Overexpression of the CBF2 transcriptional activator in Arabidopsis counteracts hormone activation of leaf senescence

Michal Sharabi-Schwager, Alon Samach, Ron Porat*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

CBF1-3 (C-repeat binding factors) are transcriptional activators governing plant responses to low temperatures. Overexpression of CBF1-3 genes enhances plant frost tolerance, but also causes various pleiotropic effects regarding plant growth and development, mainly growth retardation, and delay of flowering and senescence. In a recent study, we reported that overexpression of CBF2 suppressed leaf senescence induced by the stress hormone ethylene. Here we show that overexpression of CBF2 also suppressed chlorophyll breakdown and leaf senescence induced by the phytohormones abscisic acid (ABA), salicylic acid (SA) and methyl jasmonate (MeJA), which indicates its broader role in suppressing hormone-induced leaf senescence. As previously reported for ethylene, the observed decrease in responsiveness to ABA in CBF2-overexpressing plants was specific to leaf senescence, since other responses to ABA were similar to those of wild-type plants. Transcript profiling analysis of hormone metabolism and responsive genes revealed that overexpression of CBF2 induced expression of ABAbiosynthesis and ABA-responsive genes and suppressed SA- and JA-related genes. Overall, in light of the adverse effects of CBF2 on ABA metabolism and responsiveness, on the one hand, and SA and JA metabolism and responsiveness, on the other hand, we conclude that overexpression of CBF2 suppresses hormone-induced leaf senescence by directly counteracting the hormone effects on leaf senescence and not by general suppression of their synthesis or signal transduction pathways.

Original languageAmerican English
Pages (from-to)296-299
Number of pages4
JournalPlant Signaling and Behavior
Volume5
Issue number3
DOIs
StatePublished - 2010

Keywords

  • Abscisic acid
  • Arabidopsis
  • CBF2
  • Jasmonic acid
  • Salicylic acid
  • Senescence

Fingerprint

Dive into the research topics of 'Overexpression of the CBF2 transcriptional activator in Arabidopsis counteracts hormone activation of leaf senescence'. Together they form a unique fingerprint.

Cite this