Molecular Strategies of Desiccation Tolerance in Resurrection Plants
Introduction
Resurrection plants are a group of plant species that can survive extreme dehydration, often for prolonged periods, and then recover upon rehydration. This remarkable ability is due to a suite of molecular strategies that these plants employ to tolerate desiccation. These strategies involve changes at the genetic, protein, and metabolic levels, and they are the focus of this article.
Genetic Strategies
Resurrection plants have evolved a unique set of genes that are specifically activated during desiccation. These desiccation-related proteins (DRPs) are thought to play a crucial role in protecting the plant's cellular machinery from the damaging effects of water loss. Some of these genes encode for proteins that help to stabilize cell membranes and proteins, while others are involved in the synthesis of protective molecules such as trehalose and late embryogenesis abundant (LEA) proteins.
Protein Strategies
Proteins play a vital role in the desiccation tolerance of resurrection plants. One of the key protein strategies is the synthesis of LEA proteins. These proteins are highly hydrophilic and are thought to replace water in the cell during desiccation, thereby maintaining the structure and function of cellular proteins. Other proteins, such as heat shock proteins (HSPs) and dehydrins, are also synthesized in response to desiccation and are thought to help protect the cell from damage.
Metabolic Strategies
Resurrection plants also employ a range of metabolic strategies to survive desiccation. One of the key metabolic responses is the accumulation of compatible solutes, such as trehalose and sucrose. These molecules help to stabilize cell structures and proteins during desiccation. In addition, resurrection plants also increase the production of reactive oxygen species (ROS) scavengers, such as antioxidants and enzymes, to protect the cell from oxidative damage.
Conclusion
The molecular strategies of desiccation tolerance in resurrection plants are complex and multifaceted, involving changes at the genetic, protein, and metabolic levels. These strategies not only allow these plants to survive in extreme environments, but they also provide valuable insights into how plants in general respond to stress.