Mitochondrial retrograde regulation tuning fork in nuclear genes expressions of higher plants

In plant cells, there are three organelles： the nucleus, chloroplast, and mitochondria that store genetic information. The nucleus possesses the majority of genetic information and controls most aspects of organelles gene expression, growth, and development. In return, organelles also send signals back to regulate nuclear gene expression, a process defmed as retrograde regulation. The best studies of organelles to nucleus retrograde regulation exist in plant chloroplast-to-nuclear regulation and yeast mitochondria-to-nuclear regulation. In this review, we summarize the recent understanding of mitochondrial retrograde regulation in higher plant, which involves multiple potential signaling pathway in relation to cytoplasmic male-sterility, biotic stress, and abiotic stress. With respect to mitochondrial retrograde regulation signal pathways involved in cytoplasmic male-sterility, we consider that nuclear transcriptional factor genes are the targeted genes regulated by mitochondria to determine the abnormal reproductive development, and the MAPK signaling pathway may be involved in this regulation in Brassica juncea. When plants suffer biotic and abiotic stress, plant ceils will initiate cell death or other events directed toward recovering from stress. During this process, we propose that mitochondria may determine how plant cell responds to a given stress through retrograde regulation. Meanwhile, several transducer molecules have also been discussed here. In particular, the Paepe research group reported that leaf mitochondrial modulated whole cell redox homeostasis, set antioxidant capacity, and determined stress resistance through altered signaling and diurnal regulation, which is an indication of plant mitochondria with more active function than ever.

Identification of MAM1s in Regulation of 3C Glucosinolates Accumulation in Allopolyploid Brassica juncea

Allopolyploid Brassica juncea is particularly enriched in sinigrin,a kind of 3C aliphatic glucosinolates(GSLs),giving rise to characteristic taste after picking.However,the molecular mechanism underlying 3C aliphatic GSLs biosynthesis in this species remains unknown.In this study,we genome-widely identified GSLs metabolic genes,indicating different evolutionary rate of GSLs metabolic genes between subgenomes of B.juncea.Eight methythioalkylmalate synthase(MAMs)homologs were identified from B.juncea,in which six MAM1s were located in chloroplast and the other two were not detected with any expression.Furthermore,BjMAM1-4,BjMAM1-5,and BjMAM1-6 displayed higher expression levels in leaves than other tissues.Silenced expression analysis revealed that BjMAM1-4 and BjMAM1-6 function in 3C and 4C aliphatic GSLs accumulation.The specificity of the substrate selection for the second cycle reaction is much lower than that of the first cycle,suggesting these genes may preferentially catalyze 3C aliphatic GSLs biosynthesis.Our study provides insights into the molecular mechanism underlying the accumulation of 3C aliphatic GSLs,thereby facilitating the manipulation of aliphatic GSLs content in B.juncea.

Eukaryotic Translation Initiation Factors Shape RNA Viruses Resistance in Plants

Viruses are representative of a global threat to agricultural production. Genetic resistance is the preferred strategy for the control of viral infection and against loss of crop yield. Viral protein synthesis requires host cellular factors for translating their viral RNAs, and for regulating their replication and cell to cell systemic movement. Therefore, the viruses are dependent on cellular translation factors. Mutations in the gene encoding eIF4E and eIF4G or their isoforms, eIFiso4 E, eIFiso4 G and eIF2Bβ have been mapped as a source of plant potyvirus while other genus of plant virus recessive resistance genes in many species are originated from these loci. Some of other plant translation factors, such as eIF3,eIF4 A-like helicases, eEF1A and eEF1B, which are required in interacting with viral RNAs and regulating various aspects of the infection cycle,have also been identified. Here, we summarized the mechanisms utilized by RNA viruses of eukaryotic plants and the essential roles of e IFs in virus infection. Moreover, we discussed the potential of e IFs as a target gene in the development of genetic resistance to viruses for crop improvement. This review highlighted newly revealed examples of abnormal translational strategies and provided insights into natural host resistance mechanisms that have been linked to 3 cap-independent translational enhancer activity.

Electric-field-induced in-plane effective 90°magnetization rotation in Co2FeAl/PMN-PT structure

The in-plane effective 90°magnetization rotation of Co_(2) FeAl thin film grown on PMN-PT substrate induced by the electric field is investigated at room temperature.The magnetic hysteresis loops under different positive and negative electric fields are obtained,which reveals remanent magnetization can be mediated by the electric field.Moreover,under positive electric fields,the obvious 90°magnetization rotation can be observed,while remanent magnetization is nearly unchanged under negative electric fields.The result is consistent with the electric field dependence of effective magnetic field,which can be attributed to the piezostrain effect in Co_(2) FeAl/PMN-PT structure.In addition,the piezostrain-mediated 90°magnetization rotation can be demonstrated by the result of resonance field changing with electric field in the measurement of ferromagnetic resonance,which is promising for the design of future multiferroic devices.

PRKCDBP Methylation is a Potential and Promising Candidate Biomarker for Non-small Cell Lung Cancer

Background and objectives:The occurrence and development of lung cancer are closely linked to epigenetic modification.Abnormal DNA methylation in the CpG island region of genes has been found in many cancers.Protein kinase C delta binding protein(PRKCDBP) is a potential tumor suppressor and its epigenetic changes are found in many human malignancies.This study investigated the possibility of PRKCDBP methylation as a potential biomarker for non-small cell lung cancer(NSCLC).Methods:We measured the methylation levels of PRKCDBP in the three groups of NSCLC tissues.Promoter activity was measured by the dual luciferase assay,with S’-aza-deoxycytidine to examine the effect of demethylation on the expression level of PRKCDBP.Results:The methylation levels of PRKCDBP in tumor tissues and 3 cm para-tumor were higher than those of distant(>10 cm)non-tumor tissues.Receiver operating characteristic(ROC) curve analysis between tumor tissues and distant non-tumor tissues showed that the area under the line(AUC) was 0.717.Dual luciferase experiment confirmed that the promoter region was able to promote gene expression.Meanwhile,in vitro methylation of the fragment(PRKCDBP;e) could significantly reduce the promoter activity of the fragment.Demethylation of 5’-aza-deoxycytidine in lung cancer cell lines A549 and H1299 showed a significant up-regulation of PRKCDBP mRNA levels.Conclusion:PRKCDBP methylation is a potential and promising candidate biomarker for non-small cell lung cancer.

啤酒酵母细胞壁环境压力应答机制研究进展

酵母细胞壁在细胞形态学的建立和维持中起重要作用,有助于细胞抵御环境变化。细胞壁主要由β-葡聚糖、甘露糖蛋白和几丁质组成,其组成和结构会由于压力胁迫发生动态重构。同时为了适应环境压力变化,啤酒酵母细胞壁在长期驯化过程中表现出相关压力应答机制。文中介绍了啤酒酵母细胞壁组成与结构,并综述了细胞壁重构与信号通路调控的分子机制。

Identification of Flowering Regulatory Genes in Allopolyploid Brassica juncea

Brassica juncea is an allopolyploid originating from the interspecific hybridization between Brassica rapa and Brassica nigra, which is of multiple usage as a vegetable, oilseed and condiment worldwide. Both vernalization and non-vernalization under long-day photoperiod can promote floral transition in B. juncea suggesting merged flowering pathways of its ancestors and better environmental adaptability. We identified genomewide flowering regulatory genes in B. juncea, which include 84 and 79 genes from A and B sub-genomes, respectively. Ka/Ks analysis revealed a purification effect on both photoperiod and vernalization flowering regulation pathways during evolution. Expression profile of those genes during long-day and vernalization treatments suggested Bju ACO4, Bju AFT1, Bju BFT4, Bju ASOC1 and Bju ASOC4 may be the major functional copies of B. juncea flowering regulation. Further functional studies about Bju COs showed three days delayed flowering time in Bju ACO4 or Bju BCO3 silenced plants. Increased transcription of all BjuFLCs in Bju ACO4 or Bju BCO3 silenced plants suggested interactions between photoperiod and vernalization pathways governing flowering time. Our findings provided flowering regulating networks in allopolyploid B. juncea.

Tomato leaf curl New Delhi virus:an emerging plant begomovirus threatening cucurbit production

Tomato leaf curl New Delhi virus(ToLCNDV),a bipartite begomovirus,was first reported to infect tomato and has recently spread rapidly as an emerging disease to Cucurbitaceae crops.To date,the virus has been reported to infect more than 11 cucurbit crops,in 16 countries and regions,causing severe yield losses.In autumn 2022,ToLCNDV was first isolated from cucurbit plants in Southeastern coastal areas of China.Phylogenetic analysis established that these isolates belong to the Asian ToLCNDV clade,and shared high nucleotide identity and closest genetic relationship with the DNA-A sequence from the Chinese tomato-infecting ToLCNDV isolate(Accession no.OP356207)and the tomato New Delhi ToLCNDV-Severe isolate(Accession no.HM159454).In this review,we summarize the occurrence and distribution,host range,detection and diagnosis,control strategies,and genetic resistance of ToLCNDV in the Cucurbitaceae.We then summarize pathways that could be undertaken to improve our understanding of this emerging disease,with the objective to develop ToLCNDV-resistant cucurbit cultivars.