scholarly journals Comparative Transcriptomic Analysis of the Development of Sepal Morphology in Tomato (Solanum Lycopersicum L.)

2020 ◽  
Vol 21 (16) ◽  
pp. 5914
Author(s):  
Jingyi Liu ◽  
Meijing Shi ◽  
Jing Wang ◽  
Bo Zhang ◽  
Yushun Li ◽  
...  
Keyword(s):  
Cell Expansion ◽  
Natural Variation ◽  
Wild Type ◽  
Negative Regulators ◽  
Commercial Property ◽  
Developmental Mechanism ◽  
Solanum Lycopersicum L ◽  
Positive Regulators ◽  
Key Genes ◽  
Comparative Transcriptomic Analysis

Sepal is an important component of the tomato flower and fruit that typically protects the flower in bud and functions as a support for petals and fruits. Moreover, sepal appearance influences the commercial property of tomato nowadays. However, the phenotype information and development mechanism of the natural variation of sepal morphology in the tomato is still largely unexplored. To study the developmental mechanism and to determine key genes related to downward sepal in the tomato, we compared the transcriptomes of sepals between downward sepal (dsp) mutation and the wild-type by RNA sequencing and found that the differentially expressed genes were dominantly related to cell expansion, auxin, gibberellins and cytokinin. dsp mutation affected cell size and auxin, and gibberellins and cytokinin contents in sepals. The results showed that cell enlargement or abnormal cell expansion in the adaxial part of sepals in dsp. As reported, auxin, gibberellins and cytokinin were important factors for cell expansion. Hence, dsp mutation regulated cell expansion to control sepal morphology, and auxin, gibberellins and cytokinin may mediate this process. One ARF gene and nine SAUR genes were dramatically upregulated in the sepal of the dsp mutant, whereas seven AUX/IAA genes were significantly downregulated in the sepal of dsp mutant. Further bioinformatic analyses implied that seven AUX/IAA genes might function as negative regulators, while one ARF gene and nine SAUR genes might serve as positive regulators of auxin signal transduction, thereby contributing to cell expansion in dsp sepal. Thus, our data suggest that 17 auxin-responsive genes are involved in downward sepal formation in the tomato. This study provides valuable information for dissecting the molecular mechanism of sepal morphology control in the tomato.

Apoptosis in late stage Drosophila nurse cells does not require genes within the H99 deficiency

Development ◽  
1998 ◽  
Vol 125 (6) ◽  
pp. 1075-1082 ◽  
Author(s):  
K. Foley ◽  
L. Cooley
Keyword(s):  
Dna Fragmentation ◽  
Late Stage ◽  
Expression Patterns ◽  
Nuclear Material ◽  
Nurse Cells ◽  
Wild Type ◽  
Negative Regulators ◽  
Egg Chambers ◽  
Positive Regulators ◽  
Egg Chamber

We have determined that nurse cells are cleared from the Drosophila egg chamber by apoptosis. DNA fragmentation begins in nurse cells at stage 12, following the completion of cytoplasm transfer from the nurse cells to the oocyte. During stage 13, nurse cells increasingly contain highly fragmented DNA and disappear from the egg chamber concomitantly with the formation of apoptotic vesicles containing highly fragmented nuclear material. In dumpless mutant egg chambers that fail to complete cytoplasm transport from the nurse cells, DNA fragmentation is markedly delayed and begins during stage 13, when the majority of cytoplasm is lost from the nurse cells. These data suggest the presence of cytoplasmic factors in nurse cells that inhibit the initiation of DNA fragmentation. In addition, we have examined the ovarian expression patterns of regulatory genes implicated in Drosophila apoptosis. The positive regulators, reaper (rpr), head involution defective (hid) and grim, as well as the negative regulators, DIAP1 and DIAP2, are transcribed during oogenesis. However, germline clones homozygous for the deficiency Df(3)H99, which deletes rpr, hid and grim, undergo oogenesis in a manner morphologically indistinguishable from wild type, indicating that genes within this region are not necessary for apoptosis in nurse cells.

scholarly journals Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Veronica Giourieva ◽  
Emmanuel Panteris
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Cell Expansion ◽  
Cortical Microtubule ◽  
Root Apex ◽  
Cellulose Synthase ◽  
Cellulose Biosynthesis ◽  
Cortical Microtubules ◽  
Wild Type ◽  
Microtubule Stability

Abstract Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules.

scholarly journals Genetic mapping and transcriptomic characterization of a new fuzzless-tufted cottonseed mutant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qian-Hao Zhu ◽  
Warwick Stiller ◽  
Philippe Moncuquet ◽  
Stuart Gordon ◽  
Yuman Yuan ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Agronomic Traits ◽  
Gene Families ◽  
Mutant Phenotype ◽  
Wild Type ◽  
Calcium Dependent ◽  
Dependent Protein ◽  
Flanking Region ◽  
Comparative Transcriptomic Analysis

Abstract Fiber mutants are unique and valuable resources for understanding the genetic and molecular mechanisms controlling initiation and development of cotton fibers that are extremely elongated single epidermal cells protruding from the seed coat of cottonseeds. In this study, we reported a new fuzzless-tufted cotton mutant (Gossypium hirsutum) and showed that fuzzless-tufted near-isogenic lines (NILs) had similar agronomic traits and a higher ginning efficiency compared to their recurrent parents with normal fuzzy seeds. Genetic analysis revealed that the mutant phenotype is determined by a single incomplete dominant locus, designated N5. The mutation was fine mapped to an approximately 250-kb interval containing 33 annotated genes using a combination of bulked segregant sequencing, SNP chip genotyping, and fine mapping. Comparative transcriptomic analysis using 0–6 days post-anthesis (dpa) ovules from NILs segregating for the phenotypes of fuzzless-tufted (mutant) and normal fuzzy cottonseeds (wild-type) uncovered candidate genes responsible for the mutant phenotype. It also revealed that the flanking region of the N5 locus is enriched with differentially expressed genes (DEGs) between the mutant and wild-type. Several of those DEGs are members of the gene families with demonstrated roles in cell initiation and elongation, such as calcium-dependent protein kinase and expansin. The transcriptome landscape of the mutant was significantly reprogrammed in the 6 dpa ovules and, to a less extent, in the 0 dpa ovules, but not in the 2 and 4 dpa ovules. At both 0 and 6 dpa, the reprogrammed mutant transcriptome was mainly associated with cell wall modifications and transmembrane transportation, while transcription factor activity was significantly altered in the 6 dpa mutant ovules. These results imply a similar molecular basis for initiation of lint and fuzz fibers despite certain differences.

scholarly journals Strigolactones Control Root System Architecture and Tip Anatomy in Solanum lycopersicum L. Plants under P Starvation

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 612 ◽  
Author(s):  
Veronica Santoro ◽  
Michela Schiavon ◽  
Francesco Gresta ◽  
Andrea Ertani ◽  
Francesca Cardinale ◽  
...  
Keyword(s):  
Solanum Lycopersicum ◽  
Lateral Root ◽  
Primary Root ◽  
Root Traits ◽  
Root System Architecture ◽  
Root Tip ◽  
Root Number ◽  
Wild Type ◽  
Solanum Lycopersicum L ◽  
P Supply

The hormones strigolactones accumulate in plant roots under phosphorus (P) shortage, inducing variations in plant phenotype. In this study, we aimed at understanding whether strigolactones control morphological and anatomical changes in tomato (Solanum lycopersicum L.) roots under varying P supply. Root traits were evaluated in wild-type seedlings grown in high vs. low P, with or without exogenous strigolactones, and in wild-type and strigolactone-depleted plants grown first under high vs. no P, and then under high vs. no P after acclimation on low P. Exogenous strigolactones stimulated primary root and lateral root number under low P. Root growth was reduced in strigolactone-depleted plants maintained under continuous P deprivation. Total root and root hair length, lateral root number and root tip anatomy were impaired by low strigolactone biosynthesis in plants grown under low P or transferred from low to no P. Under adequate P conditions, root traits of strigolactone-depleted and wild-type plants were similar. Concluding, our results indicate that strigolactones (i) control macro- and microscopic changes of root in tomato depending on P supply; and (ii) do not affect root traits significantly when plants are supplemented with adequate P, but are needed for acclimation to no P and typical responses to low P.

scholarly journals Sp1 trans-activates and is required for maximal aldosterone induction of the αENaC gene in collecting duct cells

2013 ◽  
Vol 305 (5) ◽  
pp. F653-F662 ◽  
Author(s):  
Zhiyuan Yu ◽  
Qun Kong ◽  
Bruce C. Kone
Keyword(s):  
Collecting Duct ◽  
Sodium Absorption ◽  
Sodium Reabsorption ◽  
Wild Type ◽  
Cis Element ◽  
Rate Limiting Step ◽  
Positive Regulators ◽  
Maximal Induction ◽  
Epigenetic Repression

The epithelial Na+ channel (ENaC) in the distal nephron constitutes the rate-limiting step for renal sodium reabsorption. Aldosterone increases tubular sodium absorption in large part by increasing αENaC transcription in collecting duct principal cells. We previously reported that Af9 binds to +78/+92 of αENaC and recruits Dot1a to repress basal and aldosterone-sensitive αENaC transcription in mouse inner medullary collecting duct (mIMCD)3 cells. Despite this epigenetic repression, basal αENaC transcription is still evident and physiologically necessary, indicating basal operation of positive regulators. In the present study, we identified Sp1 as one such regulator. Gel shift and antibody competition assays using a +208/+240 probe revealed DNA-Sp1-containing complexes in mIMCD3 cells. Mutation of the +222/+229 element abrogated Sp1 binding in vitro and in promoter-reporter constructs stably expressed in mIMCD3 cells. Compared with the wild-type promoter, an αENaC promoter-luciferase construct with +222/+229 mutations exhibited much lower activity and impaired trans-activation in Sp1 overexpression experiments. Conversely, Sp1 knockdown inhibited endogenous αENaC mRNA and the activity of the wild-type αENaC promoter but not the mutated construct. Aldosterone triggered Sp1 recruitment to the αENaC promoter, which was required for maximal induction of αENaC promoter activity and was blocked by spironolactone. Sequential chromatin immunoprecipitation assays and functional tests of +78/+92 and +222/+229 αENaC promoter mutants indicated that while Sp1, Dot1a, and Af9 co-occupy the αENaC promoter, the Sp1 effects are functionally independent from Dot1a and Af9. In summary, Sp1 binding to a cis-element at +222/+229 represents the first identified constitutive driver of αENaC transcription, and it contributes to maximal aldosterone trans-activation of αENaC.

Identification of chromosomal deficiency by flow cytometry and cytogenetics in mutant tomato (Solanum lycopersicum, Solanaceae) plants

2009 ◽  
Vol 57 (5) ◽  
pp. 444 ◽  
Author(s):  
Isane Vera Karsburg ◽  
Carlos Roberto Carvalho ◽  
Wellington Ronildo Clarindo
Keyword(s):  
Flow Cytometry ◽  
Solanum Lycopersicum ◽  
Dna Content ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Chromosome 1 ◽  
Wild Type ◽  
Extrinsic Factors ◽  
Solanum Lycopersicum L ◽  
Morphogenic Process

Structural chromosomal aberrations can occur spontaneously in plant karyotypes as a result of both intrinsic and extrinsic factors. These aberrations may affect sporophyte fitness because fundamental genes involved with distinct morphogenic process may be lost. Inadequate development of flowers and anomalous fruits without seeds has been observed in plants of Solanum lycopersicum L. (Solanaceae) ‘BHG 160’ of the tomato germplasm bank (Universidade Federal de Viçosa, Brazil). The nuclear DNA content, quantified by flow cytometry, showed that mutant ‘BHG 160’ possesses 0.09 pg (4.59%) less nuclear DNA content than does the wild-type ‘BGH 160’. Improved cytogenetical preparations evidenced that this difference was due to a spontaneous terminal deficiency in the short arm of the mutant ‘BGH 160’ Chromosome 1. These results suggest that the genes encoded in the short arm of Chromosome 1 may be involved in the development of flowers and fruits in the tomato.

Influence of overexpression of a gibberellin 20-oxidase gene on the kinetics of xylem cell development in hybrid poplar (Populus tremula L. and P. tremuloides Michx.)

Holzforschung ◽  
2006 ◽  
Vol 60 (6) ◽  
pp. 608-617 ◽  
Author(s):  
Oliver Dünisch ◽  
Matthias Fladung ◽  
Satoshi Nakaba ◽  
Yoko Watanabe ◽  
Ryo Funada
Keyword(s):  
Transgenic Plants ◽  
Cell Expansion ◽  
Hybrid Poplar ◽  
Cell Development ◽  
Populus Tremula ◽  
Uv Spectrophotometry ◽  
Wild Type ◽  
Oxidase Gene ◽  
Xylem Cell ◽  
Kinetics Of

Abstract Gibberellins (GAs) are important regulators of shoot growth in trees. We studied the kinetics of xylem formation in hybrid poplar (Populus tremula L.×P. tremuloides Michx.) in which the key regulatory gene gibberellin acid 20 oxidase (GA20-oxidase) isolated from Arabidopsis is overexpressed. Increments in the height and radius of shoots were registered by high-resolution laser measurements. The anatomical and chemical structure of mature xylem cells was studied by light electron microscopy and UV spectrophotometry. Transgenic plants showed an increase in height growth, but a lower speed of cell elongation during primary growth compared to wild-type plants. During the first year of growth, transgenic plants showed a higher radius increment, an increase in the period of cell expansion of vessels and fibres and their final size, and a higher lignin content of the compound middle lamella between fibres compared to wild-type plants. In contrast, during the third year of growth, only a slight increase in the period of cell expansion of fibre cells was observed in transgenic compared to wild-type plants. Analyses of GA20-oxidase expression in leaves and shoots of 6-month- and 3-year-old plants of three different independent transgenic lines revealed a decrease in its expression only in shoots but not in leaves of the 3-year-old plants. The results indicate that overexpression of the GA20-oxidase gene in young shoots of transgenic poplar predominately affects cell expansion, while no GA20-oxidase expression was observed in shoots of 3-year-old transgenic plants, resulting in wild-type xylem cell development.

scholarly journals A Dominant-Negative PPARγMutant Promotes Cell Cycle Progression and Cell Growth in Vascular Smooth Muscle Cells

PPAR Research ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Joey Z. Liu ◽  
Christopher J. Lyon ◽  
Willa A. Hsueh ◽  
Ronald E. Law
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Cell Cycle Progression ◽  
Muscle Cells ◽  
Dominant Negative ◽  
Wild Type ◽  
Cycle Progression ◽  
Positive Regulators

PPARγligands have been shown to have antiproliferative effects on many cell types. We herein report that a synthetic dominant-negative (DN) PPARγmutant functions like a growth factor to promote cell cycle progression and cell proliferation in human coronary artery smooth muscle cells (CASMCs). In quiescent CASMCs, adenovirus-expressed DN-PPARγpromoted G1→S cell cycle progression, enhanced BrdU incorporation, and increased cell proliferation. DN-PPARγexpression also markedly enhanced positive regulators of the cell cycle, increasing Rb and CDC2 phosphorylation and the expression of cyclin A, B1, D1, and MCM7. Conversely, overexpression of wild-type (WT) or constitutively-active (CA) PPARγinhibited cell cycle progression and the activity and expression of positive regulators of the cell cycle. DN-PPARγexpression, however, did not up-regulate positive cell cycle regulators in PPARγ-deficient cells, strongly suggesting that DN-PPARγeffects on cell cycle result from blocking the function of endogenous wild-type PPARγ. DN-PPARγexpression enhanced phosphorylation of ERK MAPKs. Furthermore, the ERK specific-inhibitor PD98059 blocked DN-PPARγ-induced phosphorylation of Rb and expression of cyclin A and MCM7. Our data thus suggest that DN-PPARγpromotes cell cycle progression and cell growth in CASMCs by modulating fundamental cell cycle regulatory proteins and MAPK mitogenic signaling pathways in vascular smooth muscle cells (VSMCs).

Loss of Wild-Type Jak2 Allele Enhances Myeloid Cell Expansion and Accelerates Myelofibrosis in Jak2V617F Knock-in Mice

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 809-809
Author(s):  
Hajime Akada ◽  
Saeko Akada ◽  
Dongqing Yan ◽  
Robert Hutchison ◽  
Golam Mohi
Keyword(s):  
Polycythemia Vera ◽  
Cell Expansion ◽  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasms ◽  
Philadelphia Chromosome ◽  
Myeloid Cell ◽  
Negative Regulator ◽  
Jak2v617f Mutation ◽  
Common Mutation ◽  
Wild Type

Abstract Abstract 809 The activating JAK2V617F mutation is the most common mutation found in Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs), which include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). Although a majority of MPN patients carry heterozygous JAK2V617F mutation, loss of heterozygosity (LOH) on chromosome 9p involving JAK2 has been observed in ∼30% of patients with MPNs particularly in PV and PMF. JAK2V617F homozygosity through 9pLOH has been linked to more severe MPN phenotype. However, the contribution of 9pLOH in the pathogenesis of MPNs remains unclear. To investigate the role of wild-type JAK2 in MPNs induced by JAK2V617F, we have utilized conditional Jak2 knock-out and Jak2V617F knock-in alleles and generated heterozygous, hemizygous and homozygous Jak2V617F mice. Whereas heterozygous Jak2V617F expression results in a polycythemia vera-like disease in mice, loss of wild-type Jak2 allele in hemizygous or homozygous Jak2V617F mice results in a significantly greater increase in reticulocytes, white blood cells, neutrophils and platelets in the peripheral blood and larger spleen size. We also have found that hemizygous or homozygous Jak2V617F expression significantly increased megakaryocyte-erythroid progenitors in the bone marrow and spleens and marked infiltration of neutrophils in the liver compared with heterozygous Jak2V617F. More importantly, hemizygous or homozygous Jak2V617F mice show accelerated myelofibrosis compared with heterozygous Jak2V617F-expressing mice. Thus, loss of wild type Jak2 allele increases myeloid cell expansion and enhances the severity of the MPN. Together, these results suggest that wild-type Jak2 serves as a negative regulator of MPN induced by Jak2V617F. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Identification and Characterization of Genes Required for Early Myxococcus xanthus Developmental Gene Expression

2000 ◽  
Vol 182 (16) ◽  
pp. 4564-4571 ◽  
Author(s):  
Dongchuan Guo ◽  
Yun Wu ◽  
Heidi B. Kaplan
Keyword(s):  
Response Regulator ◽  
Myxococcus Xanthus ◽  
Normal Growth ◽  
Negative Regulator ◽  
Developmental Expression ◽  
Wild Type ◽  
Developmental Gene ◽  
O Antigen ◽  
New Genes ◽  
Positive Regulators

ABSTRACT Starvation and cell density regulate the developmental expression of Myxococcus xanthus gene 4521. Three classes of mutants allow expression of this developmental gene during growth on nutrient agar, such that colonies of strains containing a Tn5 lac Ω4521 fusion are Lac+. One class of these mutants inactivates SasN, a negative regulator of 4521expression; another class activates SasS, a sensor kinase-positive regulator of 4521 expression; and a third class blocks lipopolysaccharide (LPS) O-antigen biosynthesis. To identify additional positive regulators of 4521 expression, 11 Lac− TnV.AS transposon insertion mutants were isolated from a screen of 18,000 Lac+ LPS O-antigen mutants containing Tn5 lac Ω4521 (Tcr). Ten mutations identified genes that could encode positive regulators of4521 developmental expression based on their ability to abolish 4521 expression during development in the absence of LPS O antigen and in an otherwise wild-type background. Eight of these mutations mapped to the sasB locus, which encodes the known 4521 regulators SasS and SasN. One mapped tosasS, whereas seven identified new genes. Three mutations mapped to a gene encoding an NtrC-like response regulator homologue, designated sasR, and four others mapped to a gene designated sasP. One mutation, designatedssp10, specifically suppressed the LPS O-antigen defect; the ssp10 mutation had no effect on 4521expression in an otherwise wild-type background but reduced4521 developmental expression in the absence of LPS O antigen to a level close to that of the parent strain. All of the mutations except those in sasP conferred defects during growth and development. These data indicate that a number of elements are required for 4521 developmental expression and that most of these are necessary for normal growth and fruiting body development.

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