The tomato brassinosteroid receptor BRI1 increases binding of systemin to tobacco plasma membranes, but is not involved in systemin signaling

The tomato brassinosteroid receptor BRI1 increases binding of systemin to tobacco plasma... The tomato wound signal systemin is perceived by a specific high-affinity, saturable, and reversible cell surface receptor. This receptor was identified as the receptor-like kinase SR160, which turned out to be identical to the brassinosteroid receptor BRI1. Recently, it has been shown that the tomato bri1 null mutant cu3 is as sensitive to systemin as wild type plants. Here we explored these contradictory findings by studying the responses of tobacco plants (Nicotiana tabacum) to systemin. A fluorescently-labeled systemin analog bound specifically to plasma membranes of tobacco suspension-cultured cells that expressed the tomato BRI1-FLAG transgene, but not to wild type tobacco cells. On the other hand, signaling responses to systemin, such as activation of mitogen-activated protein kinases and medium alkalinization, were neither increased in BRI1-FLAG-overexpressing tobacco cells nor decreased in BRI1-silenced cells as compared to levels in untransformed control cells. Furthermore, in transgenic tobacco plants BRI1-FLAG became phosphorylated on threonine residues in response to brassinolide application, but not in response to systemin. When BRI1 transcript levels were reduced by virus-induced gene silencing in tomato plants, the silenced plants displayed a phenotype characteristic of bri1 mutants. However, their response to overexpression of the Prosystemin transgene was the same as in control plants. Taken together, our data suggest that BRI1 can function as a systemin binding protein, but that binding of the ligand does not transduce the signal into the cell. This unusual behavior and the nature of the elusive systemin receptor will be discussed. Plant Molecular Biology Springer Journals

The tomato brassinosteroid receptor BRI1 increases binding of systemin to tobacco plasma membranes, but is not involved in systemin signaling

Loading next page...
Springer Netherlands
Copyright © 2009 by Springer Science+Business Media B.V.
Life Sciences; Plant Pathology; Biochemistry, general; Plant Sciences
Publisher site
See Article on Publisher Site


You’re reading a free preview. Subscribe to read the entire article.

DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches


Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.



billed annually
Start Free Trial

14-day Free Trial