Overexpression of Multiple Dehydrin Genes Enhances Tolerance to Freezing Stress in Arabidopsis

Abstract

To elucidate the contribution of dehydrins (DHNs) to freezing stress tolerance in Arabidopsis, transgenic plants overexpressing multiple DHN genes were generated. Chimeric double constructs for expression of RAB18 and COR47 (pTP9) or LTI29 and LTI30 (pTP10) were made by fusing the coding sequences of the respective DHN genes to the cauliflower mosaic virus 35S promoter. Overexpression of the chimeric genes in Arabidopsis resulted in accumulation of the corresponding dehydrins to levels similar or higher than in cold-acclimated wild-type plants. Transgenic plants exhibited lower LT 50 values and improved survival when exposed to freezing stress compared to the control plants. Post-embedding immuno electron microscopy of high-pressure frozen, freeze-substituted samples revealed partial intracellular translocation from cytosol to the vicinity of the membranes of the acidic dehydrin LTI29 during cold acclimation in transgenic plants. This study provides evidence that dehydrins contribute to freezing stress tolerance in plants and suggests that this could be partly due to their protective effect on membranes.

Genetic approaches towards overcoming water deficit in plants - special emphasis on LEAs

“…Overproduction of citrus dehydrin (CoCOR19) in tobacco resulted in slight decrease in ion leakage under chilling and freezing stress. Moreover, recent strategies such as overexpression of multiple DHNs [Chimeric double constructs RAB18 and COR47(pTP9) or LTI29 and LTI30(pTP10)] genes in Arabidopsis resulted in improved survival especially when exposed to freezing stress (Puhakainen et al, 2004). The intracellular translocation of the acidic dehydrin LTI29 from the cytosol to vicinity of the membranes during cold acclimation in transgenic plants suggests its plausible membrane protection mechanism.…”

Tunable Membrane Binding of the Intrinsically Disordered Dehydrin Lti30, a Cold-Induced Plant Stress Protein

“…However, experimental tests of this idea have generated conflicting results. Favoring membrane binding, some dehydrins are found to colocalize with membrane surfaces in stressed plant cells (Danyluk et al, 1998;Puhakainen et al, 2004). Moreover, the maize (Zea mays) dehydrin DHN1 (YSK 2 ; see Figure 1 for nomenclature) and the two Arabidopsis thaliana dehydrins, Lti29 and Erd14, are also found to interact with liposomes in vitro (Koag et al, 2003;Kovacs et al, 2008;Koag et al, 2009).…”

Changes of some anti-oxidative physiological indices under soil water deficits among 10 wheat (Triticum aestivum L.) genotypes at tillering stage

“…Drought is a complex physical-chemical process, in which many biological macromolecules and small molecules are involved, such as nucleic acids (DNA, RNA, microRNA), proteins, carbohydrates, lipids, hormones, ions, free radicals, mineral elements [3,8,12,13,18,20,22,26,31,43,49,50,55,65]. In addition, drought is also related to salt stress, cold stress, high temperature stress, acid stress, alkaline stress, pathological reactions, senescence, growth, development, cell cycle, UV-B damage, wounding, embryogenesis, flowering, signal transduction and so on [16,17,[26][27][28]36,37,[44][45][46][47][52][53][54]62]. Therefore, drought is connected with almost all aspects of biology.…”

“…Just 2 years ago, European Commission, who once kept conservative to biotechnological breeding, constructed a big project: Plants for the Future in which much is involved in resistance drought [5]. Many advances in relation to this hot topic, including molecular mechanism of antidrought and corresponding molecular breeding have taken place [4,10,16,17,21,[23][24][25]30,31,35,37,39,42,48,[55][56][57][58][59]. Although the obtained transgenic crops (mainly, wheat) by different types of gene technology all exhibit resistance drought to some extent, they have many shortfalls related to agronomical performance and/or development [1,16,17,21,24,30,39,49,56].…”