AUTHOR=Benina Maria , Obata Toshihiro , Mehterov Nikolay , Ivanov Ivan , Petrov Veselin , Toneva Valentina , Fernie Alisdair , Gechev Tsanko S.

TITLE=Comparative metabolic profiling of Haberlea rhodopensis, Thellungiella halophyla, and Arabidopsis thaliana exposed to low temperature

JOURNAL=Frontiers in Plant Science

VOLUME=4

YEAR=2013

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2013.00499

DOI=10.3389/fpls.2013.00499

ISSN=1664-462X

ABSTRACT=<p><italic>Haberlea rhodopensis</italic> is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea's remarkable stress tolerance, the metabolic reconfiguration of <italic>H. rhodopensis</italic> during low temperature (4°C) and subsequent return to optimal temperatures (21°C) was investigated and compared with that of the stress tolerant <italic>Thellungiella halophyla</italic> and the stress sensitive <italic>Arabidopsis thaliana</italic>. Metabolic analysis by GC-MS revealed intrinsic differences in the metabolite levels of the three species even at 21°C. <italic>H. rhodopensis</italic> had significantly more raffinose, melibiose, trehalose, rhamnose, <italic>myo</italic>-inositol, sorbitol, galactinol, erythronate, threonate, 2-oxoglutarate, citrate, and glycerol than the other two species. <italic>A. thaliana</italic> had the highest levels of putrescine and fumarate, while <italic>T. halophila</italic> had much higher levels of several amino acids, including alanine, asparagine, beta-alanine, histidine, isoleucine, phenylalanine, serine, threonine, and valine. In addition, the three species responded differently to the low temperature treatment and the subsequent recovery, especially with regard to the sugar metabolism. Chilling induced accumulation of maltose in <italic>H. rhodopensis</italic> and raffinose in <italic>A. thaliana</italic> but the raffinose levels in low temperature exposed Arabidopsis were still much lower than these in unstressed Haberlea. While all species accumulated sucrose during chilling, that accumulation was transient in <italic>H. rhodopensis</italic> and <italic>A. thaliana</italic> but sustained in <italic>T. halophila</italic> after the return to optimal temperature. Thus, Haberlea's metabolome appeared primed for chilling stress but the low temperature acclimation induced additional stress-protective mechanisms. A diverse array of sugars, organic acids, and polyols constitute Haberlea's main metabolic defence mechanisms against chilling, while accumulation of amino acids and amino acid derivatives contribute to the low temperature acclimation in Arabidopsis and Thellungiella. Collectively, these results show inherent differences in the metabolomes under the ambient temperature and the strategies to respond to low temperature in the three species.</p>