title: Epigenetic Changes are Associated with Programmed Cell Death Induced by Heat Stress in Seedling Leaves of Zea mays.
abstract: Histone modification plays a crucial role in regulation of chromatin architecture and function, responding to adverse external stimuli. However, little is known about a possible relationship between epigenetic modification and programmed cell death (PCD) in response to environmental stress. Here, we found that heat stress induced PCD in maize seedling leaves which was characterized by chromatin DNA laddering and DNA strand breaks detected by a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) test. The activities of the reactive oxygen species (ROS)-related enzymes superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were progressively increased over time in the heat-treated seedlings. However, the concentration of H2O2 remained at relatively lower levels, while the concentration of superoxide anion ([Formula: see text]) was increased, accompanied by the occurrence of higher ion leakage rates after heat treatment. The total acetylation levels of histones H3K9, H4K5 and H3 were significantly increased, whereas the di-methylation level of histone H3K4 was unchanged and the di-methylation level of histone H3K9 was decreased in the seedling leaves exposed to heat stress compared with the control seedlings, accompanied by increased nucleolus size indicative of chromatin decondensation. Furthermore, treatment of seedlings with trichostatin A (TSA), which always results in genomic histone hyperacetylation, caused an increase in the [Formula: see text] level within the cells. The results suggested that heat stress persistently induced [Formula: see text], leading to PCD in association with histone modification changes in the maize leaves.
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Pu
authors: P
authors: Wang
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Lin
authors: L
authors: Zhao
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Haoli
authors: H
authors: Hou
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Hao
authors: H
authors: Zhang
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Yan
authors: Y
authors: Huang
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Yapei
authors: Y
authors: Wang
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Hui
authors: H
authors: Li
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Fei
authors: F
authors: Gao
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors: Shihan
authors: S
authors: Yan
authors: State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China ljli@whu.edu.cn.
authors: Lijia
authors: L
authors: Li
mesh_terms: D000107:Acetylation / Q000187:drug effects; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D015153:Blotting, Western; D002843:Chromatin / Q000378:metabolism; D004249:DNA Damage; D044127:Epigenesis, Genetic / Q000187:drug effects; D005091:Exons / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018869:Heat-Shock Response / Q000235:genetics*; D006657:Histones / Q000378:metabolism; D006877:Hydroxamic Acids / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D007477:Ions; D008745:Methylation / Q000187:drug effects; D008954:Models, Biological; D018515:Plant Leaves / Q000166:cytology* / Q000187:drug effects / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D036226:Seedlings / Q000166:cytology / Q000187:drug effects / Q000235:genetics*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*; D003313:Zea mays / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000502:physiology
chemical_list: D002843:Chromatin; D006657:Histones; D006877:Hydroxamic Acids; D007477:Ions; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C012589:trichostatin A
keywords: Heat stress; Histone modification; Maize seedlings; PCD; Superoxide anion