scholarly journals Regulation of suberin biosynthesis and Casparian strip development in the root endodermis by two plant auxins

2021 ◽  
Author(s):  
Sam David Cook ◽  
Seisuke Kimura ◽  
Qi Wu ◽  
Rochus Franke ◽  
Takehiro Kamiya ◽  
...  
Keyword(s):  
Phenylacetic Acid ◽  
Biological Function ◽  
Treatment Results ◽  
Casparian Strip ◽  
Barrier Formation ◽  
Identical Manner ◽  
Development And Differentiation ◽  
Barrier Regulation ◽  
Indole 3 Acetic Acid ◽  
Root Endodermis

The biological function of the auxin phenylacetic acid (PAA) is not well characterized in plants. Although some aspects of its biology; transport, signaling and metabolism have recently been described. Previous work on this phytohormone has suggested that PAA behaves in an identical manner to IAA (indole-3-acetic acid) in promoting plant growth, yet plants require greater concentrations of PAA to elicit the same physiological responses. Here we show that normalized PAA treatment results in the differential expression of a unique list of genes, suggesting that plants can respond differently to the two auxins. This is further explored in endodermal barrier regulation where the two auxins invoke striking differences in the deposition patterns of suberin. We further show that auxin acts antagonistically on Casparian strip (CS) formation as it can circumvent the CS transcriptional machinery to repress CS related genes. Additionally, altered suberin biosynthesis reduces endogenous levels of PAA and CS deficiency represses the biosynthesis of IAA and the levels of both auxins. These findings implicate auxin as a regulator of endodermal barrier formation and highlight a novel role for PAA in root development and differentiation.

Development and Cell Biology of the Blood-Brain Barrier

2019 ◽  
Vol 35 (1) ◽  
pp. 591-613 ◽  
Author(s):  
Urs H. Langen ◽  
Swathi Ayloo ◽  
Chenghua Gu
Keyword(s):  
Blood Brain Barrier ◽  
Brain Function ◽  
Cell Biology ◽  
Brain Barrier ◽  
Cns Drug Delivery ◽  
Blood Brain ◽  
Barrier Formation ◽  
The Central Nervous System ◽  
Barrier Regulation ◽  
And Function

The vertebrate vasculature displays high organotypic specialization, with the structure and function of blood vessels catering to the specific needs of each tissue. A unique feature of the central nervous system (CNS) vasculature is the blood-brain barrier (BBB). The BBB regulates substance influx and efflux to maintain a homeostatic environment for proper brain function. Here, we review the development and cell biology of the BBB, focusing on the cellular and molecular regulation of barrier formation and the maintenance of the BBB through adulthood. We summarize unique features of CNS endothelial cells and highlight recent progress in and general principles of barrier regulation. Finally, we illustrate why a mechanistic understanding of the development and maintenance of the BBB could provide novel therapeutic opportunities for CNS drug delivery.

scholarly journals Ruminal bioshynthesis of aromatic amino acids from arylacetic acids, glucose, shikimic acid and phenol

1974 ◽  
Vol 31 (3) ◽  
pp. 357-365 ◽  
Author(s):  
S. Kristensen
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Phenylacetic Acid ◽  
Shikimic Acid ◽  
Aromatic Amino Acids ◽  
Hydroxyphenylacetic Acid ◽  
Arylacetic Acids ◽  
First Time ◽  
Indole 3 Acetic Acid

1. Ruminal metabolism of labelled phenylacetic acid, 4-hydroxyphenylacetic acid, indole-3-acetic acid, glucose, shikimic acid, phenol, and serine was studied in vitro by short-term incubation with special reference to incorporation rates into aromatic amino acids.2. Earlier reports on reductive carboxylation of phenylacetic acid and indole-3-acetic acid in the rumen were confirmed and the formation of tyrosine from 4-hydroxyphenylacetic acid was demonstrated for the first time.3. The amount of phenylalanine synthesized from phenylacetic acid was estimated to be 2 mg/1 rumen contents per 24 h, whereas the amount synthesized from glucose might be eight times as great, depending on diet.4. Shikimic acid was a poor precursor of the aromatic amino acids, presumably owing to its slow entry into rumen bacteria.5. A slow conversion of phenol into tyrosine was observed.

scholarly journals UDP-glucosyltransferase UGT84B1 regulates the levels of indole-3-acetic acid and phenylacetic acid in Arabidopsis

2020 ◽  
Vol 532 (2) ◽  
pp. 244-250
Author(s):  
Yuki Aoi ◽  
Hayao Hira ◽  
Yuya Hayakawa ◽  
Hongquan Liu ◽  
Kosuke Fukui ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Phenylacetic Acid ◽  
Indole 3 Acetic Acid

A peptide hormone required for Casparian strip diffusion barrier formation in Arabidopsis roots

Science ◽  
2017 ◽  
Vol 355 (6322) ◽  
pp. 284-286 ◽  
Author(s):  
Takuya Nakayama ◽  
Hidefumi Shinohara ◽  
Mina Tanaka ◽  
Koki Baba ◽  
Mari Ogawa-Ohnishi ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Peptide Hormone ◽  
Casparian Strip ◽  
Barrier Formation

scholarly journals Characterizing the transcriptional expression and in situ localization of the Dnmt2 gene in Drosophila willistoni

2019 ◽  
Author(s):  
Gilberto Cavalheiro Vieira ◽  
Marícia Fantinel D’Ávila ◽  
Rebeca Zanini ◽  
Pâmela Silva de Oliveira ◽  
Maríndia Deprá ◽  
...  
Keyword(s):  
Dna Methyltransferase ◽  
Biological Function ◽  
Telomeric Region ◽  
Stages Of Development ◽  
Evolutionary Patterns ◽  
Early Stages ◽  
Molecular Features ◽  
Invertebrate Development ◽  
Development And Differentiation

Abstract Background: Organisms that have only the DNA methyltransferase 2 (Dnmt2) to mediate the DNA methylation are called "Dnmt2-only" and they have been investigated in recent surveys. Drosophila is one of the “Dnmt2-only” organisms and is also an ideal model for Dnmt2 research. However, the biological function of the Dnmt2 protein is still uncertain. Some studies have pointed to a putative role during the early stages of invertebrate development. In this work, we present our findings on the Dnmt2 expression in D. willistoni, a neotropical species of large ecological versatility and peculiar molecular features. Results: By RT-PCR and in situ hybridization we demonstrate here the presence of transcripts not only in the early stages of development, but also during the oogenesis. Using qPCR analysis, we verify that Dnmt2 transcription level is higher during early stages of development, though transcription levels are subtly higher in D. willistoni adults than in D. melanogaster levels found in previous studies. We also mapped the Dnmt2 on the IIL chromosome arm (Muller’s B element) of D. willistoni, near at the end of the singular telomeric region. Conclusions: Our findings give insights on the possible biological function of Dnmt2-related processes associated with the development and differentiation of oocytes since germinative tissue formation seems to require a higher expression of Dnmt2. The Dnmt2 localization in the subtelomeric region brings up a series of issues that involve the peculiar characteristics of D. willistoni Dnmt2 enzyme, like evolutionary patterns and the epigenetic phenomena of sex-specific methylation.

scholarly journals Two Receptor-Like Kinases Required For Arabidopsis Endodermal Root Organisation Shape The Rhizosphere Microbiome

2019 ◽  
Author(s):  
Julius Durr ◽  
Guilhem Reyt ◽  
Stijn Spaepen ◽  
Sally Hilton ◽  
Cathal Meehan ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Subcellular Localisation ◽  
Loss Of Function ◽  
Microbial Composition ◽  
Microbiome Composition ◽  
Casparian Strip ◽  
Receptor Like Kinase ◽  
Membrane Bound ◽  
Root Endodermis ◽  
Lignin Deposition

AbstractThe Casparian Strip (CS) constitutes a physical diffusion barrier to water and nutrients in plant roots, and is formed by the polar deposition of lignin polymer in the endodermis. This precise pattern of lignin deposition is thought to be mediated by the scaffolding activity of membrane-bound Casparian Strip domain proteins (CASPs). However, we show that endodermis-specific receptor-like kinase 1 (ERK1) and ROP Binding Kinase1 (RBK1) are also involved in this intricate process, with the former playing an essential role both in the localization of CASP1 and in lignin deposition. We further characterised ERK1 and determined its subcellular localisation in the cytoplasm and nucleus of the endodermis, as well as provide evidence for its involvement in a signalling pathway together with the circadian clock regulator, Time for Coffee (TIC). We also show that disruption to CS organisation and increased suberisation in the endodermis due to loss of function of either ERK1 or TIC collectively leads to an altered root microbiome composition. Thus, our work reveals additional players in the complex cascade of signalling events operating in the root endodermis to establish both the CS diffusion barrier and the microbial composition of the rhizosphere.

scholarly journals Synthesis of three major auxins from glucose in EngineeredEscherichia coli

2018 ◽  
Author(s):  
Daoyi Guo ◽  
Lihua Zhang ◽  
Sijia Kong ◽  
Zhijie Liu ◽  
Xu Chu ◽  
...  
Keyword(s):  
Plant Growth ◽  
Phenylacetic Acid ◽  
De Novo ◽  
Shikimate Pathway ◽  
Aromatic Amino Acids ◽  
Plant Growth And Development ◽  
E Coli ◽  
Naturally Occurring ◽  
Hydroxyphenylacetic Acid ◽  
Indole 3 Acetic Acid

ABSTRACTIndole-3-acetic acid (IAA) is considered the most common and important naturally occurring auxin in plants and a major regulator of plant growth and development. In addition, phenylacetic acid (PAA) and 4-hydroxyphenylacetic acid (4HPA) can also play a role as auxin in some plants. In recent years, several microbes have been metabolically engineered to produce IAA from L-tryptophan. In this study, we showed that aminotransferasearo8and decarboxylasekdcfromSaccharomyces cerevisiae, and aldehyde dehydrogenasealdHfromEscherichia colihave broad substrate ranges and can catalyze the conversion of three kinds of aromatic amino acids (L-tryptophan, L-tyrosine or L-phenylalanine) to the corresponding IAA, 4HPA and PAA. Subsequently, three de novo biosynthetic pathways for the production of IAA, PAA and 4HPA from glucose were constructed inE. colithrough strengthening the shikimate pathway. This study described here shows the way for the development of agricultural microorganism for biosynthesis of plant auxin and promoting plant growth in the future.

scholarly journals Fungal auxin is a quorum-based modulator of blast disease severity

2021 ◽  
Author(s):  
Lihong Dong ◽  
Qing Shen ◽  
Cheng-Yen Chen ◽  
Lizheng Shen ◽  
Fan Yang ◽  
...  
Keyword(s):  
Rice Blast ◽  
Biological Function ◽  
Pyruvate Decarboxylase ◽  
Microbial Pathogens ◽  
Blast Disease ◽  
Dependent Manner ◽  
Acid Biosynthesis ◽  
Chemical Inhibition ◽  
Dose Dependent ◽  
Indole 3 Acetic Acid

Auxin is an important phytohormone regulating plant growth and development, and can also be produced by microbial pathogens including the rice-blast fungus Magnaporthe oryzae. However, the detailed biosynthesis pathway, biological function(s), and cellular distribution of such fungal auxin in M. oryzae remain largely unknown. Here, we report a sequential accumulation of intrinsic auxin in the three conidial cells, the infection structure (appressorium), and the invasive hyphae in M. oryzae. Such fungus-derived auxin was also secreted out and perceived by the host plants. A mitochondria-associated Indole-3-pyruvate decarboxylase, Ipd1, is essential for auxin/Indole-3-acetic acid biosynthesis in M. oryzae. The ipd1 mutant was defective in pathogenicity whereas overexpression of IPD1 led to enhanced virulence in rice. Chemical inhibition of fungal IAA biosynthesis, or its increase via external supplementation decreased or increased the severity of blast disease, respectively, in a dose-dependent manner. Furthermore, the IAA produced and secreted by M. oryzae governed the incidence and severity of blast disease in a quorum-dependent manner. Appressorium formation, conidial cell death critical for appressorium function, and the transcription of infection-related genes, MPG1 and INV1, directly correlated with cell density and/or IAA levels within the conidial population at the early stages of pathogenic development. Overall, our study revealed that the severity of blast disease is regulated via quorum sensing with intrinsic IAA serving as an associated signal transducer in rice blast.

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