scholarly journals A galling insect activates plant reproductive programs during gall development

2018 ◽  
Author(s):  
Jack C. Schultz ◽  
Patrick P. Edger ◽  
Mélanie J.A. Body ◽  
Heidi M. Appel

AbstractSome insects can redirect plant development to form unique organs called galls, which provide these insects with unique, enhanced food and protection from enemies and the elements. Many galls resemble flowers or fruits, suggesting that elements of reproductive development may be involved. We tested this hypothesis using RNA sequencing (RNAseq) to quantify the transcriptional responses of wild grapevine (Vitis riparia Michx.) leaves to a galling parasite, phylloxera (Daktulosphaira vitifolia (Fitch 1855)). If development of reproductive structures is part of gall formation, we expected to find significantly elevated expression of genes involved in flower and/or fruit development in developing galls as opposed to ungalled leaves. We found that reproductive gene ontology (GO) categories were significantly enriched in developing galls, and that expression of many candidate genes involved in floral development were significantly increased, particularly in later gall stages. The patterns of gene expression found in galls suggest that phylloxera exploits vascular cambium to provide meristematic tissue and redirects leaf development towards formation of carpels. The phylloxera leaf gall appears to be phenotypically and transcriptionally similar to the carpel, due to the parasite hijacking underlying genetic machinery in the host plant.

2013 ◽  
Vol 45 (8) ◽  
pp. 321-331 ◽  
Author(s):  
Gretchen A. Meyer ◽  
Simon Schenk ◽  
Richard L. Lieber

In this work, the interaction between the loss of a primary component of the skeletal muscle cytoskeleton, desmin, and two common physiological stressors, acute mechanical injury and aging, were investigated at the transcriptional, protein, and whole muscle levels. The transcriptional response of desmin knockout ( des −/−) plantarflexors to a bout of 50 eccentric contractions (ECCs) showed substantial overlap with the response in wild-type ( wt) muscle. However, changes in the expression of genes involved in muscle response to injury were blunted in adult des −/− muscle compared with wt (fold change with ECC in des −/− and wt, respectively: Mybph, 1.4 and 2.9; Xirp1, 2.2 and 5.7; Csrp3, 1.8 and 4.3), similar to the observed blunted mechanical response (torque drop: des −/− 30.3% and wt 55.5%). Interestingly, in the absence of stressors, des −/− muscle exhibited elevated expression of many these genes compared with wt. The largest transcriptional changes were observed in the interaction between aging and the absence of desmin, including many genes related to slow fiber pathway (Myh7, Myl3, Atp2a2, and Casq2) and insulin sensitivity (Tlr4, Trib3, Pdk3, and Pdk4). Consistent with these transcriptional changes, adult des −/− muscle exhibited a significant fiber type shift from fast to slow isoforms of myosin heavy chain ( wt, 5.3% IIa and 71.7% IIb; des −/−, 8.4% IIa and 61.4% IIb) and a decreased insulin-stimulated glucose uptake ( wt, 0.188 μmol/g muscle/20 min; des −/−, 0.085 μmol/g muscle/20 min). This work points to novel areas of influence of this cytoskeletal protein and directs future work to elucidate its function.


2015 ◽  
Vol 81 (7) ◽  
pp. 2554-2561 ◽  
Author(s):  
Onur Ercan ◽  
Michiel Wels ◽  
Eddy J. Smid ◽  
Michiel Kleerebezem

ABSTRACTThis paper describes the transcriptional adaptations of nongrowing, retentostat cultures ofLactococcus lactisto starvation. Near-zero-growth cultures (μ = 0.0001 h−1) obtained by extended retentostat cultivation were exposed to starvation by termination of the medium supply for 24 h, followed by a recovery period of another 24 h by reinitiating the medium supply to the retentostat culture. During starvation, the viability of the culture was largely retained, and the expression of genes involved in transcription and translational machineries, cell division, and cell membrane energy metabolism was strongly repressed. Expression of these genes was largely recovered following the reinitiation of the medium supply. Starvation triggered the elevated expression of genes associated with synthesis of branched-chain amino acids, histidine, purine, and riboflavin. The expression of these biosynthesis genes was found to remain at an elevated level after reinitiation of the medium supply. In addition, starvation induced the complete gene set predicted to be involved in natural competence inL. lactisKF147, and the elevated expression of these genes was sustained during the subsequent recovery period, but our attempts to experimentally demonstrate natural transformation in these cells failed. Mining the starvation response gene set identified a conservedcis-acting element that resembles the lactococcal CodY motif in the upstream regions of genes associated with transcription and translational machineries, purine biosynthesis, and natural transformation inL. lactis, suggesting a role for CodY in the observed transcriptome adaptations to starvation in nongrowing cells.


Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.


2013 ◽  
Vol 41 (2) ◽  
pp. 472 ◽  
Author(s):  
Carmen F. POPESCU ◽  
Liviu C. DEJEU ◽  
Rafael R. OCETE

The individuals belonging to three different groups of wild grapevines populations Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi harvested along, or near the Danube River, were described by means of usual ampelographic methods. The twenty standardized descriptors used for morphological analysis revealed obvious differentiation among analyzed populations. Out of 65 individuals, a half produced flowers with separate sex and a high proportion of them were males (70%). Pollen measurements on light microscope provided information on differences in pollen size among inside wild grapevine populations of V. sylvestris with the polar length varying between 15.3 and 23 μm and the equatorial length between 15.5 and 24.4μm. The in vitro regenerative potential from meristematic tissue tested with each phenotype showed that the moment of differentiation, the aspect of proliferative structures and the rate of multiplication varied inside these wild grapevine populations, without any correlation with the location of harvesting. Our results provided valuable information about these Vitis vinifera ssp. sylvestris populations, possible to be used as starting plant material for research in general and further breeding of cultivars and grapevine rootstocks.


2020 ◽  
Vol 28 (4) ◽  
pp. 327-334
Author(s):  
Mahan Mohammadi ◽  
Shiva Irani ◽  
Iman Salahshourifar ◽  
Jalil Hosseini ◽  
Afshin Moradi ◽  
...  

BACKGROUND AND AIM: Prostate cancer is the leading cause of death in many countries. It is important to diagnose the disease in the early stages. Current methods detect the disease with low specificity. Examining the expression of genes responsible for disease and their epigenetic regulators are good tools in this regard. MATERIAL AND METHODS: In this prospective case-control study, 40 Iranian patients with cancer, 40 Iranian patients with prostate hyperplasia, and 40 control samples were examined. After blood sampling from each individual, RNA extraction and cDNA synthesis, GSTP1, HDAC, DNMT3A, and DNMT3B expressions were measured in three understudy groups using specific primers and Real-Time PCR method. RESULTS: A reverse correlation was identified between loss of GSTP1 expression and overexpression of HDAC, DNMT3A, and DNMT3B (P value < 0.0001) with a beneficial pattern of cancer development with high efficiency. The significant decrease of GSTP1 expression in patients in comparison to the healthy controls and the elevated expression levels of the studied epigenetic regulators in PCA and BPH samples indicate the impact of the regulators on GSTP1 expression activity. CONCLUSION: This study showed that the measurement of combined GSTP1 and its epigenetic regulators’ expression could be used as suitable genetic markers for the detection and separation of healthy individuals from prostatic patient groups in the Iranian population. However, a similar study in a larger population of case and control could help us to distinguish between normal, benign, and malignant conditions.


2020 ◽  
Vol 375 (1801) ◽  
pp. 20190400 ◽  
Author(s):  
Naresh Loudya ◽  
Tolulope Okunola ◽  
Jia He ◽  
Paul Jarvis ◽  
Enrique López-Juez

Defects in chloroplast development are ‘retrograde-signalled’ to the nucleus, reducing synthesis of photosynthetic or related proteins. The Arabidopsis cue8 mutant manifests virescence, a slow-greening phenotype, and is defective at an early stage in plastid development. Greening cotyledons or early leaf cells of cue8 exhibit immature chloroplasts which fail to fill the available cellular space. Such chloroplasts show reduced expression of genes of photosynthetic function, dependent on the plastid-encoded polymerase (PEP), while the expression of genes of housekeeping function driven by the nucleus-encoded polymerase (NEP) is elevated, a phenotype shared with mutants in plastid genetic functions. We attribute this phenotype to reduced expression of specific PEP-controlling sigma factors, elevated expression of RPOT (NEP) genes and maintained replication of plastid genomes (resulting in densely coalesced nucleoids in the mutant), i.e. it is due to an anterograde nucleus-to-chloroplast correction, analogous to retention of a juvenile plastid state. Mutants in plastid protein import components, particularly those involved in housekeeping protein import, also show this ‘retro-anterograde’ correction. Loss of CUE8 also causes changes in mRNA editing. The overall response has strong fitness value: loss of GUN1, an integrator of retrograde signalling, abolishes elements of it (albeit not others, including editing changes), causing bleaching and eventual seedling lethality upon cue8 gun1 . This highlights the adaptive significance of virescence and retrograde signalling. This article is part of the theme issue ‘Retrograde signalling from endosymbiotic organelles’.


2002 ◽  
Vol 76 (23) ◽  
pp. 11960-11970 ◽  
Author(s):  
Jarmila Kralova ◽  
Andrew S. Liss ◽  
William Bargmann ◽  
Cullen Pendleton ◽  
Janani Varadarajan ◽  
...  

ABSTRACT The v-rel oncogene encoded by reticuloendotheliosis virus is the acutely transforming member of the Rel/NF-κB family of transcription factors. v-Rel is a truncated and mutated form of c-Rel and transforms cells by inducing the aberrant expression of genes regulated by Rel/NF-κB proteins. The expression of ch-IAP1, a member of the inhibitor-of-apoptosis family, is highly elevated in cells expressing v-Rel and contributes to the immortalization of cells transformed by this oncoprotein. In this study we demonstrate that the elevated expression of ch-IAP1 in v-Rel-expressing cells is due to an increased rate of transcription. The ch-IAP1 promoter was isolated, and four Rel/NF-κB binding sites were identified upstream of the transcription start site. Two κB sites proximal to the transcription start site were required for v-Rel to activate the ch-IAP1 promoter. While c-Rel also utilized these sites, a third more-distal κB site was required for its full activation of the ch-IAP1 promoter. Differences in the transactivation domains of v-Rel and c-Rel are responsible for their different abilities to utilize these sites and account for their differential activation of the ch-IAP1 promoter. Although c-Rel was a more potent activator of the ch-IAP1 promoter than v-Rel in transient reporter assays, cells stably overexpressing c-Rel failed to maintain high levels of ch-IAP1 expression. The reduction of ch-IAP1 expression in these cells correlated with the efficient regulation of c-Rel by IκBα. The ability of v-Rel to escape IκBα regulation allows for the gradual and sustained elevation of ch-IAP1 expression directly contributing to the transforming properties of v-Rel.


2020 ◽  
Author(s):  
Yang Yang ◽  
Dan Xing ◽  
Yawei Wang ◽  
Haobo Jia ◽  
Bing Li ◽  
...  

Abstract Background: Long noncoding RNAs (lncRNAs) are recently found to be critical regulators of the epigenome. However, our knowledge of their role in osteoarthritis (OA) development is limited. This study investigates the mechanism by which HOTAIR, a key lncRNA with elevated expression in OA, affects OA disease progression.Results: HOTAIR expression was greatly elevated in osteoarthritic compared to normal chondrocytes. Silencing and over-expression of HOTAIR in SW1353 cells respectively reduced and increased the expression of genes associated with cartilage degradation in OA. Investigation of molecular pathways revealed that HOTAIR acted directly on Wnt inhibitory factor 1 (WIF-1) by increasing histone H3K27 trimethylation in the WIF-1 promoter, leading to WIF-1 repression that favours activation of the Wnt/β-catenin pathway.Conclusions: Activation of Wnt/β-catenin signalling by HOTAIR through WIF-1 repression in osteoarthritic chondrocytes increases catabolic gene expression and promotes cartilage degradation. This is the first study to demonstrate a direct link between HOTAIR, WIF-1 and OA progression, which may be useful for future investigations into disease biomarkers or therapeutic targets.


Author(s):  
Vishal Musale ◽  
R Charlotte Moffett ◽  
Bosede Owolabi ◽  
J. Michael Conlon ◽  
Peter R Flatt ◽  
...  

The anti-diabetic effects and mechanisms of action of an analogue of a frog skin host-defence peptide belonging to the caerulein-precursor fragment family, [S4K]CPF-AM1 were investigated in db/db mice with a genetically inherited form of degenerative diabetes-obesity. Twice-daily treatment with the peptide (75 nmol/kg body weight) for 28 days significantly decreased blood glucose (P<0.01) and HbA1c (P<0.05) and increased plasma insulin (P<0.05) concentrations with no effect on body weight, energy intake, body composition or plasma lipid profile. Peptide administration improved insulin sensitivity and intraperitoneal glucose tolerance. Elevated biomarkers of liver and kidney function associated with the db/db phenotype were significantly lowered by [S4K]CPF-AM1 administration. Peptide treatment significantly (P<0.05) increased pancreatic insulin content and improved the responses of isolated islets to established secretagogues. Elevated expression of genes associated with insulin signalling (Slc2a4, Insr, Irs1, Akt1, Pik3ca, Ppm1b) in the skeletal muscle of db/db mice were significantly downregulated by peptide treatment. Genes associated with insulin secretion (Abcc8, Kcnj11, Slc2a2, Cacn1c, Glp1r, Gipr) were significantly upregulated by treatment with [S4K]CPF-AM1. Studies with BRIN-BD1I clonal β-cells demonstrated that the peptide evoked membrane depolarization, increased intracellular Ca2+ and cAMP and activated the protein kinase C pathway. The data indicate that the anti-diabetic properties of [S4K]CPF-AM1 mice are mediated by direct insulinotropic action and by regulation of transcription of genes involved in both the secretion and action of insulin.


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