Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Many ways to grow

25.05.2009
Environmental conditions may determine which particular process plants will use to build an essential hormone

For the better part of a century, scientists have recognized indole-3-acetic acid (IAA), one of several hormones known as auxins, as one of the most important drivers of plant growth and development. However, it remains unclear exactly how IAA is synthesized. Previous research has identified at least four different enzymatic ‘assembly lines’ that may be involved in its production, and each of these pathways generates chemical compounds that are potential precursors to IAA, as well as a number of other biologically important molecules involved in protecting plants against predators and pathogens.

In the thale cress plant, Arabidopsis thaliana, indole-3-actaldoxime (IAOx) is thought to represent a likely intermediate compound in IAA production via two of these candidate pathways, CYP79B and YUC. In order to clarify which of these contribute primarily to production of IAOx and IAA, Hiroyuki Kasahara of the RIKEN Plant Science Center in Yokohama and colleagues generated several mutant Arabidopsis strains in which key enzymes in either pathway had been ablated.

From the data, the team consistently identified an exclusive role for the CYP79B pathway in IAOx production and—by extension—IAA synthesis, and demonstrated no effect on levels of either compound resulting from interference with YUC-associated enzymes1. They also identified two compounds, indole-3-acetamide and indole-3-acetonitrile, as likely intermediates in the conversion of IAOx to IAA. Many plant species, including tobacco and rice, lack the CYP79B pathway altogether and do not produce detectable IAOx. However, these plants do produce these other IAA intermediates, suggesting the existence of yet-unidentified, parallel biosynthetic pathways in these species.

These findings indicate the need for a considerable reorganization of existing models of plant hormone synthesis. “Before this research, three proposed pathways were thought to converge at IAOx or its metabolites,” says Kasahara. “We have clearly separated these pathways.” Interestingly, their data also revealed that even in Arabidopsis, CYP79B does not represent the primary pathway of IAA production; instead, it is simply one of several that appear to contribute under different, specific conditions—in this case, cultivation at higher than room temperature.

Other non-IAOx biosynthetic pathways appear to be common to most plant species and Kasahara and colleagues now hope to clarify their independent contributions to overall IAA production. “We do not know why plants have so many biosynthetic pathways for IAA,” he says. “Here we showed that the IAOx pathway contributes to IAA generation under high temperature conditions, and now we are studying the physiological roles of other IAA biosynthetic pathways.”

Reference

1. Sugawara, S., Hishiyama, S., Jikumaru, Y., Hanada, A., Nishimura, T., Koshiba, T., Zhao, Y., Kamiya, Y. & Kasahara, H. Biochemical analyses of indole-3-acetaldoxime-dependent auxin biosynthesis in Arabidopsis. Proceedings of the National Academy of Sciences USA 106, 5430–5435 (2009).

The corresponding author for this highlight is based at the RIKEN Growth Regulation Research Team

Saeko Okada | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/research/705/
http://www.researchsea.com

More articles from Life Sciences:

nachricht New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln

nachricht A blue stoplight to prevent runaway photosynthesis
27.09.2016 | National Institute for Basic Biology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: Neuer Schalter entscheidet zwischen Reparatur und Zelltod

Eine der wichtigsten Entscheidungen, die eine Zelle zu treffen hat, ist eine Frage von Leben und Tod: kann ein Schaden repariert werden oder ist es sinnvoller zellulären Selbstmord zu begehen um weitere Schädigung zu verhindern? In einer Kaskade eines bisher wenig verstandenen Signalweges konnten Forscher des Exzellenzclusters für Alternsforschung CECAD an der Universität zu Köln ein Protein identifizieren (UFD-2), das eine Schlüsselrolle in dem Prozess einnimmt. Die Ergebnisse wurden in der Fachzeitschrift Nature Structural & Molecular Biology veröffentlicht.

Die genetische Information einer jeden Zelle liegt in ihrer Sequenz der DNA-Doppelhelix. Doppelstrangbrüche der DNA, die durch Strahlung hervorgerufen werden...

Im Focus: Forscher entwickeln quantenphotonischen Schaltkreis mit elektrischer Lichtquelle

Optische Quantenrechner könnten die Computertechnologie revolutionieren. Forschern um Wolfram Pernice von der Westfälischen Wilhelms-Universität Münster sowie Ralph Krupke, Manfred Kappes und Carsten Rockstuhl vom Karlsruher Institut für Technologie ist es nun gelungen, einen quantenoptischen Versuchsaufbau auf einem Chip zu platzieren. Damit haben sie eine Voraussetzung erfüllt, um photonische Schaltkreise für optische Quantencomputer nutzbar machen zu können.

Ob für eine abhörsichere Datenverschlüsselung, die ultraschnelle Berechnung riesiger Datenmengen oder die sogenannte Quantensimulation, mit der hochkomplexe...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: Quantenboost für künstliche Intelligenz

Intelligente Maschinen, die selbständig lernen, gelten als Zukunftstrend. Forscher der Universität Innsbruck und des Joint Quantum Institute in Maryland, USA, loten nun in der Fachzeitschrift Physical Review Letters aus, wie Quantentechnologien dabei helfen können, die Methoden des maschinellen Lernens weiter zu verbessern.

In selbstfahrenden Autos, IBM's Watson oder Google's AlphaGo sind Computerprogramme am Werk, die aus Erfahrungen lernen können. Solche Maschinen werden im Zuge...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

European Health Forum Gastein 2016 beginnt

28.09.2016 | Veranstaltungen

Compliance im Fokus - CLARIUS.LEGAL auf der Dialog on Tour in Hamburg

28.09.2016 | Veranstaltungen

Laser für Neurochirurgie und Biofabrikation - LaserForum 2016 thematisiert Medizintechnik

27.09.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Wald in Inventur: Unbemannte Helikopter zur Datenerhebung

28.09.2016 | Informationstechnologie

Besserer Schutz vor Gebärmutterhalskrebs

28.09.2016 | Biowissenschaften Chemie

Carsharing-Software: Störungen auf der anderen Seite des Globus erkennen

28.09.2016 | Informationstechnologie