title: FtsHi4 is essential for embryogenesis due to its influence on chloroplast development in Arabidopsis.
abstract: Chloroplast formation is associated with embryo development and seedling growth. However, the relationship between chloroplast differentiation and embryo development remains unclear. Five FtsHi genes that encode proteins with high similarity to FtsH proteins, but lack Zn2+-binding motifs, are present in the Arabidopsis genome. In this study, we showed that T-DNA insertion mutations in the Arabidopsis FtsHi4 gene resulted in embryo arrest at the globular-to-heart-shaped transition stage. Transmission electron microscopic analyses revealed abnormal plastid differentiation with a severe defect in thylakoid formation in the mutant embryos. Immunocytological studies demonstrated that FtsHi4 localized in chloroplasts as a thylakoid membrane-associated protein, supporting its essential role in thylakoid membrane formation. We further showed that FtsHi4 forms protein complexes, and that there was a significant reduction in the accumulation of D2 and PsbO (two photosystem II proteins) in mutant ovules. The role of FtsHi4 in chloroplast development was confirmed using an RNA-interfering approach. Additionally, mutations in other FtsHi genes including FtsHi1, FtsHi2, and FtsHi5 caused phenotypic abnormalities similar to ftshi4 with respect to plastid differentiation during embryogenesis. Taken together, our data suggest that FtsHi4, together with FtsHi1, FtsHi2, and FtsHi5 are essential for chloroplast development in Arabidopsis.
authors: Department of Life Sciences, Qilu Normal University, Jinan, China.
authors: Xiaoduo
authors: X
authors: Lu
authors: Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.
authors: Dongyuan
authors: D
authors: Zhang
authors: Department of Life Sciences, Qilu Normal University, Jinan, China.
authors: Shipeng
authors: S
authors: Li
authors: School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China.
authors: Yanping
authors: Y
authors: Su
authors: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China; National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, China.
authors: Qiuju
authors: Q
authors: Liang
authors: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
authors: Hongyan
authors: H
authors: Meng
authors: School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China.
authors: Songdong
authors: S
authors: Shen
authors: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China; National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, China.
authors: Yunliu
authors: Y
authors: Fan
authors: Institute of Botany, Chinese Academy of Sciences, Beijing, China.
authors: Chunming
authors: C
authors: Liu
authors: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China; National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, China.
authors: Chunyi
authors: C
authors: Zhang
mesh_terms: D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D002736:Chloroplasts / Q000378:metabolism / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D055785:Gene Knockdown Techniques; D016297:Mutagenesis, Site-Directed; D034622:RNA Interference; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D060431:Thylakoid Membrane Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D020524:Thylakoids / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C000603583:FtsHi4 protein, Arabidopsis; D060431:Thylakoid Membrane Proteins