Identification of salt gland-associated genes and characterization of a dehydrin from the salt secretor mangrove Avicennia officinalis

BMC Plant Biology

Research Article

Tit-Meng Lim¹  Qingsong Lin¹  Pavithra A Jyothi-Prakash²  Chiang-Shiong Loh²  Prakash P Kumar³  Bijayalaxmi Mohanty⁴  Edward Wijaya⁵ 

[1] Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, Republic of Singapore;Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, Republic of Singapore;NUS Environmental Research Institute (NERI), National University of Singapore, #02-01, T-Lab Building, 5A Engineering Drive 1, Singapore, Republic of Singapore;Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, Republic of Singapore;Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore, Republic of Singapore;Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, Republic of Singapore;IFReC, Osaka University, 3-1 Yamada-oka, 565-0871, Suita, Osaka, Japan;

关键词: Avicennia officinalis;    Salinity;    Dehydrin;    Subtractive hybridization;    Leaf salt glands;    Drought stress;   

DOI  :  10.1186/s12870-014-0291-6

 received in 2014-08-04, accepted in 2014-10-15,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundSalt stress is a major challenge for growth and development of plants. The mangrove tree Avicennia officinalis has evolved salt tolerance mechanisms such as salt secretion through specialized glands on its leaves. Although a number of structural studies on salt glands have been done, the molecular mechanism of salt secretion is not clearly understood. Also, studies to identify salt gland-specific genes in mangroves have been scarce.ResultsBy subtractive hybridization (SH) of cDNA from salt gland-rich cell layers (tester) with mesophyll tissues as the driver, several Expressed Sequence Tags (ESTs) were identified. The major classes of ESTs identified include those known to be involved in regulating metabolic processes (37%), stress response (17%), transcription (17%), signal transduction (17%) and transport functions (12%). A visual interactive map generated based on predicted functional gene interactions of the identified ESTs suggested altered activities of hydrolase, transmembrane transport and kinases. Quantitative Real-Time PCR (qRT-PCR) was carried out to validate the expression specificity of the ESTs identified by SH. A Dehydrin gene was chosen for further experimental analysis, because it is significantly highly expressed in salt gland cells, and dehydrins are known to be involved in stress remediation in other plants. Full-length Avicennia officinalis Dehydrin1 (AoDHN1) cDNA was obtained by Rapid Amplification of cDNA Ends. Phylogenetic analysis and further characterization of this gene suggested that AoDHN1 belongs to group II Late Embryogenesis Abundant proteins. qRT-PCR analysis of Avicennia showed up-regulation of AoDHN1 in response to salt and drought treatments. Furthermore, some functional insights were obtained by growing E. coli cells expressing AoDHN1. Growth of E. coli cells expressing AoDHN1 was significantly higher than that of the control cells without AoDHN1 under salinity and drought stresses, suggesting that the mangrove dehydrin protein helps to mitigate the abiotic stresses.ConclusionsThirty-four ESTs were identified to be enriched in salt gland-rich tissues of A. officinalis leaves. qRT-PCR analysis showed that 10 of these were specifically enriched in the salt gland-rich tissues. Our data suggest that one of the selected genes, namely, AoDHN1 plays an important role to mitigate salt and drought stress responses.

【 授权许可】

Unknown   
© Jyothi-Prakash et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.