Heat acclimation and cross-tolerance against anoxia in Arabidopsis. Plant Cell Environ

Department of Crop Plant Biology, University of Pisa, Via Mariscoglio 34, 56124 Pisa, Italy.
Plant Cell and Environment (Impact Factor: 6.96). 08/2008; 31(7):1029-37. DOI: 10.1111/j.1365-3040.2008.01816.x
Source: PubMed


Arabidopsis seedlings are highly sensitive to low oxygen and they die rapidly when exposed to anoxia. Tolerance to anoxia depends on the ability to efficiently use carbohydrates through the fermentative pathway, as highlighted by the lower tolerance displayed by a mutant devoid of alcohol dehydrogenase. Other mechanisms of tolerance are also possible and may include a role for heat-induced genes. In fact, heat shock proteins (HSPs) are induced by anoxia. This suggests that there may be a cross-adaptation mechanism between heat and anoxic stress, and in this work, we studied the acclimation of Arabidopsis seedlings both to low oxygen and heat. The results show that seedlings subjected to hypoxia or heat pretreatment survive anoxia much better. Interestingly, we also observed an increased anoxia tolerance in heat-treated alcohol dehydrogenase (adh) mutant plants. On the other hand, anoxic pretreatment does not confer tolerance to heat stress. The success of the induction of HSPs by anoxia is in direct relation to the amount of sucrose available, and this in turn relates to how well seedlings will survive under anoxia. HSP transcripts were also detected during seed development and germination, two hypoxia-prone processes, suggesting that hypoxia-induced HSP expression is physiologically relevant.

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    • "In pharmacology and physiology research outside toxicology, many empirical examples of crossadaptation , cross-resistance and cross-sensitization are documented (Antelman et al., 1992; Antelman et al., 2000; Hale, 1969; Milisav et al., 2012). For instance, hypoxia cross-adapts with cold or hot temperatures (Banti et al., 2008; Launay et al., 2006; Lunt et al., 2010; Ning and Chen, 2006); stress cross-sensitizes with amphetamine (Antelman et al., 1980); sucrose cross-sensitizes with amphetamine or cocaine (Avena and Hoebel, 2003; Gosnell, 2005); formaldehyde cross-sensitizes with cocaine (Sorg et al., 2001; Sorg et al., 1998); heat shock, sodium arsenite, and cadmium chloride can cross-sensitize with one another depending on their heat shock protein activation patterns (Wiegant et al., 1998). The inference from such evidence is that an external agent at various doses is a salient biological stressor for the cell or organism as a complex adaptive system in addition to the local, receptor-specific actions (Bell and Schwartz, 2013). "
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