scholarly journals Auxin-induced developmental patterns in Brassica juncea embryos

Development ◽  
1998 ◽  
Vol 125 (5) ◽  
pp. 879-887 ◽  
Author(s):  
K. Hadfi ◽  
V. Speth ◽  
G. Neuhaus
Keyword(s):  
Brassica Juncea ◽  
Auxin Transport ◽  
Developmental Patterns ◽  
Globular Embryos ◽  
Auxin Distribution ◽  
Wide Range ◽  
Auxin Transport Inhibitor ◽  
Indole 3 Acetic Acid ◽  
Chlorophenoxyisobutyric Acid

To investigate the mechanism of auxin action during pattern formation in dicot embryos, we tested the effects of the natural auxin indole-3-acetic acid (IAA), the auxin transport inhibitor N-(1-naphthyl)thalamic acid (NPA) and the antiauxin p-chlorophenoxyisobutyric acid (PCIB). In vitro treatments of isolated zygotic Brassica juncea embryos with these substances led to a wide range of morphogenetic alterations. Treatment of globular embryos with exogenous auxin (10-40 microM) either completely inhibited morphogenesis, resulting in ball-shaped embryos, or caused the development of egg- and cucumber-shaped embryos, which only consisted of a shortened hypocotyl without any apical structures. Axis duplication was observed sometimes after inhibition of auxin transport in globular embryos, and led to the development of twin embryos. During the transition from globular to heart stage, changes in auxin distribution or activity frequently caused the development of either split-collar or collar-cotyledons. Antiauxin inhibited cotyledon growth, leading to embryos with single or no cotyledons, or inhibited the development of the hypocotyl and the radicle. Inhibition of auxin transport in transition embryos sometimes led to axis broadening, which resulted in the development of two radicles. The described changes in embryo shapes represent arrests in different auxin-regulated developmental steps and phenocopy some Arabidopsis morphogenetic mutants.

Effects of indole-3-acetic acid and auxin transport inhibitor on auxin distribution and development of peanut at pegging stage

2013 ◽  
Vol 162 ◽  
pp. 76-81 ◽  
Author(s):  
Qiong Peng ◽  
Huiqun Wang ◽  
Jianhua Tong ◽  
Mohammed Humayun Kabir ◽  
Zhigang Huang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Auxin Transport ◽  
Auxin Distribution ◽  
Transport Inhibitor ◽  
Auxin Transport Inhibitor ◽  
Indole 3 Acetic Acid

scholarly journals The ectopic expression of Arabidopsis glucosyltransferase UGT74D1 affects leaf positioning through modulating indole-3-acetic acid homeostasis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shanghui Jin ◽  
Bingkai Hou ◽  
Guizhi Zhang
Keyword(s):  
Acetic Acid ◽  
Ectopic Expression ◽  
Leaf Angle ◽  
Kinase Substrate ◽  
Auxin Distribution ◽  
Leaf Tissues ◽  
Photosynthesis Efficiency ◽  
Indole 3 Acetic Acid

AbstractLeaf angle is an important agronomic trait affecting photosynthesis efficiency and crop yield. Although the mechanisms involved in the leaf angle control are intensively studied in monocots, factors contribute to the leaf angle in dicots are largely unknown. In this article, we explored the physiological roles of an Arabidopsis glucosyltransferase, UGT74D1, which have been proved to be indole-3-acetic acid (IAA) glucosyltransferase in vitro. We found that UGT74D1 possessed the enzymatic activity toward IAA glucosylation in vivo and its expression was induced by auxins. The ectopically expressed UGT74D1 obviously reduced the leaf angle with an altered IAA level, auxin distribution and cell size in leaf tissues. The expression of several key genes involved in the leaf shaping and leaf positioning, including PHYTOCHROME KINASE SUBSTRATE (PKS) genes and TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) genes, were dramatically changed by ectopic expression of UGT74D1. In addition, clear transcription changes of YUCCA genes and other auxin related genes can be observed in overexpression lines. Taken together, our data indicate that glucosyltransferase UGT74D1 could affect leaf positioning through modulating auxin homeostasis and regulating transcription of PKS and TCP genes, suggesting a potential new role of UGT74D1 in regulation of leaf angle in dicot Arabidopsis.

scholarly journals Identification and Expression Analysis of the PIN and AUX/LAX Gene Families in Ramie (Boehmeria nivea L. Gaud)

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 435 ◽  
Author(s):  
Yaning Bao ◽  
Xing Huang ◽  
Muzammal Rehman ◽  
Yunhe Wang ◽  
Bo Wang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Auxin Transport ◽  
Expression Patterns ◽  
Gene Families ◽  
Ramie Fiber ◽  
Biological Functions ◽  
Qrt Pcr ◽  
Boehmeria Nivea ◽  
Auxin Distribution ◽  
Indole 3 Acetic Acid

Auxin regulates diverse aspects of growth and development. Furthermore, polar auxin transport, which is mediated by the PIN-FORMED (PIN) and AUXIN1/LIKE-AUX (AUX/LAX) proteins, plays a crucial role in auxin distribution. In this study, six PIN and four AUX/LAX genes were identified in ramie (Boehmeria nivea L.). We used qRT-PCR to characterize and analyze the two gene families, including phylogenetic relationships, intron/exon structures, cis-elements, subcellular localization, and the expression patterns in different tissues. The expression of these genes in response to indole-3-acetic acid (IAA) treatment and drought stress was also assessed; the results indicate that most of the BnAUX/LAX and BnPIN genes were regulated as a result of IAA treatment and drought stress. Our study provides insights into ramie auxin transporters and lays the foundation for further analysis of their biological functions in ramie fiber development and adaptation to environmental stresses.

scholarly journals Activation of Big Grain1 significantly improves grain size by regulating auxin transport in rice

2015 ◽  
Vol 112 (35) ◽  
pp. 11102-11107 ◽  
Author(s):  
Linchuan Liu ◽  
Hongning Tong ◽  
Yunhua Xiao ◽  
Ronghui Che ◽  
Fan Xu ◽  
...  
Keyword(s):  
Grain Size ◽  
Auxin Transport ◽  
Vascular Tissue ◽  
Plant Biomass ◽  
Key Factors ◽  
Auxin Distribution ◽  
New Strategy ◽  
Dna Insertion ◽  
Auxin Transport Inhibitor ◽  
Naphthylphthalamic Acid

Grain size is one of the key factors determining grain yield. However, it remains largely unknown how grain size is regulated by developmental signals. Here, we report the identification and characterization of a dominant mutant big grain1 (Bg1-D) that shows an extra-large grain phenotype from our rice T-DNA insertion population. Overexpression of BG1 leads to significantly increased grain size, and the severe lines exhibit obviously perturbed gravitropism. In addition, the mutant has increased sensitivities to both auxin and N-1-naphthylphthalamic acid, an auxin transport inhibitor, whereas knockdown of BG1 results in decreased sensitivities and smaller grains. Moreover, BG1 is specifically induced by auxin treatment, preferentially expresses in the vascular tissue of culms and young panicles, and encodes a novel membrane-localized protein, strongly suggesting its role in regulating auxin transport. Consistent with this finding, the mutant has increased auxin basipetal transport and altered auxin distribution, whereas the knockdown plants have decreased auxin transport. Manipulation of BG1 in both rice and Arabidopsis can enhance plant biomass, seed weight, and yield. Taking these data together, we identify a novel positive regulator of auxin response and transport in a crop plant and demonstrate its role in regulating grain size, thus illuminating a new strategy to improve plant productivity.

Effect of an auxin transport inhibitor on aggregation and attachment processes during ectomycorrhiza formation between Laccaria bicolor S238N and Picea abies

2001 ◽  
Vol 79 (10) ◽  
pp. 1152-1160
Author(s):  
Ana Rincón ◽  
Joëlle Gérard ◽  
Jean Dexheimer ◽  
François Le Tacon
Keyword(s):  
Picea Abies ◽  
Auxin Transport ◽  
Protein Structures ◽  
Laccaria Bicolor ◽  
Transport Inhibitor ◽  
Transmission Electron ◽  
Auxin Transport Inhibitor ◽  
Host Effect ◽  
Indole 3 Acetic Acid ◽  
Attachment Process

Transmission electron microscopy observations performed with cytochemical stains to detect polysaccharides and cysteine-rich proteins have been done to study the effect of an auxin transport inhibitor (2,3,5-triiodobenzoic acid, TIBA) on Laccaria bicolor (Marie) Orton. hypha attachment and aggregation during mycorrhiza formation in Picea abies (L.) Karst. roots. When the two partners were growing separately without any exchange of information, TIBA did not affect the cell wall's polysaccharide or protein structures, which could play a role in the aggregation or attachment process. The presence of the host strongly increased the production of fungal polysaccharide fibrils, allowing hypha aggregation and attachment with the roots. TIBA inhibited this host effect. Thus, we can hypothesize that TIBA, by preventing fungal indole-3-acetic acid (IAA) transport towards the root, inhibited the production or the efflux of host elicitors responsible for the increase of fungal polysaccharide fibril production. However, we cannot exclude that TIBA had other effects than inhibiting fungal IAA transport.Key words: ectomycorrhizas, auxin transport inhibitor, polysaccharide fibrils.

scholarly journals Tomato ATP-Binding Cassette Transporter SlABCB4 Is Involved in Auxin Transport in the Developing Fruit

Plants ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 65 ◽  
Author(s):  
Peter Ofori ◽  
Markus Geisler ◽  
Martin di Donato ◽  
Hao Pengchao ◽  
Shungo Otagaki ◽  
...  
Keyword(s):  
Fruit Development ◽  
Auxin Transport ◽  
Tomato Fruit ◽  
Multi Drug Resistance ◽  
Fleshy Fruit ◽  
Atp Binding ◽  
Resistance Proteins ◽  
Auxin Distribution ◽  
Wide Range ◽  
Atp Binding Cassette

Plant ATP binding cassette (ABC) transporters are membrane proteins that are important for transporting a wide range of compounds, including secondary metabolites and phytohormones. In Arabidopsis, some members of the ABCB subfamily of ABC transporter, also known as Multi-Drug Resistance proteins (MDRs), have been implicated in auxin transport. However, reports on the roles of the auxin-mediated ABCBs in fleshy fruit development are rare. Here, we present that SlABCB4, a member of the tomato ABCB subfamily, transports auxin in the developing fruit of tomato. Transient expression of SlABCB4-GFP fusion proteins in tobacco cells showed plasma membrane localization. The transport activity of SlABCB4, expressed in Nicotiana benthamiana protoplasts, revealed substrate specificity for indole-3-acetic acid export. Gene expression analysis of SlABCB4 revealed high expression levels at the early stages of fruit development. Therefore, SlABCB4 is considered to facilitate auxin distribution in tomato fruit, which is important for tomato fruit development.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

In Vitro Clot Lysis as a Potential Indicator of Thrombus Resistance to Fibrinolysis – Study in Healthy Subjects and Correlation with Blood Fibrinolytic Parameters

1997 ◽  
Vol 77 (04) ◽  
pp. 725-729 ◽  
Author(s):  
Mario Colucci ◽  
Silvia Scopece ◽  
Antonio V Gelato ◽  
Donato Dimonte ◽  
Nicola Semeraro
Keyword(s):  
Plasminogen Activator ◽  
Clot Lysis ◽  
Individual Response ◽  
Plasminogen Activator Inhibitor 1 ◽  
Autologous Plasma ◽  
Wide Range ◽  
Blood Clots ◽  
Physiological Variations ◽  
Pai 1

SummaryUsing an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37° C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-anti-plasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p <0.001) and age (p <0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-ginduced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy.

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