title: The Arabidopsis NAC transcription factor NTL4 participates in a positive feedback loop that induces programmed cell death under heat stress conditions.
abstract: Programmed cell death (PCD) is an integral component of plant development and adaptation under adverse environmental conditions. Reactive oxygen species (ROS) are one of the most important players that trigger PCD in plants, and ROS-generating machinery is activated in plant cells undergoing PCD. The membrane-bound NAC transcription factor NTL4 has recently been proven to facilitate ROS production in response to drought stress in Arabidopsis. In this work, we show that NTL4 participates in a positive feedback loop that bursts ROS accumulation to modulate PCD under heat stress conditions. Heat stress induces NTL4 gene transcription and NTL4 protein processing. The level of hydrogen peroxide (H2O2) was elevated in 35S:4ΔC transgenic plants that overexpress a transcriptionally active nuclear NTL4 form but significantly reduced in NTL4-deficient ntl4 mutants under heat stress conditions. In addition, heat stress-induced cell death was accelerated in the 35S:4ΔC transgenic plants but decreased in the ntl4 mutants. Notably, H2O2 triggers NTL4 gene transcription and NTL4 protein processing under heat stress conditions. On the basis of these findings, we conclude that NTL4 modulates PCD through a ROS-mediated positive feedback control under heat stress conditions, possibly providing an adaptation strategy by which plants ensure their survival under extreme heat stress conditions.
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Sangmin
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Hyo-Jun
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Sung Un
authors.initials: SU
authors.lastname: Huh
authors.affiliation: College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Paek
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Jun-Ho
authors.initials: JH
authors.lastname: Ha
authors.affiliation: Department of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-742, Republic of Korea. Electronic address: cmpark@snu.ac.kr.
authors.forename: Chung-Mo
authors.initials: CM
authors.lastname: Park
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D017209:Apoptosis / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D016923:Cell Death; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism; D030821:Plants, Genetically Modified; D013312:Stress, Physiological / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D014157:Transcription Factors; D006861:Hydrogen Peroxide
keywords: Abscisic acid (ABA); Arabidopsis; H(2)O(2); Heat stress; Membrane-bound transcription factor (MTF); Programmed cell death (PCD)