Leaf senescence is a highly coordinated, complicated process involving the integration of numerous internal and environmental signals. Salicylic acid (SA) and reactive oxygen species (ROS) are two well-defined inducers of leaf senescence whose contents progressively and interdependently increase during leaf senescence via an unknown mechanism. Here, we characterized the transcription factor WRKY75 as a positive regulator of leaf senescence in Knockdown or knockout of delayed age-dependent leaf senescence, while overexpression of accelerated this process. transcription is induced by age, SA, HO, and multiple plant hormones. Meanwhile, WRKY75 promotes SA production by inducing the transcription of () and suppresses HO scavenging, partly by repressing the transcription of (). Genetic analysis revealed that the mutation of or an increase in catalase activity rescued the precocious leaf senescence phenotype evoked by overexpression. Based on these results, we propose a tripartite amplification loop model in which WRKY75, SA, and ROS undergo a gradual but self-sustained rise driven by three interlinking positive feedback loops. This tripartite amplification loop provides a molecular framework connecting upstream signals, such as age and plant hormones, to the downstream regulatory network executed by SA- and HO-responsive transcription factors during leaf senescence.

Ethylene has been regarded as a stress hormone to regulate myriad stress responses. Salinity stress is one of the most serious abiotic stresses limiting plant growth and development. But how ethylene signaling is involved in plant response to salt stress is poorly understood. Here we showed that Arabidopsis plants pretreated with ethylene exhibited enhanced tolerance to salt stress. Gain- and loss-of-function studies demonstrated that EIN3 (ETHYLENE INSENSITIVE 3) and EIL1 (EIN3-LIKE 1), two ethylene-activated transcription factors, are necessary and sufficient for the enhanced salt tolerance. High salinity induced the accumulation of EIN3/EIL1 proteins by promoting the proteasomal degradation of two EIN3/EIL1-targeting F-box proteins, EBF1 and EBF2, in an EIN2-independent manner. Whole-genome transcriptome analysis identified a list of SIED (Salt-Induced and EIN3/EIL1-Dependent) genes that participate in salt stress responses, including several genes encoding reactive oxygen species (ROS) scavengers. We performed a genetic screen for ein3 eil1-like salt-hypersensitive mutants and identified 5 EIN3 direct target genes including a previously unknown gene, SIED1 (At5g22270), which encodes a 93-amino acid polypeptide involved in ROS dismissal. We also found that activation of EIN3 increased peroxidase (POD) activity through the direct transcriptional regulation of PODs expression. Accordingly, ethylene pretreatment or EIN3 activation was able to preclude excess ROS accumulation and increased tolerance to salt stress. Taken together, our study provides new insights into the molecular action of ethylene signaling to enhance plant salt tolerance, and elucidates the transcriptional network of EIN3 in salt stress response.

The zero-profile, stand-alone Fidji cervical cage for ACDF is an effective, reliable, and safe alternate to the conventional method for the treatment of cervical DDD. However, there is no definitive evidence that Fidji cervical cage has better intermediate-term outcomes than the stand-alone cages with a titanium plate for ACDF.

BackgroundIn cellulolytic fungi, induction and repression mechanisms synchronously regulate the synthesis of cellulolytic enzymes for accurate responses to carbon sources in the environment. Many proteins, particularly transcription regulatory factors involved in these processes, were identified and genetically engineered in Penicillium oxalicum and other cellulolytic fungi. Despite such great efforts, its effect of modifying a single target to improve the production of cellulase is highly limited.ResultsIn this study, we developed a systematic strategy for the genetic engineering of P. oxalicum to enhance cellulase yields, by enhancing induction (by blocking intracellular inducer hydrolysis and increasing the activator level) and relieving the repression. We obtained a trigenic recombinant strain named ‘RE-10’ by deleting bgl2 and creA, along with over-expressing the gene clrB. The cellulolytic ability of RE-10 was significantly improved; the filter paper activity and extracellular protein concentration increased by up to over 20- and 10-fold, respectively, higher than those of the wild-type (WT) strain 114-2 both on pure cellulose and complex wheat bran media. Most strikingly, the cellulolytic ability of RE-10 was comparable with that of the industrial P. oxalicum strain JU-A10-T obtained by random mutagenesis. Comparative proteomics analysis provided further insights into the differential secretomes between RE-10 and WT strains. In particular, the enzymes and accessory proteins involved in lignocellulose degradation were elevated specifically and dramatically in the recombinant, thereby confirming the importance of them in biomass deconstruction and implying a possible co-regulatory mechanism.ConclusionsWe established a novel route to substantially improve cellulolytic enzyme production up to the industrial level in P. oxalicum by combinational manipulation of three key genes to amplify the induction along with derepression, representing a milestone in strain engineering of filamentous fungi. Given the conservation in the mode of cellulose expression regulation among filamentous fungi, this strategy could be compatible with other cellulase-producing fungi.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-015-0253-8) contains supplementary material, which is available to authorized users.

Between 2001 and 2005, 43 patients (average age 54.2, range 36-68 years) with recurrent lumbar disc herniation underwent reoperation with the transforaminal lumbar interbody fusion (TLIF) technique at our unit. All cases were followed up for 24-72 months (mean 45 months) and graded using the Japanese Orthopaedic Association (JOA) score system pre-and post-operation and during the follow-up period. The leg pain of all patients was relieved significantly within one month postoperatively. The mean JOA score was improved from 9.3 before surgery to 25.0 at the final follow-up visit (P<0.0001). The average recovery rate was 86.0% (range 52-100%). General clinical outcome was excellent in 23 (53.5%) patients, good in 14 (32.6%) and fair in 6 (13.9%). The fusion rate was 100% two years postoperatively. Three patients (7%) had transient neurological deficits, which resolved completely within 3 months. There were no major complications. We, therefore, believe the TLIF technique to be an effective procedure with satisfactory clinical results for the treatment of recurrent lumbar disc herniation.Résumé Entre 2001 et 2005, 43 patients (âge moyen 54,2 ans entre 36 à 68 ans) ont bénéficié d'une réintervention chirurgicale avec arthrodèse inter corporéale par technique transforaminale pour récidive de hernie discale lombaire. Tous ces patients ont été suivis en moyenne pendant 45 mois et évalués selon le score de la JOA en pré et post opératoire. Les douleurs des membres de tous ces patients ont été nettement améliorées dans le premier mois post opératoire. Le score de la JOA a été également améliorée de 9,3 avant l'intervention à 25 lors de la dernière revue de ces malades (P<0,0001). Le taux moyen de récupération a été de 86% (52 à 100%). L'évolution clinique générale a été excellente chez 23 patients (53,5%), bonne chez 14 patients (32,6%) et médiocre chez 6 patients (13,9%). Le taux de fusion a été de 100% en post opératoire. 3 patients (7%) ont eu des troubles neurologiques transitoires qui ont complète-ment régressé dans les trois mois. Il n'y a pas eu de complications majeures. L'étude technique TLIF est une technique efficace qui nous donne satisfaction dans le traitement des récidives de hernies discales lombaires.

The National Genomics Data Center (NGDC) provides a suite of database resources to support worldwide research activities in both academia and industry. With the rapid advancements in higher-throughput and lower-cost sequencing technologies and accordingly the huge volume of multi-omics data generated at exponential scales and rates, NGDC is continually expanding, updating and enriching its core database resources through big data integration and value-added curation. In the past year, efforts for update have been mainly devoted to BioProject, BioSample, GSA, GWH, GVM, NONCODE, LncBook, EWAS Atlas and IC4R. Newly released resources include three human genome databases (PGG.SNV, PGG.Han and CGVD), eLMSG, EWAS Data Hub, GWAS Atlas, iSheep and PADS Arsenal. In addition, four web services, namely, eGPS Cloud, BIG Search, BIG Submission and BIG SSO, have been significantly improved and enhanced. All of these resources along with their services are publicly accessible at https://bigd.big.ac.cn.

Long-term strain improvements through repeated mutagenesis and screening have generated a hyper-producer of cellulases and hemicellulases from Penicillium decumbens 114 which was isolated 30 years ago. Here, the genome of the hyper-producer P. decumbens JU-A10-T was sequenced and compared with that of the wild-type strain 114-2. Further, the transcriptomes and secretomes were compared between the strains. Selective hyper-production of cellulases and hemicellulases but not all the secreted proteins was observed in the mutant, making it a more specific producer of lignocellulolytic enzymes. Functional analysis identified that changes in several transcriptional regulatory elements played crucial roles in the cellulase hyper-producing characteristics of the mutant. Additionally, the mutant showed enhanced supply of amino acids and decreased synthesis of secondary metabolites compared with the wild-type. The results clearly point out that we can target gene regulators and promoters with minimal alterations of the genetic content but maximal effects in genetic engineering.

BackgroundLignocellulolytic enzymes are the main enzymes to saccharify lignocellulose from renewable plant biomass in the bio-based economy. The production of these enzymes is transcriptionally regulated by multiple transcription factors. We previously engineered Penicillium oxalicum for improved cellulase production via manipulation of three genes in the cellulase expression regulatory network. However, the potential of combinational engineering of multiple regulators and their targets at protein abundance and activity levels has not been fully explored.ResultsHere, we verified that a point mutation XlnRA871V in transcription factor XlnR enhanced the expression of lignocellulolytic enzymes, particularly hemicellulases, in P. oxalicum. Then, overexpression of XlnRA871V with a constitutive PDE_02864 promoter was combined with the overexpression of cellulase transcriptional activator ClrB and deletion of carbon catabolite repressor CreA. The resulted strain RE-7 showed 8.9- and 51.5-fold increased production of cellulase and xylanase relative to the starting strain M12, respectively. Further overexpression of two major cellulase genes cbh1-2 and eg1 enabled an additional 13.0% improvement of cellulase production. In addition, XlnRA871V led to decreased production of β-glucosidase and amylase, which could be attributed to the reduced transcription of corresponding enzyme-encoding genes.ConclusionsThe results illustrated that combinational manipulation of the involved transcription factors and their target genes was a viable strategy for efficient production of lignocellulolytic enzymes in filamentous fungi. The striking negative effect of XlnRA871V mutation on amylase production was also highlighted.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-017-0783-3) contains supplementary material, which is available to authorized users.