Plants are sessile organisms and are therefore unable to escape stressful conditions. Instead, they rely on various behavioural, physiological and molecular mechanisms to limit the impact of both biotic or abiotic stresses. Water deprivation is a very common event for land plants and is among the leading causes of crop yield reduction worldwide. In the coming years the negative effect of drought on global agriculture is likely to worsen due to rising average temperatures and the increased need for food caused by the population growth (Lyall, Gechev, 2020). Moreover, it is important to note that most relevant crops are not tolerant to drought.Plants can cope with drought using various mechanisms, including avoidance (ephemeral plants), maintaining high water potential (succulent plants), and drought tolerance (ability to maintain physiological activities at low water potential). An unusual group of angiosperms, commonly designated as resurrection plants, includes diverse monocot and dicot families that exhibit vegetative desiccation tolerance (VDT): they can dry down entirely during extreme drought and quickly resume growth and regain normal appearance after rehydration (Dinakar and Bartels, 2013; Gechev et al., 2013). A current hypothesis for the evolution of VDT is that it is based on the reprogramming of the existing desiccation tolerance (DT) mechanisms in seeds.
Figure: Haberlea rhodopensis plants cultivated in vitro. A – fully hydrated; B – desiccated; C – 2 days after rehydration.
Evidence from transcriptomic, metabolomic and genomic data supports this hypothesis, and many of the core protective strategies used by resurrection plants are similar to the ones found in maturing seeds. This would imply that the genetic potential for VDT is widespread even among sensitive species and could be exploited to improve economically important crops. Another intriguing observation is that some resurrection plants are able to tolerate other stresses, including low temperature/freezing, severe oxidative stress, and long-term darkness (Benina et al., 2013; Durgud et al., 2019). Therefore, research on resurrection plants has not only significant fundamental scientific importance but also immediate practical application - especially in the context of the constantly changing climatic conditions, growing population and the ever-increasing demand for higher quality and sustainably produced foods. The interest in these unique plants is additionally fueled by the identification of secondary metabolites from resurrection species with medicinal (anticancer and antiviral) activities (Gechev et al., 2014).
- Lyall R., Gechev T. (2020) Multi-omics insights into the evolution of angiosperm resurrection plants. Annual Plant Reviews Online. 3(1): 77–110.
- Dinakar C., Bartels D. (2013) Desiccation tolerance in resurrection plants: new insights from transcriptome, proteome and metabolome analysis. Frontiers in Plant Science. 4: 482.
- Gechev T., Benina M., Obata T., … Toneva V. (2013) Molecular mechanisms of desiccation tolerance in the resurrection glacial relic Haberlea rhodopensis. Cellular and Molecular Life Sciences. 70: 689–709.
- Benina M., Obata T., Mehterov N., … Gechev T. (2013) Comparative metabolic profiling of Haberlea rhodopensis, Thellungiella halophyla, and Arabidopsis thaliana exposed to low temperature. Frontiers in Plant Science. 4: 499.
- Durgud M., Gupta S., Ivanov I, … Gechev T. (2018) Molecular mechanisms preventing senescence in response to prolonged darkness in a desiccation–tolerant plant. Plant Physiology. 177(3): 1319–1338.
- Gechev T., Hille J., Woerdenbag H., … Mueller-Roeber B. (2014) Natural products from resurrection plants: potential for medical applications. Biotechnology Advances. 32(6): 1091–1101.