scholarly journals Root Patterning: Tuning SHORT ROOT Function Creates Diversity in Form

2021 ◽  
Vol 12 ◽  
Author(s):  
Marcela Hernández-Coronado ◽  
Carlos Ortiz-Ramírez
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Morphological Diversity ◽  
Genetic Circuit ◽  
Biotic And Abiotic Stress ◽  
Short Root ◽  
Symbiotic Associations ◽  
Radial Patterning ◽  
Developmental Patterning ◽  
Cell Layers

Roots have a fundamental role in plant growth and adaptation to different environments. Diversity in root morphology and architecture enables plants to acquire water and nutrients in contrasting substrate conditions, resist biotic and abiotic stress, and develop symbiotic associations. At its most fundamental level, morphology is determined by discrete changes in tissue patterning. Differences in the number and arrangement of the cell layers in the root can change tissue structure, as well as root length and girth, affecting important productivity traits. Therefore, understanding the molecular mechanisms controlling variation in developmental patterning is an important goal in biology. The ground tissue (GT) system is an ideal model to study the genetic basis of morphological diversity because it displays great interspecific variability in cell layer number. In addition, the genetic circuit controlling GT patterning in Arabidopsis thaliana has been well described, although little is known about species with more complex root anatomies. In this review, we will describe the Arabidopsis model for root radial patterning and present recent progress in elucidating the genetic circuitry controlling GT patterning in monocots and the legume Medicago truncatula (Mt), species that develop roots with more complex anatomies and multilayered cortex.

scholarly journals Genetical control of 2D pattern and depth of the primordial furrow that codes 3D shape of the rhinoceros beetle horn

2020 ◽  
Author(s):  
Haruhiko Adachi ◽  
Keisuke Matsuda ◽  
Teruyuki Niimi ◽  
Shigeru Kondo ◽  
Hiroki Gotoh
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Genetic Factors ◽  
3D Structure ◽  
Gene Knockdown ◽  
3D Shape ◽  
Rhinoceros Beetle ◽  
Blowing Up ◽  
Developmental Patterning ◽  
2D Pattern

AbstractThe head horn of the Asian rhinoceros beetle develops as extensively folded primordia before unfurling into its final 3D shape at the pupal molt. The information of the final 3D structure of the beetle horn is encoded in the folding pattern of the developing primordia. However, the developmental mechanism underlying epithelial folding of the primordia is unknown. In this study, we addressed this gap in our understanding of the developmental patterning of the 3D horn shape of beetles by focusing on the formation of surficial furrows that become the bifurcated 3D shape of the horn. By gene knockdown screening via RNAi, we found that knockdown of the gene Notch disturbed overall horn primordia furrow depth without affecting 2D furrow pattern. In contrast, knockdown of CyclinE altered 2D horn primordia furrow pattern without affecting furrow depth. From these results, depth and 2D pattern of primordial surficial furrow are likely to be regulated independently during the development and both of change can alter the final 3D shape.Author SummaryIn insects, some large structure is made under the old exoskeleton before the molting. Long horn of rhino-beetle is one of extreme cases. The beetle horn is compactly packed as furrowed primordia under the larval exoskeleton. At molting, the primordia is extended to form its final 3D horn shape as blowing up furrows like a balloon. This transformation from primordia to final horn does not required any living cell activities. Thus, characteristics of furrows of primordia actually determine the final 3D shape. However, molecular mechanisms and genetic basis of furrow formation is not well understood not only in beetle horn but also in any other insects. In this study, by using beetle horn as a model, we addressed what kind of genetic factors are contributed to primordial furrow formation. By gene knockdown screening, we found that knockdown of the gene Notch disturbed primordial furrow depth without affecting 2D furrow pattern. In contrast, knockdown of CyclinE altered 2D furrow pattern without affecting furrow depth. In both case, final horn shapes were disturbed. From these results, we concluded that both of the depth and 2D pattern of primordial furrow can contribute final shape, but their development is controlled independently.

Molecular Basis and Clinical Aspects of Hereditary Megakaryocyte and Platelet Membrane Glycoprotein Disorders

1996 ◽  
Vol 16 (02) ◽  
pp. 114-138 ◽  
Author(s):  
R. E. Scharf
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Molecular Genetic ◽  
Platelet Membrane ◽  
Clinical Aspects ◽  
Membrane Glycoprotein ◽  
Membrane Glycoproteins ◽  
Membrane Expression ◽  
Receptor Complexes ◽  
Platelet Membrane Glycoprotein

SummarySpecific membrane glycoproteins (GP) expressed by the megakaryocyte-platelet system, including GPIa-lla, GPIb-V-IX, GPIIb-llla, and GPIV are involved in mediat-ing platelet adhesion to the subendothelial matrix. Among these glycoproteins, GPIIb-llla plays a pivotal role since platelet aggregation is exclusively mediated by this receptor and its interaction with soluble macromolecular proteins. Inherited defects of the GPIIb-llla or GPIb-V-IX receptor complexes are associated with bleeding disorders, known as Glanzmann's thrombasthenia, Bernard-Soulier syndrome, or platelet-type von Willebrand's disease, respectively. Using immuno-chemical and molecular biology techniques, rapid advances in our understanding of the molecular genetic basis of these disorders have been made during the last few years. Moreover, analyses of patients with congenital platelet membrane glycoprotein abnormalities have provided valuable insights into molecular mechanisms that are required for structural and functional integrity, normal biosynthesis of the glycoprotein complexes and coordinated membrane expression of their constituents. The present article reviews the current state of knowledge of the major membrane glycoproteins in health and disease. The spectrum of clinical bleeding manifestations and established diagnostic criteria for each of these dis-orders are summarized. In particular, the variety of molecular defects that have been identified so far and their genetic basis will be discussed.

scholarly journals Plant evolution driven by interactions with symbiotic and pathogenic microbes

Science ◽  
2021 ◽  
Vol 371 (6531) ◽  
pp. eaba6605 ◽  
Author(s):  
Pierre-Marc Delaux ◽  
Sebastian Schornack
Keyword(s):  
Cell Biology ◽  
Genetic Basis ◽  
Reverse Genetics ◽  
Molecular Mechanisms ◽  
Plant Evolution ◽  
Symbiotic Microorganisms ◽  
Protection Mechanisms ◽  
Evolutionary Trajectories ◽  
Microbe Interactions ◽  
Pathogenic Microbes

During 450 million years of diversification on land, plants and microbes have evolved together. This is reflected in today’s continuum of associations, ranging from parasitism to mutualism. Through phylogenetics, cell biology, and reverse genetics extending beyond flowering plants into bryophytes, scientists have started to unravel the genetic basis and evolutionary trajectories of plant-microbe associations. Protection against pathogens and support of beneficial, symbiotic, microorganisms are sustained by a blend of conserved and clade-specific plant mechanisms evolving at different speeds. We propose that symbiosis consistently emerges from the co-option of protection mechanisms and general cell biology principles. Exploring and harnessing the diversity of molecular mechanisms used in nonflowering plant-microbe interactions may extend the possibilities for engineering symbiosis-competent and pathogen-resilient crops.

Molecular Insights into Beneficial Effects of Tea-Plant Growth and Selenium Enrichment by Herbaspirillum camelliae

2021 ◽  
pp. 37-51
Author(s):  
Wei Cheng ◽  
Xuejing Yu ◽  
Xingguo Wang
Keyword(s):  
Plant Growth ◽  
Molecular Mechanisms ◽  
Acc Deaminase ◽  
Nitrogen Sources ◽  
Endophytic Bacterium ◽  
Tea Plant ◽  
Nitrogen Fixing ◽  
Biotic And Abiotic Stress ◽  
Bacterial Strains ◽  
Secretion Systems

Herbaspirillum camelliae WT00C, as a tea-plant endophytic bacterium, not only colonizes specifically in tea plants but also promotes tea-plant growth and selenium enrichment. Different from diazotrophic endophytes H. seropedicae, H. frisingense and H. rubrisubalbicans, H. camelliae WT00C does not display nitrogen-fixing activity. To understand the molecular mechanisms of promoting the growth of tea plant and Se-enrichment, we sequenced and annotated the genome of H. camelliae WT00C. The results showed that the genome was composed of 6,079,821 base pairs with a total of 5,537 genes. The genomic survey also revealed that H. camelliae WT00C was a multifunctional bacterium metabolizing a variety of carbon and nitrogen sources and defending against biotic and abiotic stress. Although this bacterium did not have intact nitrogen-fixing genes, its genome held the genes responsible for indole-3-acetic acid (IAA) biosynthesis, 1-aminocyclopropane-1-carboxylate (ACC) deamination, siderophore synthesis, ammonia formation, urea metabolism, glutathione and selenocompound metabolisms. Biosynthesis of IAA, siderophore, ammonia, urea and ACC deaminase could explain why two bacterial strains promote tea-plant growth and development. Selenocompound metabolism in this bacterium might also benefit tea-plant growth and Se-enrichment. In addition, the genome of H. camelliae also contained a multitude of protein secretion systems T1SS, T3SS, T4SS and T6SS, in which T4SS did not exhibit in other members of the genus Herbaspirillum.

scholarly journals Molecular Evolution of Tubulins in Diatoms

2022 ◽  
Vol 23 (2) ◽  
pp. 618
Author(s):  
Kirill V. Khabudaev ◽  
Darya P. Petrova ◽  
Yekaterina D. Bedoshvili ◽  
Yelena V. Likhoshway ◽  
Mikhail A. Grachev
Keyword(s):  
Amino Acids ◽  
Posttranslational Modification ◽  
Molecular Mechanisms ◽  
Morphological Diversity ◽  
Amino Acid Sequences ◽  
Transcriptome Data ◽  
Eukaryotic Proteins ◽  
Large Diatom ◽  
Species Specific ◽  
Β Tubulin

Microtubules are formed by α- and β-tubulin heterodimers nucleated with γ-tubulin. Tubulins are conserved eukaryotic proteins. Previously, it was shown that microtubules are involved in diatom silica frustule morphogenesis. Diatom frustules are varied, and their morphology is species-specific. Despite the attractiveness of the problem of elucidating the molecular mechanisms of genetically programmed morphogenesis, the structure and evolution of diatom tubulins have not been studied previously. Based on available genomic and transcriptome data, we analyzed the phylogeny of the predicted amino acid sequences of diatom α-, β- and γ-tubulins and identified five groups for α-tubulins, six for β-tubulins and four for γ-tubulins. We identified characteristic amino acids of each of these groups and also analyzed possible posttranslational modification sites of diatom tubulins. According to our results, we assumed what changes occurred in the diatom tubulin structures during their evolution. We also identified which tubulin groups are inherent in large diatom taxa. The similarity between the evolution of diatom tubulins and the evolution of diatoms suggests that molecular changes in α-, β- and γ-tubulins could be one of the factors in the formation of a high morphological diversity of diatoms.

scholarly journals Patterns of genome-wide allele-specific expression in hybrid rice and the implications on the genetic basis of heterosis

2019 ◽  
Vol 116 (12) ◽  
pp. 5653-5658 ◽  
Author(s):  
Lin Shao ◽  
Feng Xing ◽  
Conghao Xu ◽  
Qinghua Zhang ◽  
Jian Che ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Sequencing Data ◽  
Specific Expression ◽  
Allele Specific Expression ◽  
Parental Allele ◽  
Genetic Components ◽  
Genome Wide ◽  
A Genome ◽  
Allele Specific

Utilization of heterosis has greatly increased the productivity of many crops worldwide. Although tremendous progress has been made in characterizing the genetic basis of heterosis using genomic technologies, molecular mechanisms underlying the genetic components are much less understood. Allele-specific expression (ASE), or imbalance between the expression levels of two parental alleles in the hybrid, has been suggested as a mechanism of heterosis. Here, we performed a genome-wide analysis of ASE by comparing the read ratios of the parental alleles in RNA-sequencing data of an elite rice hybrid and its parents using three tissues from plants grown under four conditions. The analysis identified a total of 3,270 genes showing ASE (ASEGs) in various ways, which can be classified into two patterns: consistent ASEGs such that the ASE was biased toward one parental allele in all tissues/conditions, and inconsistent ASEGs such that ASE was found in some but not all tissues/conditions, including direction-shifting ASEGs in which the ASE was biased toward one parental allele in some tissues/conditions while toward the other parental allele in other tissues/conditions. The results suggested that these patterns may have distinct implications in the genetic basis of heterosis: The consistent ASEGs may cause partial to full dominance effects on the traits that they regulate, and direction-shifting ASEGs may cause overdominance. We also showed that ASEGs were significantly enriched in genomic regions that were differentially selected during rice breeding. These ASEGs provide an index of the genes for future pursuit of the genetic and molecular mechanism of heterosis.

The rmc locus does not affect plant interactions or defence-related gene expression when tomato (Solanum lycopersicum) is infected with the root fungal parasite, Rhizoctonia

2006 ◽  
Vol 33 (3) ◽  
pp. 289 ◽  
Author(s):  
Ling-Ling Gao ◽  
F. Andrew Smith ◽  
Sally E. Smith
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Plant Interactions ◽  
Related Gene ◽  
Wild Type ◽  
Cell Layers ◽  
Almost All

A tomato mutant with reduced mycorrhizal colonisation, rmc, confers resistance to almost all arbuscular mycorrhizal (AM) fungal species tested, although there is variation in colonisation of different root cell layers by different fungi and one species of AM fungus can colonise this mutant relatively normally. These variations indicate a high degree of specificity in relation to AM colonisation. We explored the possibility of specificity or otherwise in interactions between rmc and three non-AM root-infecting fungi, Rhizoctonia solani anastomosis groups (AG) 4 and AG8, and binucleate Rhizoctonia (BNR). There were no differences between the wild type tomato 76R and rmc in the speed or extent to which these fungi infected roots or caused disease. Infection by R. solani induced high levels of defence-related gene expression in both tomato genotypes relative to non-infected plants. In contrast, with BNR the expression of these genes was not induced or induced to a much lower extent than with R. solani. The expression of defence-related genes with these two non-AM fungi was very similar in the two plant genotypes. It was different from effects observed during colonisation by AM fungi, which enhanced expression of defence-related genes in rmc compared with the wild type tomato. The specificity and molecular mechanisms of rmc in control of AM colonisation are discussed.

scholarly journals Genetic basis of intracranial aneurysm formation and rupture: clinical implications in the postgenomic era

2019 ◽  
Vol 47 (1) ◽  
pp. E10 ◽  
Author(s):  
Nardin Samuel ◽  
Ivan Radovanovic
Keyword(s):  
Intracranial Aneurysm ◽  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Association Studies ◽  
Genome Wide Association Studies ◽  
Genetic Aberrations ◽  
Aneurysm Formation ◽  
Genome Wide ◽  
Risk Of Rupture

OBJECTIVEDespite the prevalence and impact of intracranial aneurysms (IAs), the molecular basis of their pathogenesis remains largely unknown. Moreover, there is a dearth of clinically validated biomarkers to efficiently screen patients with IAs and prognosticate risk for rupture. The aim of this study was to survey the literature to systematically identify the spectrum of genetic aberrations that have been identified in IA formation and risk of rupture.METHODSA literature search was performed using the Medical Subject Headings (MeSH) system of databases including PubMed, EMBASE, and Google Scholar. Relevant studies that reported on genetic analyses of IAs, rupture risk, and long-term outcomes were included in the qualitative analysis.RESULTSA total of 114 studies were reviewed and 65 were included in the qualitative synthesis. There are several well-established mendelian syndromes that confer risk to IAs, with variable frequency. Linkage analyses, genome-wide association studies, candidate gene studies, and exome sequencing identify several recurrent polymorphic variants at candidate loci, and genes associated with the risk of aneurysm formation and rupture, including ANRIL (CDKN2B-AS1, 9p21), ARGHEF17 (11q13), ELN (7q11), SERPINA3 (14q32), and SOX17 (8q11). In addition, polymorphisms in eNOS/NOS3 (7q36) may serve as predictive markers for outcomes following intracranial aneurysm rupture. Genetic aberrations identified to date converge on posited molecular mechanisms involved in vascular remodeling, with strong implications for an associated immune-mediated inflammatory response.CONCLUSIONSComprehensive studies of IA formation and rupture have identified candidate risk variants and loci; however, further genome-wide analyses are needed to identify high-confidence genetic aberrations. The literature supports a role for several risk loci in aneurysm formation and rupture with putative candidate genes. A thorough understanding of the genetic basis governing risk of IA development and the resultant aneurysmal subarachnoid hemorrhage may aid in screening, clinical management, and risk stratification of these patients, and it may also enable identification of putative mechanisms for future drug development.

Altered Root Structure Affects Both Expression and Cellular Localization of Transporters for Mineral Element Uptake in Rice

2019 ◽  
Vol 61 (3) ◽  
pp. 481-491 ◽  
Author(s):  
En Yu ◽  
Naoki Yamaji ◽  
Jian Feng Ma
Keyword(s):  
Cellular Localization ◽  
Dry Weight ◽  
Mineral Elements ◽  
Outer Cell ◽  
Mineral Element ◽  
Root Structure ◽  
Short Root ◽  
Element Uptake ◽  
Rice Mutant ◽  
Cell Layers

Abstract One of the most important roles of plant roots is to take up mineral elements for their growth. Although several genes involved in root growth have been identified, the association between root structure and mineral element uptake is less investigated. In this study, we isolated a rice mutant (dice1, defective in cell elongation 1) with short-root phenotype. This mutant was characterized by partial defect in the formation of root outer cell layers. Mapping of the responsible gene revealed that the short-root phenotype in the mutant was caused by a single-nucleotide substitution of a gene encoding a membrane-anchored endo-1,4-beta-glucanase (OsGlu3). The growth of both the roots and shoots was partially recovered with increasing strength of nutrient solution and glucose in the mutant. The mutant showed a decreased uptake (normalized by root dry weight) for Mg, Mn, Fe, Cu, Zn, Cd, As and Ge but increased uptake for K and Ca. The expression level of some transporter genes including OsLsi1 and OsLsi2 for Si uptake and OsNramp5 for Mn uptake was significantly decreased in the mutant compared with the wild-type (WT) rice. Furthermore, the cellular localization of OsLsi1 was altered; OsLsi1 localized at the root exodermis of the WT rice was changed to be localized to other cell layers of the mutant roots. However, this localization became normal in the presence of exogenous glucose in the mutant. Our results indicate that a normal root structure is required for maintaining the expression and localization of transporters involved in the mineral element uptake.

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