Next Article in Journal
A Substantial Fraction of Barley (Hordeum vulgare L.) Low Phytic Acid Mutations Have Little or No Effect on Yield across Diverse Production Environments
Next Article in Special Issue
Functions of Nitric Oxide (NO) in Roots during Development and under Adverse Stress Conditions
Previous Article in Journal
Overexpression of a Gene Involved in Phytic Acid Biosynthesis Substantially Increases Phytic Acid and Total Phosphorus in Rice Seeds
Article Menu

Export Article

Open AccessArticle
Plants 2015, 4(2), 209-224; doi:10.3390/plants4020209

Multiple Autoregulation of Nodulation (AON) Signals Identified through Split Root Analysis of Medicago truncatula sunn and rdn1 Mutants

1
Department of Genetics & Biochemistry, Clemson University, Clemson, SC 29634, USA
2
Department of Mathematical Sciences, Clemson University, Clemson, SC 29634, USA
3
Department of Genetics & Biochemistry, Clemson University, Clemson, SC 29634, USA
Currently address: Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
*
Author to whom correspondence should be addressed.
Academic Editor: Rujin Chen
Received: 4 March 2015 / Revised: 9 April 2015 / Accepted: 16 April 2015 / Published: 27 April 2015
(This article belongs to the Special Issue Plant Root Development)
View Full-Text   |   Download PDF [939 KB, uploaded 27 April 2015]   |  

Abstract

Nodulation is energetically costly to the host: legumes balance the nitrogen demand with the energy expense by limiting the number of nodules through long-distance signaling. A split root system was used to investigate systemic autoregulation of nodulation (AON) in Medicago truncatula and the role of the AON genes RDN1 and SUNN in the regulatory circuit. Developing nodule primordia did not trigger AON in plants carrying mutations in RDN1 and SUNN genes, while wild type plants had fully induced AON within three days. However, despite lacking an early suppression response, AON mutants suppressed nodulation when roots were inoculated 10 days or more apart, correlated with the maturation of nitrogen fixing nodules. In addition to correlation between nitrogen fixation and suppression of nodulation, suppression by extreme nutrient stress was also observed in all genotypes and may be a component of the observed response due to the conditions of the assay. These results suggest there is more than one systemic regulatory circuit controlling nodulation in M. truncatula. While both signals are present in wild type plants, the second signal can only be observed in plants lacking the early repression (AON mutants). RDN1 and SUNN are not essential for response to the later signal. View Full-Text
Keywords: autoregulation of nodulation; Medicago truncatula; split-root analysis; nitrogen; RDN1; SUNN autoregulation of nodulation; Medicago truncatula; split-root analysis; nitrogen; RDN1; SUNN
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Kassaw, T.; Jr., W.B.; Frugoli, J. Multiple Autoregulation of Nodulation (AON) Signals Identified through Split Root Analysis of Medicago truncatula sunn and rdn1 Mutants. Plants 2015, 4, 209-224.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Plants EISSN 2223-7747 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top