Gesneriads, a Source of Resurrection and Double-Tolerant Species: Proposal of New Desiccation- and Freezing-Tolerant Plants and Their Physiological Adaptations

In the current scenario of climate change, plants need to overcome a great amplitude of temperatures and increasingly common droughts in the very same space. Gesneriads are a worldwide family of plants in which many “resurrection” species have arisen: plants with the ability to withstand long periods of time with very little water content and successfully revive upon water availability. Due to their rocky and mountainous habitat, many of them have to face a great temperature variability and freezing temperatures, and indeed, their resurrection ability and freezing tolerance share similar metabolic responses. Tolerance of gesneriads to different environmental stresses is thought to be applicable in crop growth improvement, but their difficult indoor cultivation and outdoor accessibility are major obstacles for their study. Therefore, this review aims to identify common patterns in the already known resurrection species to propose new tentative resurrection gesneriads, as well as gather the metabolic responses to desiccation and freezing stress as a way of making them more reachable to the scientific community.