@article{fa63ff1cd2f64d8b9188906793b0ddd4,
title = "Dehydration-induced DnaK2 chaperone is involved in PSII repair of a desiccation-tolerant Cyanobacterium",
abstract = "Maintaining the structural integrity of the photosynthetic apparatus during dehydration is critical for effective recovery of photosynthetic activity upon rehydration in a variety of desiccation-tolerant plants, but the underlying molecular mechanism is largely unclear. The subaerial cyanobacterium Nostoc flagelliforme can survive extreme dehydration conditions and quickly recovers its photosynthetic activity upon rehydration. In this study, we found that the expression of the molecular chaperone NfDnaK2 was substantially induced by dehydration, and NfDnaK2 proteins were primarily localized in the thylakoid membrane. NfDnaJ9 was identified to be the cochaperone partner of NfDnaK2, and their encoding genes shared similar transcriptional responses to dehydration. NfDnaJ9 interacted with the NfFtsH2 protease involved in the degradation of damaged D1 protein. Heterologous expression of NfdnaK2 enhanced PSII repair and drought tolerance in transgenic Nostoc sp. PCC 7120. Furthermore, the nitrate reduction (NarL)/nitrogen fixation (FixJ) family transcription factors response regulator (NfRre1) and photosynthetic electron transport-dependent regulator (NfPedR) were identified as putative positive regulators capable of binding to the promoter region of NfdnaK2 and they may mediate dehydration-induced expression of NfdnaK2 in N. flagelliforme. Our findings provide novel insights into the molecular mechanism of desiccation tolerance in some xerotolerant microorganisms, which could facilitate future synthetic approaches to the creation of extremophiles in microorganisms and plants.",
author = "Huazhong Shi and Xu, {Hai Feng} and Dai, {Guo Zheng} and Ye, {De Min} and Shang, {Jin Long} and Song, {Wei Yu} and Qiu, {Bao Sheng}",
note = "Funding Information: 1This work was supported by the National Natural Science Foundation of China (grant nos. 31670332 and 31600190), Fundamental Research Funds for the Central Universities (CCNU18ZDPY05 and CCNU19QD013), and the Hubei Provincial Natural Science Foundation (grant no. 2013CFB211). 2These authors contributed equally to the article. 3Author for contact: bsqiu@mail.ccnu.edu.cn. 4Senior author. The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Bao-Sheng Qiu (bsqiu@mail.ccnu.edu.cn). B.-S.Q. and G.-Z.D. conceived and supervised the study; H.-F.X., G.-Z.D., D.-M.Y., and W.-Y.S. conducted the major analyses in this work; J.-L.S. was engaged in the bioinformatics analysis; H.-F.X., G.-Z.D., H.S., and B.-S.Q. analyzed the data and wrote the article. www.plantphysiol.org/cgi/doi/10.1104/pp.19.01149 Funding Information: 1This work was supported by the National Natural Science Foundation of China (grant nos. 31670332 and 31600190), Fundamental Research Funds for the Central Universities (CCNU18ZDPY05 and CCNU19QD013), and the Hubei Provincial Natural Science Foundation (grant no. 2013CFB211). We thank Dr. Hai-Bo Jiang, Dr. Xiang Gao, Dr. Zhong-Chun Zhang and Dr. Yi-Wen Yang (Central China Normal University) for their valuable advice, and Da Huang, Jian Wan, and Chen Xu (Central China Normal University) for assisting in the liquid chromatography tandem MS data collection and analysis. We also thank Xu-Dong Xu (Institute of Hydrobiology, Chinese Academy of Sciences) for kindly providing the pHB1347 plasmid and E. coli HB101. Publisher Copyright: {\textcopyright} 2020 American Society of Plant Biologists. All Rights Reserved.",
year = "2020",
month = feb,
day = "5",
doi = "10.1104/pp.19.01149",
language = "English",
volume = "182",
pages = "1991--2005",
journal = "Plant Physiology",
number = "4",
}