) accumulation and cytoplasmic calcium oscillation. Calcium-dependent protein kinases (CPKs) constitute a group of Ser/Thr protein kinases decoding calcium signals. However, the function and molecular mechanisms of most CPKs in oilseed rape (Brassica napus) remain unknown. Here, we report the functional characterization of BnaCPK5 in drought stress tolerance. BnaCPK5 belongs to Group I of the CPK family and was localized at the plasma membrane and nuclei. Overexpression of BnaCPK5 enhanced drought stress tolerance compared with the control. A screening of interacting proteins identified that BnaCPK5 interacted strongly with two ABA-Responsive Element Binding Factors (ABF/AREBs), BnaABF3 and BnaABF4. BnaCPK5 was shown to phosphorylate both BnaABF3 and BnaABF4 in a kinase assay. Further, it was found that the phosphorylation of BnaABF3 and BnaABF4 by BnaCPK5 increased their transcriptional activities against the famous drought stress marker gene, Responsive to Dehydration (RD) 29B and protein stability. Taken together, these data demonstrate that BnaCPK5 acts as a positive regulator of drought tolerance by, at least in part, phosphorylating two core ABA-signaling components to modulate Late-Embryogenesis Abundant (LEA)-like RD29B expression.

[Investigation and analysis of 3021 cases of occupational hand injury in Xiaoshan District, Hangzhou]

Objective: To investigate the causes and characteristics of occupational hand trauma in Xiaoshan District of Hangzhou, and to provide basis for formulating preventive measures and treatment. Methods: In July 2020, 3021 patients with occupational hand injury treated in Xiaoshan District from January 2017 to December 2019 were selected as the research object. The data of gender, age, injury month and time period of patients with occupational hand injury were collected, and their relationship with the causes of injury was analyzed. Results: Among 3021 patients with occupational hand trauma in Xiaoshan District, most of them were men (male to female ratio 2.05∶1) , and the proportion of injuries from 18 to 30 years old was relatively high (1508 cases, 49.92%) . The proportion of patients with cutting injury was high (1208 cases, 39.99%) , most of the injuries were at the distal end of metacarpophalangeal joint (2118 cases, 70.11%) , the proportion of injuries in summer was relatively high (1225 cases, 40.55%) . Most of them were injured from 8:00 to 16:00 every day (1684 cases, 55.74%) , of which 11:00-12:00 accounted for 29.46% (890 cases) . The excellent and good rate of functional recovery in all patients was 85.10% (2571/3021) . There were significant differences in the distribution of injury causes among patients with occupational hand trauma in different gender, age and seasons (P<0.01) . Conclusion: In Xiaoshan District of Hangzhou, there are many cases of cutting injuries in patients with occupational hand injuries, with high incidence in summer and 11:00-12:00. Enterprises should strengthen the supervision and management of relevant time periods, especially to prevent the occurrence of cutting injuries.

Membrane-Bound Transcriptional Activator NTL1 from Rapeseed Positively Modulates Leaf Senescence through Targeting Genes Involved in Reactive Oxygen Species Production and Programmed Cell Death

Leaf senescence is the last stage of leaf development and is determined by various environmental and endogenous signals. Leaf senescence can determine plant productivity and fitness. Transcription factors (TFs) with the transmembrane domain constitute a special group of regulatory proteins that can translocate from the membrane system into nuclei to exert the transcriptional function upon endogenous or exogenous stimuli. Reactive oxygen species (ROSs) play an important role in numerous processes throughout the life cycle of plants including leaf senescence. Leaf senescence is characterized by massive programmed cell death (PCD) and is a type of developmental PCD. The transcriptional regulatory relationships between membrane-bound TFs and leaf senescence remain largely uncharacterized, especially in rapeseed (Brassica napus L.), an important oil crop. Here, we show that BnaNTL1 is a membrane-bound NAC (NAM, ATAF, and CUC) TF, which is predominantly expressed in senescent leaves. Expression of BnaNTL1ΔTM, a form of BnaNTL1 devoid of the transmembrane domain, can induce serious HR-like cell death symptoms and ROS accumulation in cells. Plants overexpressing BnaNTL1ΔTM show earlier leaf senescence compared with the control, accompanied by chlorophyll degradation and electrolyte leakage. Genes involved in ROS production (RbohD), PCD (VPEs and CEP1), and leaf senescence (BFN1) are significantly induced and activated by BnaNTL1ΔTM according to the quantitative reverse transcription PCR (qRT-PCR) analysis and dual luciferase reporter (Dual-LUC) assay. Moreover, electrophoretic mobility shift assay revealed that BnaNTL1 directly bound to the NTLBS elements in promoters of RbohD, γVPE, and BFN1. In conclusion, these results demonstrate that BnaNTL1 positively modulates ROS production and HR-like cell death to induce leaf senescence.

[Clinical efficacy of stent-assisted coil embolization for recurrent intracranial bifurcation aneurysms]

Objective: To evaluate the safety and efficacy of stent-assisted coil embolization in patients with recurrent intracranial bifurcation aneurysms,after initial simple coiling or microsurgical clipping. Methods: Clinical data of 20 patients with recurrent intracranial bifurcation aneurysms who initially underwent simple coiling or surgical clipping and subsequently re-treated by stent-assisted coiling embolization at the Radiology Intervention Department of Huashan Hospital between March 2009 and November 2019 were collected and analyzed retrospectively.There were 9 males and 11 females,with a median age of 55.5 years (range:33 to 71 years),including 17 aneurysms initially treated with simple coiling and 3 treated with surgical clipping.All cases were re-treated with stent-assisted coiling,15 using a single stent and 5 employing two stents in a Y-configuration.Peri-and post-operative complications and outcomes were evaluated.Mann-Whitney U tests were performed to compare the follow-up duration between initial treatment and re-treatment.Student's t tests were used to compare the parent artery angles before re-treatment, after re-treatment and at the last follow-up. The parent artery angle was defined using the proximal main trunk and the stented branch. Results: Immediate complete occlusion (Raymond Ⅰ) was achieved in 18 aneurysms (90.0%) while 2 aneurysms (10.0%) had a residual neck (Raymond Ⅱ).The median follow-up time(M(Q_R)) was 8.5(16.3)months,which had no significantly different from the initial treatment follow-up duration (15.5(27.0)months)(U=157.7,P=0.25). During the follow-up period,2 aneurysms (10.0%) with immediate post-operative residual necks recanalized again,including 1 aneurysm re-treated with the Y-configuration stent.Symptomatic thromboembolic complications occurred in 6 patients,including 4 re-treated with the Y-configuration stent.No peri-operative hemorrhagic complications occurred,along with no operation-related permanent disability or death. The parent artery angle increased significantly from pre-operative(90.1±21.1)°to post-operative and the last follow-up ((115.4±28.9)° and (132.6±26.8)°);t=5.14,P<0.01;t=7.78,P<0.01). Conclusion: For recurrent intracranial bifurcation aneurysms after initial surgical clipping or simple coiling,stent assisted coil embolization is proved to be safe and can decrease recurrence rate.

[Baseline characteristics of the participants of China National Birth Cohort]

Objective: To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception. Methods: The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth. Results: By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions. Conclusion: CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.

[A sub-cohort study design of the maternal and infant microbes in China National Birth Cohort]

The importance of gut microbes to human health has gradually attracted attention. With the use of animal models, it has been revealed that maternal microbes during pregnancy could influence their children's health outcomes through shaping their microbial composition and regulating the development of their metabolic and immune system. However, the physiological mechanism of the human body is more complex and is affected by the interaction of multiple factors. The research results obtained from animal models are often inconsistent with human studies. At present, the influence of maternal intestinal microbes during pregnancy on the microbial colonization in their offspring and on a series of children's health outcomes is still unclear. Establishing a sub-cohort to detect the microbiome of the women across pregnancy and of their offspring, and further to integrate with variety of environmental and behavioral exposures can better provide reliable support for the research on the mechanism of children's health and diseases. This paper briefly introduces the research objectives, content, progress, strength and limitations of the sub-cohort study.

[The Autism Spectrum Disorder Cohort-the sub-cohort of China National Birth Cohort]

Autism spectrum disorder (ASD), a representative disease of children's neurodevelopmental disorders, brings huge pressure and financial burden to families and society. It is of great significance to explore its etiology and pathogenesis. Therefore, we established an ASD Cohort based on the existing China National Birth Cohort (CNBC), which applied parallel design to recruit and follow up families who achieved pregnancy after receiving assisted reproductive technologies (ART) and families with spontaneous conception. The main aims of this study are to compare the incidence of ASD among children born after ART with those born under spontaneous pregnancy, and to evaluate the impact of ART on the neurobehavioral development of offspring. Additionally, with a variety of clinical and behavioral related information collected during pregnancy and at early life of offspring, we are able to investigate the risk factors associated with ASD comprehensively. This article briefly introduces the objectives, contents, preliminary progress, strength and limitations, as well as further prospects of the ASD cohort study, mainly focusing on the overall design and current progress.

[Quality control and measures of China National Birth Cohort]

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.

Ectopic overexpression of a membrane-tethered transcription factor gene NAC60 from oilseed rape positively modulates programmed cell death and age-triggered leaf senescence

Senescence is an integrative final stage of plant development that is governed by internal and external cues. The NAM, ATAF1/2, CUC2 (NAC) transcription factor (TF) family is specific to plants and membrane-tethered NAC TFs (MTTFs) constitute a unique and sophisticated mechanism in stress responses and development. However, the function of MTTFs in oilseed rape (Brassica napus L.) remains unknown. Here, we report that BnaNAC60 is an MTTF associated with the endoplasmic reticulum (ER) membrane. Expression of BnaNAC60 was induced during the progression of leaf senescence. Translocation of BnaNAC60 into nuclei was induced by ER stress and oxidative stress treatments. It binds to the NTLBS motif, rather than the canonical NAC recognition site. Overexpression of BnaNAC60 devoid of the transmembrane domain, but not the full-length BnaNAC60, induces significant reactive oxygen species (ROS) accumulation and hypersensitive response-like cell death in both tobacco (Nicotiana benthamiana) and oilseed rape protoplasts. Moreover, ectopic overexpression of BnaNAC60 devoid of the transmembrane domain, but not the full-length BnaNAC60, in Arabidopsis also induces precocious leaf senescence. Furthermore, screening and expression profiling identified an array of functional genes that are significantly induced by BnaNAC60 expression. Further it was found that BnaNAC60 can activate the promoter activities of BnaNYC1, BnaRbohD, BnaBFN1, BnaZAT12, and multiple BnaVPEs in a dual-luciferase reporter assay. Electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative PCR assays revealed that BnaNAC60 directly binds to the promoter regions of these downstream target genes. To summarize, our data show that BnaNAC60 is an MTTF that modulates cell death, ROS accumulation, and leaf senescence.

WRKY42 transcription factor positively regulates leaf senescence through modulating SA and ROS synthesis in Arabidopsis thaliana

Leaf senescence represents the final stage of leaf growth and development, and its onset and progression are strictly regulated; however, the underlying regulatory mechanisms remain largely unknown. In this study we found that WRKY42 was highly induced during leaf senescence. Loss-of-function wrky42 mutants showed delayed leaf senescence whereas the overexpression of WRKY42 accelerated senescence. Transcriptome analysis revealed 2721 differentially expressed genes between wild-type and WRKY42-overexpressing plants, including genes involved in salicylic acid (SA) and reactive oxygen species (ROS) synthesis as well as several senescence-associated genes (SAGs). Moreover, WRKY42 activated the transcription of isochorismate synthase 1 (ICS1), respiratory burst oxidase homolog F (RbohF) and a few SAG genes. Consistently, the expression of these genes was reduced in wrky42 mutants but was markedly increased in transgenic Arabidopsis overexpressing WRKY42. Both in vitro electrophoretic mobility shift assays (EMSAs) and in vivo chromatin immunoprecipitation and dual luciferase assays demonstrated that WRKY42 directly bound to the promoters of ICS1 and RbohF, as well as a few SAGs, to activate their expression. Genetic analysis further showed that mutations of ICS1 and RbohF suppressed the early senescence phenotype evoked by WRKY42 overexpression. Thus, we have identified WRKY42 as a novel transcription factor positively regulating leaf senescence by directly activating the transcription of ICS1, RbohF and SAGs, without any seed yield penalty.

WRKY55 transcription factor positively regulates leaf senescence and the defense response by modulating the transcription of genes implicated in the biosynthesis of reactive oxygen species and salicylic acid in Arabidopsis

Reactive oxygen species (ROS) and salicylic acid (SA) are two factors regulating leaf senescence and defense against pathogens. However, how a single gene integrates both ROS and SA pathways remains poorly understood. Here, we show that Arabidopsis WRKY55 transcription factor positively regulates ROS and SA accumulation, and thus leaf senescence and resistance against the bacterial pathogen Pseudomonas syringae WRKY55 is predominantly expressed in senescent leaves and encodes a transcriptional activator localized to nuclei. Both inducible and constitutive overexpression of WRKY55 accelerates leaf senescence, whereas mutants delay it. Transcriptomic sequencing identified 1448 differentially expressed genes, of which 1157 genes are upregulated by WRKY55 expression. Accordingly, the ROS and SA contents in WRKY55-overexpressing plants are higher than those in control plants, whereas the opposite occurs in mutants. Moreover, WRKY55 positively regulates defense against P. syringae Finally, we show that WRKY55 activates the expression of RbohD, ICS1, PBS3 and SAG13 by binding directly to the W-box-containing fragments. Taken together, our work has identified a new WRKY transcription factor that integrates both ROS and SA pathways to regulate leaf senescence and pathogen resistance.

A Rapeseed WRKY Transcription Factor Phosphorylated by CPK Modulates Cell Death and Leaf Senescence by Regulating the Expression of ROS and SA-Synthesis-Related Genes

Salicylic acid (SA) and reactive oxygen species (ROS) are two well-defined inducers of leaf senescence. Here, we identified a novel WRKY transcription factor gene WSR1 (WRKY regulating SA and ROS 1) in Brassica napus (rapeseed) in promoting SA and ROS production, which eventually led to leaf senescence thereafter. Its expression increased in senescing leaves. Ca²⁺-dependent protein kinase (CPK) 5 and -6 interacted with and phosphorylated BnaWSR1. Overexpression of phosphomimic BnaWSR1 (BnaWSR1ca) in rapeseed protoplasts elicited ROS production and cell death while its ectopic expression in Arabidopsis enhanced SA and ROS levels and, hence, accelerated leaf senescence. Furthermore, BnaWSR1ca activated the expression of Isochorismate Synthase 1 (ICS1), Respiratory Burst Oxidase Homologue (Rboh) D, and Senescence-Associated Gene 14 (SAG14). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) assays demonstrated that BnaWSR1ca directly bound to promoter regions of ICS1, RbohD, and SAG14. These data have identified a CPK-WSR1 module that integrates SA and ROS to control cell death and leaf senescence.

The R2R3-MYB transcription factor BnaMYB111L from rapeseed modulates reactive oxygen species accumulation and hypersensitive-like cell death

As one of the largest families of transcription factors in plants, the R2R3-MYB proteins play important roles in diverse biological processes including growth and development, primary and secondary metabolism such as flavonoid and anthocyanin biosynthesis as well as abiotic and biotic stress responses. However, functions of R2R3-MYB genes in rapeseed (Brassica napus L.) remain elusive. Here, we characterized BnaMYB111L, which is homologous to Arabidopsis MYB111 and encodes an R2R3-MYB protein in rapeseed. BnaMYB111L is responsive to abscisic acid (ABA), heat, cold, hydrogen peroxide and fungal pathogen Sclerotinia scelerotiorum treatments through quantitative RT-PCR assay. BnaMYB111L encodes a transcriptional activator and is localized exclusively to nuclei. Interestingly, overexpression of BnaMYB111L in tobacco (Nicotiana benthamiana) and rapeseed protoplasts promoted reactive oxygen species (ROS) production and hypersensitive response-like cell death, accumulation of malondialdehyde (MDA) as well as degradation of chlorophyll. Furthermore, BnaMYB111L expression evoked the alterations of transcript levels of genes encoding ROS-producing enzyme, vacuolar processing enzymes and genes implicated in defense responses. A further dual luciferase reporter assay indicated that BnaMYB111L activated the expression of RbohB, MC4 and ACRE132, which are involved in ROS generation, cell death as well as defense responses. Taken together, this study characterized the function of rapeseed MYB111L and identified its putative target genes involved in ROS production and cell death.

Arabidopsis CPK6 positively regulates ABA signaling and drought tolerance through phosphorylating ABA-responsive element-binding factors

Abscisic acid (ABA) regulates numerous developmental processes and drought tolerance in plants. Calcium-dependent protein kinases (CPKs) are important Ca2+ sensors playing crucial roles in plant growth and development as well as responses to stresses. However, the molecular mechanisms of many CPKs in ABA signaling and drought tolerance remain largely unknown. Here we combined protein interaction studies, and biochemical and genetic approaches to identify and characterize substrates that were phosphorylated by CPK6 and elucidated the mechanism that underlines the role of CPK6 in ABA signaling and drought tolerance. The expression of CPK6 is induced by ABA and dehydration. Two cpk6 T-DNA insertion mutants are insensitive to ABA during seed germination and root elongation of seedlings; in contrast, overexpression of CPK6 showed the opposite phenotype. Moreover, CPK6-overexpressing lines showed enhanced drought tolerance. CPK6 interacts with and phosphorylates a subset of core ABA signaling-related transcription factors, ABA-responsive element-binding factors (ABFs/AREBs), and enhances their transcriptional activities. The phosphorylation sites in ABF3 and ABI5 were also identified through MS and mutational analyses. Taken together, we present evidence that CPK6 mediates ABA signaling and drought tolerance through phosphorylating ABFs/AREBs. This work thus uncovers a rather conserved mechanism of calcium-dependent Ser/Thr kinases in ABA signaling.

Rapeseed calcium-dependent protein kinase CPK6L modulates reactive oxygen species and cell death through interacting and phosphorylating RBOHD

Reactive oxygen species (ROS) play important roles in plant growth, development, responses to abiotic and biotic stresses. Hypersensitive response (HR)-like cell death is often associated with excess ROS. However, how a calcium-dependent protein kinase (CPK) modulates this process remains elusive in rapeseed (Brassica napus L.). In the present study, we identified and characterized CPK6L from rapeseed as a novel regulator of ROS and cell death. The subcellular localization of BnaCPK6L was investigated through GFP and was found to be located at the endoplasmic reticulum membrane. Overexpression of the constitutively active BnaCPK6LCA resulted in significant accumulation of ROS and HR-like cell death than the full-length. A quantitative RT-PCR survey identified that the expression levels of a few ROS, cell death and defense-related marker genes were up-regulated upon BnaCPK6LCA expression. Mating-based split ubiquitin system (mbSUS) screening revealed that BnaCPK6L interacted with BnaRBOHD (Respiratory Burst Oxidase Homolog D), which was validated by bimolecular fluorescence complementation (BiFC). An in vitro phosphorylation assay indicated that BnaCPK6L phosphorylated BnaRBOHD. Lastly, we also found that three 2C type protein phosphatases (PP2Cs) interacted with BnaCPK6L. Taken together, this study indicates that BnaCPK6L plays an important role in ROS and HR-like cell death through interacting with and phosphorylating RBOHD.

Recognizing basal cell carcinoma on smartphone-captured digital histopathology images with a deep neural network

BACKGROUND

Pioneering effort has been made to facilitate the recognition of pathology in malignancies based on whole-slide images (WSIs) through deep learning approaches. It remains unclear whether we can accurately detect and locate basal cell carcinoma (BCC) using smartphone-captured images.

OBJECTIVES

To develop deep neural network frameworks for accurate BCC recognition and segmentation based on smartphone-captured microscopic ocular images (MOIs).

METHODS

We collected a total of 8046 MOIs, 6610 of which had binary classification labels and the other 1436 had pixelwise annotations. Meanwhile, 128 WSIs were collected for comparison. Two deep learning frameworks were created. The 'cascade' framework had a classification model for identifying hard cases (images with low prediction confidence) and a segmentation model for further in-depth analysis of the hard cases. The 'segmentation' framework directly segmented and classified all images. Sensitivity, specificity and area under the curve (AUC) were used to evaluate the overall performance of BCC recognition.

RESULTS

The MOI- and WSI-based models achieved comparable AUCs around 0·95. The 'cascade' framework achieved 0·93 sensitivity and 0·91 specificity. The 'segmentation' framework was more accurate but required more computational resources, achieving 0·97 sensitivity, 0·94 specificity and 0·987 AUC. The runtime of the 'segmentation' framework was 15·3 ± 3·9 s per image, whereas the 'cascade' framework took 4·1 ± 1·4 s. Additionally, the 'segmentation' framework achieved 0·863 mean intersection over union.

CONCLUSIONS

Based on the accessible MOIs via smartphone photography, we developed two deep learning frameworks for recognizing BCC pathology with high sensitivity and specificity. This work opens a new avenue for automatic BCC diagnosis in different clinical scenarios. What's already known about this topic? The diagnosis of basal cell carcinoma (BCC) is labour intensive due to the large number of images to be examined, especially when consecutive slide reading is needed in Mohs surgery. Deep learning approaches have demonstrated promising results on pathological image-related diagnostic tasks. Previous studies have focused on whole-slide images (WSIs) and leveraged classification on image patches for detecting and localizing breast cancer metastases. What does this study add? Instead of WSIs, microscopic ocular images (MOIs) photographed from microscope eyepieces using smartphone cameras were used to develop neural network models for recognizing BCC automatically. The MOI- and WSI-based models achieved comparable areas under the curve around 0·95. Two deep learning frameworks for recognizing BCC pathology were developed with high sensitivity and specificity. Recognizing BCC through a smartphone could be considered a future clinical choice.

An oilseed rape WRKY-type transcription factor regulates ROS accumulation and leaf senescence in Nicotiana benthamiana and Arabidopsis through modulating transcription of RbohD and RbohF

MAIN CONCLUSION

Overexpression of BnaWGR1 causes ROS accumulation and promotes leaf senescence. BnaWGR1 binds to promoters of RbohD and RbohF and regulates their expression. Manipulation of leaf senescence process affects agricultural traits of crop plants, including biomass, seed yield and stress resistance. Since delayed leaf senescence usually enhances tolerance to multiple stresses, we analyzed the function of specific MAPK-WRKY cascades in abiotic and biotic stress tolerance as well as leaf senescence in oilseed rape (Brassica napus L.), one of the important oil crops. In the present study, we showed that expression of one WRKY gene from oilseed rape, BnaWGR1, induced an accumulation of reactive oxygen species (ROS), cell death and precocious leaf senescence both in Nicotiana benthamiana and transgenic Arabidopsis (Arabidopsis thaliana). BnaWGR1 regulates the transcription of two genes encoding key enzymes implicated in production of ROS, that is, respiratory burst oxidase homolog (Rboh) D and RbohF. A dual-luciferase reporter assay confirmed the transcriptional regulation of RbohD and RbohF by BnaWGR1. In vitro electrophoresis mobility shift assay (EMSA) showed that BnaWGR1 could bind to W-box cis-elements within promoters of RbohD and RbohF. Moreover, RbohD and RbohF were significantly upregulated in transgenic Arabidopsis overexpressing BnaWGR1. In summary, these results suggest that BnaWGR1 could positively regulate leaf senescence through regulating the expression of RbohD and RbohF genes.

A Novel NAC-Type Transcription Factor, NAC87, from Oilseed Rape Modulates Reactive Oxygen Species Accumulation and Cell Death

Reactive oxygen species (ROS) are thought to play a dual role in plants by functioning as signaling molecules and toxic by-products of aerobic metabolism. The hypersensitive response (HR) is a typical feature of immune responses in plants and also a type of programmed cell death (PCD). How these two processes are regulated in oilseed rape (Brassica napus L.) at the transcriptional level remains largely unknown. In this study, we report that an oilseed rape (Brassica napus L.) NAM-ATAF-CUC (NAC)-type transcription factor NAC87 modulates ROS and cell death accompanied by typical changes at the morphological and cellular levels. The BnaNAC87 gene was induced by multiple stress and hormone treatments and was highly expressed in senescent leaves by quantitative reverse transcription-PCR (qRT-PCR). BnaNAC87 is located in nuclei and has transcriptional activation activity. Expression of BnaNAC87 promoted significant ROS production, cell death as well as death of protoplasts, as indicated by histological staining. In addition, putative downstream target genes of NAC87 were identified through both qRT-PCR and dual luciferase reporter assays. We found that genes implicated in ROS generation (RbohB), cell death (VPE1a, ZEN1), leaf senescence (WRKY6, ZAT12) and defense (PR2, PR5 and HIN1) were significantly induced. Through an electrophoretic mobility shift assay (EMSA), we confirmed that BnaNAC87 directly binds to the NACRS-containing promoter fragments of ZEN1, ZAT12, HIN1 and PR5 genes. From these results, we conclude that oilseed rape NAC87 is a novel NAC transcription factor that acts as a positive regulator of ROS metabolism and cell death.

[Preparation of chaperone-antigen peptide vaccine derived from human gastric cancer stem cells and its immune function]

Objective: To explore the method of extracting chaperone antigen peptide complexes from gastric cancer stem cells and its immune function. Methods: Gastric cancer stem cells and gastric cancer cells were screened by low temperature ultrasonic lysis. After salting out and dialysis, the lysate supernatant was processed with SDS-PAGE to analyze the expression of chaperone antigen peptide complexes, and then was separated and purified with CNBr-activated SepharoseTM 4B. Reverse high pressure liquid chromatography (HPLC), SDS-PAGE and Western blotting were used to analyze the purity and nature of the acquired albumen. Lymphocyte proliferation assay and lymphocytotoxicity assay were used to ditermine the immunological activity of the chaperone-antigen peptide complexes. Results: The chaperone antigen peptide complexes of gastric cancer stem cells were prepared and identified successfully, of which the main components were the antigen peptides of HSP60, HSP70, HSP90 and HSP110. 0.75 μg and 1.00 μg HSP70-antigen peptide and 1.00 μg HSP90-antigen peptide activated lymphocytes significantly. Their A(490) values were 0.26±0.03, 0.45±0.05 and 0.32±0.04, respectively, while the corresponding doses of HSP60-antigen peptide and HSP110-antigen peptide did not activate lymphocytes. The killing rates of 1.00 μg HSP70-antigen peptide and 1.00 μg HSP70 were (45.0±2.0)% and (16.0±2.0)%, respectively, showing a significant difference (P=0.012). Similarly, the killing rates of 1.00 μg HSP90-antigen peptide and 1.00 μg HSP90 were (36.0±5.0)% and (13.0±4.0)%, respectively, also showing a significant difference (P=0.048). Conclusions: The amount of chaperone antigen peptide complexes in gastric cancer cells is extremely low, but it is obviously increased in gastric cancer stem cells. After purification, the chaperone antigen peptide complexes with high purity can be prepared. The extracted chaperone antigen peptide complexes have stronger immunogenicity, and can be used to make tumor vaccine in vitro, which may have a good application value in the targeted therapy of gastric cancer.

Oilseed rape NAC56 transcription factor modulates reactive oxygen species accumulation and hypersensitive response-like cell death

The NAC (NAM, ATAF1/2, CUC2) transcription factor gene family is plant-specific and plays diverse roles in development and responses to abiotic stresses and pathogen challenge. Oilseed rape (Brassica napus) or canola is an important oil crop worldwide, however, the function of NAC genes in it remains largely elusive. In the present study, we identified and characterized the NAC56 gene isolated from oilseed rape. Expression of BnaNAC56 was induced by abscisic acid (ABA), jasmonic acid (JA), methyl viologen (MV) and a necrotrophic fungal pathogen Sclerotinia sclerotiorum, but repressed by cold. BnaNAC56 is a transcription activator and localized to nuclei. Overexpression of BnaNAC56 induced reactive oxygen species (ROS) accumulation and hypersensitive response (HR)-like cell death, with various physiological measurements supporting these. Furthermore, BnaNAC56 expression caused evident nuclear DNA fragmentation. Moreover, quantitative reverse transcription PCR (qRT-PCR) analysis identified that the expression levels of multiple genes regulating ROS homeostasis, cell death and defense response were significantly induced. Using a dual luciferase reporter assay, we further confirmed that BnaNAC56 could activate the expression of a few ROS- and cell death-related genes. In summary, our data demonstrate that BnaNAC56 functions as a stress-responsive transcriptional activator and plays a role in modulating ROS accumulation and cell death.

A novel HLA-B allele: HLA-B*40:242

The HLA-B*40:242 allele differs from B*40:54 by 1 nucleotide substitution at position 190.

Characterization of the novel HLA-DRB1*11:01:20 allele

The HLA- DRB1*11:01:20 allele differs from DRB1*11:01:01:01 by 1 nucleotide substitution at position 219.

Identification of a novel HLA-DRB1*14 allele, HLA-DRB1*14:127:01, in a Chinese Individual

Two nucleotide changes in codon 77 (ACC → AAT) of HLA-DRB1*14:05:03 result in the allele, HLA-DRB1*14:127:01.

Functional characterization of NAC55 transcription factor from oilseed rape (Brassica napus L.) as a novel transcriptional activator modulating reactive oxygen species accumulation and cell death

NAC transcription factors (TFs) are plant-specific and play important roles in development, responses to biotic and abiotic cues and hormone signaling. So far, only a few NAC genes have been reported to regulate cell death. In this study, we identified and characterized a NAC55 gene isolated from oilseed rape (Brassica napus L.). BnaNAC55 responds to multiple stresses, including cold, heat, abscisic acid (ABA), jasmonic acid (JA) and a necrotrophic fungal pathogen Sclerotinia sclerotiorum. BnaNAC55 has transactivation activity and is located in the nucleus. BnaNAC55 is able to form homodimers in planta. Unlike ANAC055, full-length BnaNAC55, but not either the N-terminal NAC domain or C-terminal regulatory domain, induces ROS accumulation and hypersensitive response (HR)-like cell death when expressed both in oilseed rape protoplasts and Nicotiana benthamiana. Furthermore, BnaNAC55 expression causes obvious nuclear DNA fragmentation. Moreover, quantitative reverse transcription PCR (qRT-PCR) analysis identified that the expression levels of multiple genes regulating ROS production and scavenging, defense response as well as senescence are significantly induced. Using a dual luciferase reporter assay, we further confirm that BnaNAC55 could activate the expression of a few ROS and defense-related gene expression. Taken together, our work has identified a novel NAC TF from oilseed rape that modulates ROS accumulation and cell death.

A novel HLA-B allele, HLA-B*13:69

HLA-B*13:69 allele differs from B*13:02:01 by one nucleotide substitution at position 628 from A to C.

[The application of the three-step approach based on the regional distribution of hepatic vessel in laparoscopic hemihepatectomy]

OBJECTIVE

To investigate the clinical significance of the three-step approach in laparoscopic hemihepatectomy.

METHODS

A total of 32 patients received laparoscopic hemihepatectomy with the three-step approach in Yijishan Hospital affiliated to Wannan Medical College between Aug 2013 and Oct 2015. All patients underwent thin slice CT scan and hemihepatectomy was imitated with the imagic explorer, preoperatively. The vessel distribution was observed at the section and the three-step approach was used in the hemihepatectomy. Pre- and post-operative data were collected and analyzed retrospectively.

RESULTS

The length of middle hepatic vein (MHV) was (59.1±12.9) mm and the number of branchs to the left and right lobe were 3.07±0.78 and 3.11±0.64 respectively. The distance between the first branch of MHV and the diaphragmatic surface was (28.07±3.74) mm and the distance between MHV and the visceral surface was (14.4±4.3) mm. The laparoscopic surgeries (left hemihepatectomy in 28 and right hemihepatectomy in 4) were performed successfully in all cases with the three-step approach, without any conversion to the open surgeries. The operation time was (165±42) min in left hemihepatectomy and (305±50) min in right hemihepatectomy. The intraoperative blood loss was (242±65) ml in left hemihepatectomy and (695±122)ml in right hemihepatectomy. All the patients recovered well without severe complications except for bile leakage in 3 patients who were cured with drainage. The postoperative hospital stay was (7.96±1.8) d.

CONCLUSIONS

the distribution of vessel is regional at the section of hemihepatectomy and the three-step approach based on this feature is safe and effective in laparoscopic hemihepatectomy, which can shorten the operation time and reduce the difficulty of operation.

A novel HLA-B allele, HLA-B*56:40

HLA-B*56:40 allele differs from B*56:01:01:01 by one nucleotide substitution at position 874.

Identification, cloning and characterization of R2R3-MYB gene family in canola (Brassica napus L.) identify a novel member modulating ROS accumulation and hypersensitive-like cell death

The R2R3-MYB proteins comprise one of the largest families of transcription factors in plants. Although genome-wide analysis of this family has been carried out in some plant species, little is known about R2R3-MYB genes in canola (Brassica napus L.). In this study, we have identified 76 R2R3-MYB genes in the canola genome through mining of expressed sequence tags (ESTs). The cDNA sequences of 44 MYB genes were successfully cloned. The transcriptional activities of BnaMYB proteins encoded by these genes were assayed in yeast. The subcellular localizations of representative R2R3-MYB proteins were investigated through GFP fusion. Besides, the transcript abundance level analysis during abiotic conditions and ABA treatment identified a group of R2R3-MYB genes that responded to one or more treatments. Furthermore, we identified a previously functionally unknown MYB gene-BnaMYB78, which modulates reactive oxygen species (ROS)-dependent cell death in Nicotiana benthamiana, through regulating the transcription of a few ROS- and defence-related genes. Taken together, this study has provided a solid foundation for understanding the roles and regulatory mechanism of canola R2R3-MYB genes.

Mitogen-activated protein kinase kinase kinase (MAPKKK) 4 from rapeseed (Brassica napus L.) is a novel member inducing ROS accumulation and cell death

MAPKKK is the largest family of MAPK cascade, which is known to play important roles in plant growth, development and immune responses. So far, only a few have been functionally characterized even in the model plant, Arabidopsis due to the potential functional redundancy of MAPKKK. We previously identified and cloned a few MAPKKK family genes from rapeseed. In this study, BnaMAPKKK4 was characterized as a member in eliciting accumulation of reactive oxygen species (ROS) and hypersensitive response (HR)-like cell death. This is accompanied with accumulation of malondialdehyde (MDA), anthocyanin as well as nuclear DNA fragmentation. The transcript abundance of a series of ROS accumulation, cell death, and defense response related genes were up-regulated by the expression of MAPKKK4. Further investigation identified BnaMAPKKK4 elicited ROS through the downstream MPK3. These results indicate that BnaMAPKKK4 and its downstream components function in the ROS-induced cell death.

Rapeseed calcineurin B-like protein CBL4, interacting with CBL-interacting protein kinase CIPK24, modulates salt tolerance in plants

Calcium is a ubiquitous intracellular secondary messenger in eukaryotes. Upon stress challenge, cytosolic Ca(2+) fluctuation could be sensed and bound by calcineurin B-like proteins (CBLs), which further regulate a group of Ser/Thr protein kinases called CBL-interacting protein kinases (CIPKs) to relay the signal and induce cellular responses. Although the CBL-CIPK network has been demonstrated to play crucial roles in plant development and responses to various environmental stresses in Arabidopsis, little is known about their function in rapeseed. In the present study, we characterized CBL4 gene from rapeseed. We found that CBL4 is localized at the plasma membrane and it interacted with CIPK24 in both yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. Unlike the orthologs in Arabidopsis, rapeseed CIPK24 did not interact with CBL10. Furthermore, expression of rapeseed CBL4 rescued the salt-sensitive phenotype of sos3-1 mutant and overexpression of rapeseed CBL4 in Arabidopsis showed enhanced tolerance of salt stress than wild-type. Overall, the results clarified the function of CBL4 in rapeseed.

Identification of a novel HLA-B*40 allele, HLA-B*40:229, in a Chinese individual

The novel HLA-B*40:229 allele shows one nucleotide difference from B*40:02:01 in exon 2 at nucleotide position 97 (C → T).

Impact of adherence to GOLD guidelines on 6-minute walk distance, MRC dyspnea scale score, lung function decline, quality of life, and quality-adjusted life years in a Shanghai suburb

We performed a 1-year cluster-randomized field trial to assess the effect of standardized management of chronic obstructive pulmonary disease (COPD) on lung function and quality of life (QOL) measures in patients in China. We used the Global Initiative for Chronic Obstructive Lung Disease (GOLD) treatment guidelines and assessed indexes including pulmonary function, QOL, quality-adjusted life years (QALY), Medical Research Council (MRC) dyspnea scale, 6-min walk distance (6-MWD), number of emergency visits, and frequency of hospitalization. Of a total of 711 patients with chronic cough and asthma, 132 were diagnosed as having COPD and 102 participated in this study [intervention group (N = 47); control group (N = 55)]. We found that adherence to GOLD guidelines had a perceivable impact on 6-MWD, MRC dyspnea scale score, and QOL. The average QALY increased by 1.42/person/year in the intervention group, but declined by 0.95/person/year in the control group. We conclude that standardized management improves disease severity, QOL, and QALY in COPD patients when treatment protocols adhere to GOLD guidelines.

A novel mutation links to von Hippel-Lindau syndrome in a Chinese family with hemangioblastoma

Hemangioblastoma of the central nervous system occurs as sporadic tumors or as a part of von Hippel-Lindau (VHL) disease, an autosomal dominant hereditary tumor syndrome caused by a germline mutation in the VHL tumor suppressor gene. We screened a Chinese family with VHL for mutations in the VHL gene and evaluated a genetic test for diagnosing VHL disease and clinical screening of family members. DNA extracted from the peripheral blood of all live members and from tissue of deceased family members with VHL disease was amplified by polymerase chain reaction to 3 VHL gene exons. Mutations in the amplification products were compared against the Human Gene Mutation Database. The involvement of multiple organs among the kindred with VHL disease was confirmed by medical history and radiography. Of the 12 members of the 4-generation family, 5 were diagnosed with VHL disease. Patient age at the initial diagnosis was 26-36 years (mean = 31 years). The mean time was 15 (11-19 months) from symptom appearance to the first patient visit to the hospital. Sequence analysis revealed that the frameshift mutation 327del C (p.Gly39Alafs*26) in exon 1 affected all family members, but not the healthy individuals or 16 unrelated controls. Members without gene mutation showed no clinical manifestation of VHL disease. We detected a conserved novel frameshift mutation in the VHL gene of the family members that contributes to VHL. DNA analysis of VHL is advantageous for VHL diagnosis. We developed a quick and reliable method for VHL diagnosis.

Identification of a novel HLA-A*24 variant allele, A*24:02:60

HLA-A*24:02:60 allele differs from A*24:02:01:01 by one nucleotide substitution at nt 564 from C to T.

Identification and characterization of plant-specific NAC gene family in canola (Brassica napus L.) reveal novel members involved in cell death

NAC transcription factors are plant-specific and play important roles in plant development processes, response to biotic and abiotic cues and hormone signaling. However, to date, little is known about the NAC genes in canola (or oilseed rape, Brassica napus L.). In this study, a total of 60 NAC genes were identified from canola through a systematical analysis and mining of expressed sequence tags. Among these, the cDNA sequences of 41 NAC genes were successfully cloned. The translated protein sequences of canola NAC genes with the NAC genes from representative species were phylogenetically clustered into three major groups and multiple subgroups. The transcriptional activities of these BnaNAC proteins were assayed in yeast. In addition, by quantitative real-time RT-PCR, we further observed that some of these BnaNACs were regulated by different hormone stimuli or abiotic stresses. Interestingly, we successfully identified two novel BnaNACs, BnaNAC19 and BnaNAC82, which could elicit hypersensitive response-like cell death when expressed in Nicotiana benthamiana leaves, which was mediated by accumulation of reactive oxygen species. Overall, our work has laid a solid foundation for further characterization of this important NAC gene family in canola.

Identification of a novel HLA-B*40 allele, HLA-B*40:210, in a Chinese individual

The newly detected HLA-B*40:210 allele has two nucleotide changes in exon 2 compared to B*40:49 allele.

Canola (Brassica napus L.) NAC103 transcription factor gene is a novel player inducing reactive oxygen species accumulation and cell death in plants

NAC transcription factors are plant-specific and play important roles in many processes including plant development, response to biotic and abiotic stresses and hormone signaling. So far, only a few NAC genes have been identified to mediate cell death. In this study, we identified a novel NAC gene from canola (Brassica napus L.), BnaNAC103 which induces reactive oxygen species (ROS) accumulation and cell death in Nicotianabenthamiana leaves. We found that BnaNAC103 responded to multiple signalings, including cold, salicylic acid (SA) and a fungal pathogen Sclerotinia sclerotiorum. BnaNAC103 is located in the nucleus. Expression of full-length BnaNAC103, but not either the N-terminal NAC domain or C-terminal regulatory domain, was identified to induce hypersensitive response (HR)-like cell death when expressed in N. benthamiana. The cell death triggered by BnaNAC103 is preceded by accumulation of ROS, with diaminobenzidine (DAB) staining supporting this. Moreover, quantification of ion leakage and malondialdehyde (MDA) of leaf discs indicates significant cell membrane breakage and lipid peroxidation induced by BnaNAC103 expression. Taken together, our work has identified a novel NAC transcription factor gene modulating ROS level and cell death in plants.

A new human leukocyte antigen class I allele: HLA-A*11:125

HLA-A*11:125 allele differs from A*11:01:01 by one nucleotide substitution at nt 140 from T to C.

Effects of alfalfa meal on growth performance and gastrointestinal tract development of growing ducks

A study was conducted to evaluate effects of alfalfa meal on growth performance and gastrointestinal tract development of growing layer ducks to provide evidence for application of alfalfa meal in the duck industry. Two hundred and fifty-six healthy Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a connecting water area. The results showed: i) Growing ducks fed alfalfa meal diet were not significantly different in average daily gain, feed intake and gain-to-feed ratio from those fed no alfalfa diet (p>0.05). ii) Alfalfa meal increased the ratio crop, gizzard to live weight, caecum to live weight, the caecum index of growing ducks (p<0.05). iii) Villus height in duodenum and jejunum of growing ducks increased significantly with the increase of alfalfa meal levels (p<0.05). Crypt depth in duodenum and jejunum of growing ducks decreased significantly with the increase of alfalfa meal levels (p<0.05). This experiment showed that feeding of alfalfa meal to growing layer ducks could improve gastrointestinal tract growth and small intestinal morphology without effect on performance. This experiment provides evidence that alfalfa meal is a very valuable feedstuff for growing layer ducks.

Identification and functional analysis of mitogen-activated protein kinase kinase kinase (MAPKKK) genes in canola (Brassica napus L.)

Mitogen-activated protein kinase (MAPK) signalling cascades, consisting of three types of reversibly phosphorylated kinases (MAPKKK, MAPKK, and MAPK), are involved in important processes including plant immunity and hormone responses. The MAPKKKs comprise the largest family in the MAPK cascades, yet only a few of these genes have been associated with physiological functions, even in the model plant Arabidopsis thaliana. Canola (Brassica napus L.) is one of the most important oilseed crops in China and worldwide. To explore MAPKKK functions in biotic and abiotic stress responses in canola, 66 MAPKKK genes were identified and 28 of them were cloned. Phylogenetic analysis of these canola MAPKKKs with homologous genes from representative species classified them into three groups (A-C), comprising four MAPKKKs, seven ZIKs, and 17 Raf genes. A further 15 interaction pairs between these MAPKKKs and the downstream BnaMKKs were identified through a yeast two-hybrid assay. The interactions were further validated through bimolecular fluorescence complementation (BiFC) analysis. In addition, by quantitative real-time reverse transcription-PCR, it was further observed that some of these BnaMAPKKK genes were regulated by different hormone stimuli, abiotic stresses, or fungal pathogen treatments. Interestingly, two novel BnaMAPKKK genes, BnaMAPKKK18 and BnaMAPKKK19, which could elicit hypersensitive response (HR)-like cell death when transiently expressed in Nicotiana benthamiana leaves, were successfully identified. Moreover, it was found that BnaMAPKKK19 probably mediated cell death through BnaMKK9. Overall, the present work has laid the foundation for further characterization of this important MAPKKK gene family in canola.

Identification, expression and interaction analyses of calcium-dependent protein kinase (CPK) genes in canola (Brassica napus L.)

BACKGROUND

Canola (Brassica napus L.) is one of the most important oil-producing crops in China and worldwide. The yield and quality of canola is frequently threatened by environmental stresses including drought, cold and high salinity. Calcium is a well-known ubiquitous intracellular secondary messenger in plants. Calcium-dependent protein kinases (CPKs) are Ser/Thr protein kinases found only in plants and some protozoans. CPKs are Ca2+ sensors that have both Ca2+ sensing function and kinase activity within a single protein and play crucial roles in plant development and responses to various environmental stresses.

RESULTS

In this study, we mined the available expressed sequence tags (ESTs) of B. napus and identified a total of 25 CPK genes, among which cDNA sequences of 23 genes were successfully cloned from a double haploid cultivar of canola. Phylogenetic analysis demonstrated that they could be clustered into four subgroups. The subcellular localization of five selected BnaCPKs was determined using green fluorescence protein (GFP) as the reporter. Furthermore, the expression levels of 21 BnaCPK genes in response to salt, drought, cold, heat, abscisic acid (ABA), low potassium (LK) and oxidative stress were studied by quantitative RT-PCR and were found to respond to multiple stimuli, suggesting that canola CPKs may be convergence points of different signaling pathways. We also identified and cloned five and eight Clade A basic leucine zipper (bZIP) and protein phosphatase type 2C (PP2C) genes from canola and, using yeast two-hybrid and bimolecular fluorescence complementation (BiFC), determined the interaction between individual BnaCPKs and BnabZIPs or BnaPP2Cs (Clade A). We identified novel, interesting interaction partners for some of the BnaCPK proteins.

CONCLUSION

We present the sequences and characterization of CPK gene family members in canola for the first time. This work provides a foundation for further crop improvement and improved understanding of signal transduction in plants.