U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Key Transcription Factor in Plant Senescence Regulates Chlorophyll Degradation and Abscisic Acid Biosynthesis
Published: December 16, 2014
Posted: March 12, 2015

The timing of plant senescence can have a significant impact on the yield and quality of bioenergy feedstocks. Therefore, more knowledge is welcome on the regulation of and genes involved in plant senescence. Department of Energy BioEnergy Science Center researchers have gained new understanding of senescence in the experimentally tractable plant Arabidopsis thaliana. Chlorophyll degradation is an important part of leaf senescence, but the underlying regulatory mechanisms are largely unknown. The researchers found that the dark, excised leaves of an Arabidopsis thaliana transcription factor mutant (nap) exhibit a stay-green phenotype. This finding is correlated with lower transcript levels of several known chlorophyll degradation genes, and higher chlorophyll retention than the wild type during dark-induced senescence. Several plant hormones play a role in senescence; one of them, abscisic acid (ABA), is known to induce leaf senescence. Transcriptome coexpression analysis revealed that ABA metabolism/signaling genes were disproportionately represented among those positively correlated with expression of the NAP transcription factor. To further investigate ABA’s role in senescence and the stay-green phenotype, ABA was applied exogenously to excised NAP mutant leaves. Transcript levels of several chlorophyll degradation enzymes increased and the stay-green phenotype was suppressed. Collectively, the results show that the NAP transcription factor promotes chlorophyll degradation by enhancing transcription of the ABA biosynthesis gene, AAO3, which leads to increased levels of the senescence-inducing hormone ABA. This new understanding will be helpful in improving yields of bioenergy feedstocks by controlling senescence.

Reference: Yang, J., E. Worley, and M. Udvard. 2014. “A NAP-AA03 Regulatory Module Promotes Chlorophyll Degradation via ABA Biosynthesis in Arabidopsis leaves,” The Plant Cell 26, 4862–74. DOI: 10.1105/tpc.114.133769. (Reference link)

Contact: Kent Peters, SC-23.2, (301) 903-5549
Topic Areas:

  • Research Area: Genomic Analysis and Systems Biology
  • Research Area: Plant Systems and Feedstocks, Plant-Microbe Interactions
  • Research Area: Sustainable Biofuels and Bioproducts
  • Research Area: DOE Bioenergy Research Centers (BRC)

Division: SC-23.2 Biological Systems Science Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)