FtsHi4 is essential for embryogenesis due to its influence on chloroplast development in Arabidopsis
Authors: Dongyuan Zhang
Yanping Su
Xiaoduo Lu
Hongyan Meng
Yunliu Fan
Qiuju Liang
Songdong Shen
Chunming Liu
Chunyi Zhang
Shipeng Li
Journal: PLoS ONE (2014)
Discipline: Multidisciplinary
Keywords: Chloroplast formation; embryo development; seedling growth; FtsHi genes; Arabidopsis genome
Affiliations: Department of Life Sciences, Qilu Normal University, Jinan, China., Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China., School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China., Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China; National Key Facility for Crop Gene Resources and Genetic Improvement (NFCRI), Beijing, China., Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China., Institute of Botany, Chinese Academy of Sciences, Beijing, China.

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. 

Retracted: No

PubPeer comments:
 February 2020 Correction, found here: https: journals.plos.org plosone article?id=10.1371 journal.pone.0229232 It reads:  In Fig 7B of this article [1], the PsbO data were duplicated in error as representing the Cyt f results. In the updated figure provided here, the Cyt f panel has been replaced with the correct image from the original experiment. The original uncropped blot images supporting Fig 7B are provided in Supporting Information S1u2013S6 Files of this notice. A member of PLOS ONEu2019s Editorial Board confirmed that the updated figure supports the results as reported in the original article. Here is the original Figure 7B, marked with red boxes, as reported to the journal in July 2014. ![file] I thank the authors and journal staff for correcting this error. ,