Extremophile plants: molecular mechanisms of stress tolerance and their practical applications
Abiotic stresses, such as drought, salinity, extreme temperatures, chemical toxicity, and prooxidants are serious threats to agriculture and natural ecosystems. Abiotic stress is the primary cause of losses in the majority of wild species and crop worldwide, reducing average yields for most major crop plants by more than 50%. Despite this, unique extremophile plants exist, which can successfully grow in harsh environments. An extremophile (from Latin extremus meaning “extreme” and Greek philiā meaning “love”) is an organism that thrives in extreme conditions that would kill other, less specialized organisms. Among the extremophiles are bryophytes, lichens – symbiotic photosynthesizing organisms, and also some higher vascular plants. Bryophytes and lichens form the dominant plant life over large areas of the world, for example as components of dryland crusts in the steppe, the Arctic, sub-Arctic and Antarctic. To survive in harsh environments, bryophytes and lichens developed tolerance mechanisms to desiccation, high temperature, and low demand for nutrients. We are only beginning to understand their survival mechanisms. One of the factors that determine their high stress tolerance is the presence of redox enzymes with unusual physico-chemical properties. Extremophile plants represent repositories of genes, which with the help of modern technologies can be used to design “super-enzymes” and synthesize “super-metabolites”. The great challenge of modern biotechnology is to develop novel approaches to improving the stress tolerance of non-extremophile plants such as crops using the knowledge of the survival mechanisms of extremophile plants. Furthermore, “extreme” redox enzymes can be an effective instrument in phytoremediation by detoxifying xenobiotics and synthetic dyes and also in industrial processes that require enzymes that can “work” in harsh conditions. The use of enzymes and metabolites derived from extremophile plants represents an ecologically friendly alternative to highly toxic compounds, which are employed for the same purpose at present. This talk will review how creating a novel platform based on extremophile plants can lead to new biotechnological approaches for solving problems in agriculture, food production and numerous industrial processes.