Pathways of pathogenicity: The transcriptional stages of germination in the fatal fungal pathogen Rhizopus delemar

AbstractRhizopus delemar is an invasive fungal pathogen, responsible for the frequently fatal disease mucormycosis. Germination, a crucial mechanism by which spores of Rhizopus delemar infect and cause disease, is a key developmental process that transforms the dormant spore state into a vegetative one. Understanding the molecular mechanisms which underpin this transformation may be key to controlling mucormycosis, however the regulation of germination remains poorly understood. This study describes the phenotypic and transcriptional changes which take place over the course of germination. This process is characterised by four distinct stages: dormancy, isotropic swelling, germ tube emergence and hyphal growth. Dormant spores are shown to be transcriptionally unique, expressing a subset of transcripts absent in later developmental stages. A large shift in the expression profile is prompted by the initiation of germination, with genes involved in respiration, chitin, cytoskeleton and actin regulation appearing to be important for this transition. A period of transcriptional consistency can be seen throughout isotropic swelling, before the transcriptional landscape shifts again at the onset of hyphal growth. This study provides a greater understanding of the regulation of germination and highlights processes involved in transforming Rhizopus delemar from a single to a multicellular organism.ImportanceGermination is key to the growth of many organisms, including fungal spores. Mucormycete spores exist abundantly within the environment and germinate to form hyphae. These spores are capable of infecting immunocompromised individuals, causing the disease mucormycosis Germination from spore to hyphae within patients leads to angioinvasion, tissue necrosis and often fatal infections. This study advances our understanding of how spore germination occurs in the mucormycetes, identifying processes we may be able to inhibit to help prevent or treat mucormycosis.

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Pathways of Pathogenicity: Transcriptional Stages of Germination in the Fatal Fungal PathogenRhizopus delemar

mSphere ◽

10.1128/msphere.00403-18 ◽

2018 ◽

Vol 3 (5) ◽

Cited By ~ 5

Author(s):

Poppy C. S. Sephton-Clark ◽

Jose F. Muñoz ◽

Elizabeth R. Ballou ◽

Christina A. Cuomo ◽

Kerstin Voelz

Keyword(s):

Molecular Mechanisms ◽

Developmental Stages ◽

Developmental Process ◽

Fungal Spores ◽

Hyphal Growth ◽

Large Shift ◽

Rhizopus Delemar ◽

Content Type ◽

Transcriptional Changes ◽

Dormant Spore

ABSTRACTRhizopus delemaris an invasive fungal pathogen responsible for the frequently fatal disease mucormycosis. Germination, a crucial mechanism by which infectious spores ofRhizopus delemarcause disease, is a key developmental process that transforms the dormant spore state into a vegetative one. The molecular mechanisms that underpin this transformation may be key to controlling mucormycosis; however, the regulation of germination remains poorly understood. This study describes the phenotypic and transcriptional changes that take place over the course of germination. This process is characterized by four distinct stages: dormancy, isotropic swelling, germ tube emergence, and hyphal growth. Dormant spores are shown to be transcriptionally unique, expressing a subset of transcripts absent in later developmental stages. A large shift in the expression profile is prompted by the initiation of germination, with genes involved in respiration, chitin, cytoskeleton, and actin regulation appearing to be important for this transition. A period of transcriptional consistency can be seen throughout isotropic swelling, before the transcriptional landscape shifts again at the onset of hyphal growth. This study provides a greater understanding of the regulation of germination and highlights processes involved in transformingRhizopus delemarfrom a single-cellular to multicellular organism.IMPORTANCEGermination is key to the growth of many organisms, including fungal spores. Mucormycete spores exist abundantly within the environment and germinate to form hyphae. These spores are capable of infecting immunocompromised individuals, causing the disease mucormycosis. Germination from spore to hyphae within patients leads to angioinvasion, tissue necrosis, and often fatal infections. This study advances our understanding of how spore germination occurs in the mucormycetes, identifying processes we may be able to inhibit to help prevent or treat mucormycosis.

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Integrating transcriptome and metabolome reveals molecular networks involved in genetic and environmental variation in tobacco

DNA Research ◽

10.1093/dnares/dsaa006 ◽

2020 ◽

Vol 27 (2) ◽

Author(s):

Pingping Liu ◽

Jie Luo ◽

Qingxia Zheng ◽

Qiansi Chen ◽

Niu Zhai ◽

...

Keyword(s):

Regulatory Networks ◽

Molecular Mechanisms ◽

Developmental Stages ◽

De Novo ◽

Developmental Process ◽

Pearson Correlation ◽

Molecular Networks ◽

Environmental Perturbations ◽

Carotenoid Metabolism ◽

Gene Modules

Abstract Tobacco (Nicotiana tabacum) is one of the most widely cultivated commercial non-food crops with significant social and economic impacts. Here we profiled transcriptome and metabolome from 54 tobacco samples (2–3 replicates; n = 151 in total) collected from three varieties (i.e. genetic factor), three locations (i.e. environmental factor), and six developmental stages (i.e. developmental process). We identified 3,405 differentially expressed (DE) genes (DEGs) and 371 DE metabolites, respectively. We used quantitative real-time PCR to validate 20 DEGs, and confirmed 18/20 (90%) DEGs between three locations and 16/20 (80%) with the same trend across developmental stages. We then constructed nine co-expression gene modules and four co-expression metabolite modules , and defined seven de novo regulatory networks, including nicotine- and carotenoid-related regulatory networks. A novel two-way Pearson correlation approach was further proposed to integrate co-expression gene and metabolite modules to identify joint gene–metabolite relations. Finally, we further integrated DE and network results to prioritize genes by its functional importance and identified a top-ranked novel gene, LOC107773232, as a potential regulator involved in the carotenoid metabolism pathway. Thus, the results and systems-biology approaches provide a new avenue to understand the molecular mechanisms underlying complex genetic and environmental perturbations in tobacco.

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Comparative transcriptome analysis of hard and tender fruit spines of cucumber to identify genes involved in morphological development of fruit spines

10.21203/rs.3.rs-31353/v2 ◽

2020 ◽

Author(s):

Duo Lv ◽

Yao Yu ◽

Liang-Rong Xiong ◽

Gang Wang ◽

Jin-An Pang ◽

...

Keyword(s):

Transcription Factors ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Developmental Process ◽

Stage Iii ◽

Morphological Development ◽

Wild Type ◽

Polar Transport ◽

Cucumber Fruit ◽

Auxin Polar Transport

Abstract Background: The trichomes of cucumber fruits are also called spines. Cucumber has important commercial value, and its fruit spines represent a classical tissue with which to study the cell division and differentiation mode of multicellular trichomes. Although there have been many studies on the development of unicellular trichomes in model plants, the molecular mechanism of multicellular trichome formation remains elusive. In this study, we used a pair of cucumber materials defined as having hard (Ts, wild type) or tender (ts, mutant) spines in a previous study. The whole developmental process of fruit spines was continuously observed by microscopy and SEM. In an attempt to define the developmental stages of fruit spines, transcriptome profiles at different stages were determined to explore the molecular mechanisms underlying the process of spine development. Results: According to significant phenotypic differences, the developmental process of fruit spines was clearly defined as involving four stages. Comparison of transcriptome profiles showed that 803 and 722 genes were upregulated in the stalk (stage II and stage III) and base (stage IV) developmental stages of fruit spines, respectively. Functional analysis of differentially expressed genes (DEGs) showed that for all developmental stages of fruit spines, lipid metabolism, amino acid metabolism, and signal transduction were the most noticeable pathways. However, during the development of the stalk, genes related to auxin polar transport and HD-ZIP transcription factors were significantly upregulated. bHLH transcription factors and cytoskeleton-related genes were significantly upregulated during the development of the base. In addition, stage III was the key point for differentiating between the wild type and mutant. We detected 628 DEGs between the wild type and mutant at this stage. These DEGs are mainly involved in calcium signaling of the cytoskeleton and auxin polar transport, indicating that the main reason for the disorder of the fruit spine developmental pattern in the mutant was a change in cell polarity caused by blocked intercellular signal transmission.Conclusions: Our study defines in great detail the developmental stages of cucumber fruit spines. At the same time, transcriptome profiles are used to present the gene regulatory networks at different developmental stages of cucumber fruit spines. In addition, we analyzed transcriptomic data of a wild type and mutant to elucidate the biological pathways involving C-type lectin receptor-like kinase that regulate the development of fruit spines.

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Differential Regulation of Anthocyanins in Green and Purple Turnips Revealed by Combined De Novo Transcriptome and Metabolome Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms20184387 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4387 ◽

Cited By ~ 13

Author(s):

Hongmei Zhuang ◽

Qian Lou ◽

Huifang Liu ◽

Hongwei Han ◽

Qiang Wang ◽

...

Keyword(s):

Molecular Mechanisms ◽

Developmental Stages ◽

De Novo ◽

Skin Pigmentation ◽

Anthocyanin Content ◽

Anthocyanidin Synthase ◽

De Novo Transcriptome ◽

Metabolome Analysis ◽

Transcriptional Changes ◽

The Difference

Purple turnip Brassica rapa ssp. rapa is highly appreciated by consumers but the metabolites and molecular mechanisms underlying the root skin pigmentation remain open to study. Herein, we analyzed the anthocyanin composition in purple turnip (PT) and green turnip (GT) at five developmental stages. A total of 21 anthocyanins were detected and classified into the six major anthocynanin aglycones. Distinctly, PT contains 20 times higher levels of anthocyanins than GT, which explain the difference in the root skin pigmentation. We further sequenced the transcriptomes and analyzed the differentially expressed genes between the two turnips. We found that PT essentially diverts dihydroflavonols to the biosynthesis of anthocyanins over flavonols biosynthesis by strongly down-regulating one flavonol synthase gene, while strikingly up-regulating dihydroflavonol 4-reductase (DFR), anthocyanidin synthase and UDP-glucose: flavonoid-3-O-glucosyltransferase genes as compared to GT. Moreover, a nonsense mutation identified in the coding sequence of the DFR gene may lead to a nonfunctional protein, adding another hurdle to the accumulation of anthocyanin in GT. We also uncovered several key members of MYB, bHLH and WRKY families as the putative main drivers of transcriptional changes between the two turnips. Overall, this study provides new tools for modifying anthocyanin content and improving turnip nutritional quality.

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The diverse roles of cytokinins in regulating leaf development

Horticulture Research ◽

10.1038/s41438-021-00558-3 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Wenqi Wu ◽

Kang Du ◽

Xiangyang Kang ◽

Hairong Wei

Keyword(s):

Leaf Development ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Developmental Process ◽

Chlorophyll Synthesis ◽

Growth Potential ◽

Sugar Accumulation ◽

Developmental Processes ◽

Leaf Formation ◽

Underlying Mechanisms

AbstractLeaves provide energy for plants, and consequently for animals, through photosynthesis. Despite their important functions, plant leaf developmental processes and their underlying mechanisms have not been well characterized. Here, we provide a holistic description of leaf developmental processes that is centered on cytokinins and their signaling functions. Cytokinins maintain the growth potential (pluripotency) of shoot apical meristems, which provide stem cells for the generation of leaf primordia during the initial stage of leaf formation; cytokinins and auxins, as well as their interaction, determine the phyllotaxis pattern. The activities of cytokinins in various regions of the leaf, especially at the margins, collectively determine the final leaf morphology (e.g., simple or compound). The area of a leaf is generally determined by the number and size of the cells in the leaf. Cytokinins promote cell division and increase cell expansion during the proliferation and expansion stages of leaf cell development, respectively. During leaf senescence, cytokinins reduce sugar accumulation, increase chlorophyll synthesis, and prolong the leaf photosynthetic period. We also briefly describe the roles of other hormones, including auxin and ethylene, during the whole leaf developmental process. In this study, we review the regulatory roles of cytokinins in various leaf developmental stages, with a focus on cytokinin metabolism and signal transduction processes, in order to shed light on the molecular mechanisms underlying leaf development.

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Transcriptome Analysis Provides Insights into Grain Filling in Foxtail Millet (Setaria italica L.)

International Journal of Molecular Sciences ◽

10.3390/ijms21145031 ◽

2020 ◽

Vol 21 (14) ◽

pp. 5031

Author(s):

Tao Wang ◽

Hui Song ◽

Pengtao Li ◽

Yangyang Wei ◽

Nan Hu ◽

...

Keyword(s):

Molecular Mechanisms ◽

Developmental Stages ◽

Developmental Process ◽

Expression Patterns ◽

Foxtail Millet ◽

Grain Filling ◽

Polyamine Metabolism ◽

Transcriptional Dynamics ◽

Yield And Quality

Grain filling is an importantly developmental process which is associated with the yield and quality of foxtail millet (Setaria italic L.). However, the molecular mechanisms of grain filling are rarely reported in foxtail millet. In our study, RNA-seq was performed to investigate the transcriptional dynamics and identify the key genes involved in grain filling in foxtail millet at five different developmental stages. A total of 11,399 differentially expressed genes (DEGs), including 902 transcription factors (TFs), were identified. Certain important genes involved in grain filling were discovered through a function annotation and temporal expression patterns analysis. These genes included genes associated with starch biosynthesis, cell-wall invertases, hormone signal transduction, and polyamine metabolism pathways. The expression levels of seven randomly selected DEGs were validated by a quantitative real-time polymerase chain reaction (qRT-PCR). This study provides the first insight into the changes in the gene expression of grain filling at different developmental stages in foxtail millet. These results could help understand the complex molecular mechanisms of the panicle formation in foxtail millet and other cereal crops.

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Integrated transcriptomic and proteomic analysis reveals the complex molecular mechanisms underlying stone cell formation in Korla pear

Scientific Reports ◽

10.1038/s41598-021-87262-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Aisajan Mamat ◽

Kuerban Tusong ◽

Juan Xu ◽

Peng Yan ◽

Chuang Mei ◽

...

Keyword(s):

Cell Differentiation ◽

Proteomic Analysis ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Cell Formation ◽

Parenchyma Cell ◽

Lignin Biosynthesis ◽

Cell Content ◽

Stone Cell ◽

Fruit Samples

AbstractKorla pear (Pyrus sinkiangensis Yü) is a landrace selected from a hybrid pear species in the Xinjiang Autonomous Region in China. In recent years, pericarp roughening has been one of the major factors that adversely affects fruit quality. Compared with regular fruits, rough-skin fruits have a greater stone cell content. Stone cells compose sclerenchyma tissue that is formed by secondary thickening of parenchyma cell walls. In this work, we determined the main components of stone cells by isolating them from the pulp of rough-skin fruits at the ripening stage. Stone cell staining and apoptosis detection were then performed on fruit samples that were collected at three different developmental stages (20, 50 and 80 days after flowering (DAF)) representing the prime, late and stationary stages of stone cell differentiation, respectively. The same batches of samples were used for parallel transcriptomic and proteomic analysis to identify candidate genes and proteins that are related to SCW biogenesis in Korla pear fruits. The results showed that stone cells are mainly composed of cellulose (52%), hemicellulose (23%), lignin (20%) and a small amount of polysaccharides (3%). The periods of stone cell differentiation and cell apoptosis were synchronous and primarily occurred from 0 to 50 DAF. The stone cell components increased abundantly at 20 DAF but then decreased gradually. A total of 24,268 differentially expressed genes (DEGs) and 1011 differentially accumulated proteins (DAPs) were identified from the transcriptomic and proteomic data, respectively. We screened the DEGs and DAPs that were enriched in SCW-related pathways, including those associated with lignin biosynthesis (94 DEGs and 31 DAPs), cellulose and xylan biosynthesis (46 DEGs and 18 DAPs), S-adenosylmethionine (SAM) metabolic processes (10 DEGs and 3 DAPs), apoplastic ROS production (16 DEGs and 2 DAPs), and cell death (14 DEGs and 6 DAPs). Among the identified DEGs and DAPs, 63 significantly changed at both the transcript and protein levels during the experimental periods. In addition, the majority of these identified genes and proteins were expressed the most at the prime stage of stone cell differentiation, but their levels gradually decreased at the later stages.

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Integrative Modelling of Gene Expression and Digital Phenotypes to Describe Senescence in Wheat

Genes ◽

10.3390/genes12060909 ◽

2021 ◽

Vol 12 (6) ◽

pp. 909

Author(s):

Anyela Valentina Camargo Rodriguez

Keyword(s):

Gene Expression ◽

Regulatory Networks ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Computational Modelling ◽

Plant Morphology ◽

Reproductive Organs ◽

Biological Trait ◽

Cereal Grain ◽

Plant Level

Senescence is the final stage of leaf development and is critical for plants’ fitness as nutrient relocation from leaves to reproductive organs takes place. Although senescence is key in nutrient relocation and yield determination in cereal grain production, there is limited understanding of the genetic and molecular mechanisms that control it in major staple crops such as wheat. Senescence is a highly orchestrated continuum of interacting pathways throughout the lifecycle of a plant. Levels of gene expression, morphogenesis, and phenotypic development all play key roles. Yet, most studies focus on a short window immediately after anthesis. This approach clearly leaves out key components controlling the activation, development, and modulation of the senescence pathway before anthesis, as well as during the later developmental stages, during which grain development continues. Here, a computational multiscale modelling approach integrates multi-omics developmental data to attempt to simulate senescence at the molecular and plant level. To recreate the senescence process in wheat, core principles were borrowed from Arabidopsis Thaliana, a more widely researched plant model. The resulted model describes temporal gene regulatory networks and their effect on plant morphology leading to senescence. Digital phenotypes generated from images using a phenomics platform were used to capture the dynamics of plant development. This work provides the basis for the application of computational modelling to advance understanding of the complex biological trait senescence. This supports the development of a predictive framework enabling its prediction in changing or extreme environmental conditions, with a view to targeted selection for optimal lifecycle duration for improving resilience to climate change.

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Combining QTL Mapping and Gene Expression Analysis to Elucidate the Genetic Control of ‘Crumbly’ Fruit in Red Raspberry (Rubus idaeus L.)

Agronomy ◽

10.3390/agronomy11040794 ◽

2021 ◽

Vol 11 (4) ◽

pp. 794

Author(s):

Luca M. Scolari ◽

Robert D. Hancock ◽

Pete E. Hedley ◽

Jenny Morris ◽

Kay Smith ◽

...

Keyword(s):

Genetic Control ◽

Developmental Disorder ◽

Molecular Mechanisms ◽

Developmental Stages ◽

Microarray Experiment ◽

Rubus Idaeus ◽

Red Raspberry ◽

Genotype By Sequencing ◽

First Time ◽

Selection Of

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.

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Functional antagonism of chromatin modulators regulates epithelial-mesenchymal transition

Science Advances ◽

10.1126/sciadv.abd7974 ◽

2021 ◽

Vol 7 (9) ◽

pp. eabd7974

Author(s):

Michela Serresi ◽

Sonia Kertalli ◽

Lifei Li ◽

Matthias Jürgen Schmitt ◽

Yuliia Dramaretska ◽

...

Keyword(s):

Cancer Cells ◽

Transcriptional Control ◽

Molecular Mechanisms ◽

Developmental Process ◽

Epithelial Mesenchymal Transition ◽

Chromatin Remodelers ◽

Mesenchymal Transition ◽

Signature Genes ◽

Chromatin Regulators ◽

The Impact

Epithelial-mesenchymal transition (EMT) is a developmental process hijacked by cancer cells to modulate proliferation, migration, and stress response. Whereas kinase signaling is believed to be an EMT driver, the molecular mechanisms underlying epithelial-mesenchymal interconversion are incompletely understood. Here, we show that the impact of chromatin regulators on EMT interconversion is broader than that of kinases. By combining pharmacological modulation of EMT, synthetic genetic tracing, and CRISPR interference screens, we uncovered a minority of kinases and several chromatin remodelers, writers, and readers governing homeostatic EMT in lung cancer cells. Loss of ARID1A, DOT1L, BRD2, and ZMYND8 had nondeterministic and sometimes opposite consequences on epithelial-mesenchymal interconversion. Together with RNAPII and AP-1, these antagonistic gatekeepers control chromatin of active enhancers, including pan-cancer-EMT signature genes enabling supraclassification of anatomically diverse tumors. Thus, our data uncover general principles underlying transcriptional control of cancer cell plasticity and offer a platform to systematically explore chromatin regulators in tumor-state–specific therapy.

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