Plants, like all higher eukaryotes, must control the onset and spread of cell death. Plant biology is replete with examples of developmentally controlled programmed cell death (POD). Additionally, a specialized form of POD in plants, termed the Hypersensitive Response (HR) is tightly correlated with successful recognition of, and response to, pathogen attack. Thus, the HR is potentially an important part of the plant innate immune response. It is, however, unclear what causal role HR plays in stopping pathogen ingress, or whether HR is the consequence of the plant defense response that does kill the pathogen. It is equally unclear whether the genetic control of HR is mechanistically related to, or distinct from, the mechanisms that control plant PCD during development. Additionally, while much is known about the molecular mechanisms of PCD control in animals, essentially nothing is known in plants. This proposal is focused on using Arabidopsis as a genetic model with which to understand the control of HR as an easily definable model for POD in plants. The Arabidopsis genome is fully sequenced and there is little molecular evidence for conservation of key regulators of animal POD at the sequence level. We were among the first to recognize the use of Arabidopsis to genetically dissect cell death control and have made significant contributions to the field. We identified and analyzed a series of mutants that misregulate HR-like cell death in the absence of pathogen. We cloned three key HR regulators all belonging to one gene family: LSD1 and the related genes LOL 1 (LSD One Like 1) and LOL2. We also demonstrated that LSD1 interacts with two classes of transcriptional regulators, that these proteins have biological functions in HA, and that they interact with LSD1 in viva. Based on this previous work, and on the progress reported below, the topics for the Specific Aims, using both forward and reverse genetics, and biochemistry, are: 1. The Arabidopsis LSD1 protein: Control of cell death propagation. 2. isdi signal transduction: Genetic characterization of extragenic isdi suppressors. 3. Molecular homologues of LSD1 also control cell death. 4. The interplay between Isd1 rcd and balances of ROl, NO and SA.
| Coll, N S; Smidler, A; Puigvert, M et al. (2014) The plant metacaspase AtMC1 in pathogen-triggered programmed cell death and aging: functional linkage with autophagy. Cell Death Differ 21:1399-408 |
| Bonardi, Vera; Cherkis, Karen; Nishimura, Marc T et al. (2012) A new eye on NLR proteins: focused on clarity or diffused by complexity? Curr Opin Immunol 24:41-50 |
| Argueso, Cristiana T; Ferreira, Fernando J; Epple, Petra et al. (2012) Two-component elements mediate interactions between cytokinin and salicylic acid in plant immunity. PLoS Genet 8:e1002448 |
| Coll, N S; Epple, P; Dangl, J L (2011) Programmed cell death in the plant immune system. Cell Death Differ 18:1247-56 |
| Bonardi, Vera; Tang, Saijun; Stallmann, Anna et al. (2011) Expanded functions for a family of plant intracellular immune receptors beyond specific recognition of pathogen effectors. Proc Natl Acad Sci U S A 108:16463-8 |
| Jaillais, Yvon; Belkhadir, Youssef; Balsemao-Pires, Emilia et al. (2011) Extracellular leucine-rich repeats as a platform for receptor/coreceptor complex formation. Proc Natl Acad Sci U S A 108:8503-7 |
| Coll, Nuria S; Vercammen, Dominique; Smidler, Andrea et al. (2010) Arabidopsis type I metacaspases control cell death. Science 330:1393-7 |
| Eitas, Timothy K; Dangl, Jeffery L (2010) NB-LRR proteins: pairs, pieces, perception, partners, and pathways. Curr Opin Plant Biol 13:472-7 |
| Nishimura, Marc T; Dangl, Jeffery L (2010) Arabidopsis and the plant immune system. Plant J 61:1053-66 |
| Todesco, Marco; Balasubramanian, Sureshkumar; Hu, Tina T et al. (2010) Natural allelic variation underlying a major fitness trade-off in Arabidopsis thaliana. Nature 465:632-6 |
Showing the most recent 10 out of 22 publications
