title: Arabidopsis ABI5 plays a role in regulating ROS homeostasis by activating CATALASE 1 transcription in seed germination.
abstract: It has been known that ABA INSENSITIVE 5 (ABI5) plays a vital role in regulating seed germination. In the present study, we showed that inhibition of the catalase activity with 3-amino-1,2,4-triazole (3-AT) inhibits seed germination of Col-0, abi5 mutants and ABI5-overexpression transgenic lines. Compared with Col-0, the seeds of abi5 mutants showed more sensitive to 3-AT during seed germination, while the seeds of ABI5-overexpression transgenic lines showed more insensitive. H2O2showed the same effect on seed germination of Col-0, abi5 mutants and ABI5-overexpression transgenic lines as 3-AT. These results suggest that ROS is involved in the seed germination mediated by ABI5. Further, we observed that T-DNA insertion mutants of the three catalase members in Arabidopsis displayed 3-AT-insensitive or -hypersensitive phenotypes during seed germination, suggesting that these catalase members regulate ROS homeostasis in a highly complex way. ABI5 affects reactive oxygen species (ROS) homeostasis by affecting CATALASE expression and catalase activity. Furthermore, we showed that ABI5 directly binds to the CAT1 promoter and activates CAT1 expression. Genetic evidence supports the idea that CAT1 functions downstream of ABI5 in ROS signaling during seed germination. RNA-sequencing analysis indicates that the transcription of the genes involved in ROS metabolic process or genes responsive to ROS stress is impaired in abi5-1 seeds. Additionally, expression changes in some genes correlative to seed germination were showed due to the change in ABI5 expression under 3-AT treatment. Together, all the findings suggest that ABI5 regulates seed germination at least partly by affecting ROS homeostasis.
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Bi
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Yong-Tao
authors.initials: YT
authors.lastname: Yu
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Liang
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Lu
authors.affiliation: Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China. wangxf@biomed.tsinghua.edu.cn.
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Wang
mesh_terms: D000640:Amitrole / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005838:Genotype; D018525:Germination / Q000502:physiology; D006706:Homeostasis; D006861:Hydrogen Peroxide / Q000378:metabolism; D009154:Mutation; D030821:Plants, Genetically Modified; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015398:Signal Transduction; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: C409743:ABI5 protein, Arabidopsis; D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; C000621577:CAT1 protein, Arabidopsis; D002374:Catalase; D000640:Amitrole
keywords: ABI5; Arabidopsis thaliana; Catalase; ROS homeostasis; Seed germination