Location: Plant Genetics Research
2012 Annual Report
This project is associated with Objective 2: Develop strategies and mechanisms for improving drought-stress tolerance of maize, and is a collaborative effort between ARS and Colgate University and funded through the Harvey Picker Institute for Disciplinary Studies in the Sciences and Mathematics. The primary objective of the project, for ARS, is to uncover the mechanisms by which different life stages of ferns survive desiccation. The ARS approach is to look at key genetic components of desiccation tolerance and to determine their regulation during dehydration under controlled drying conditions. Initial studies focused on isolating and characterizing dehydrin protein expression, both at the transcriptional and translational levels, in a number of fern subjected to dehydration. After much work we focused our attention to the fern, Lomariopsis vestita, as it exhibits a unique expression of desiccation tolerance, going from tolerant to sensitive, as it transitions from an epiphytic to a terrestrial growth pattern. We previously explored the use of dehydrins as a marker of tolerance in these ferns and it has proven to be unsatisfactory on many levels. We moved to a different marker, the Early Light Inducible Protein (ELIP) gene family, and have cloned a gene that produces a dehydration inducible transcript. We completed a preliminary transcriptome analysis of the leaves of this fern. We initiated an assay of the expression of this gene, along with others involved in photosynthesis through drying rehydration cycles in Lomariopsis vestita. The progress made was exactly as outlined in the project for the ARS portion and made significant inroads into understanding how desiccation tolerance is regulated in plants. These studies will ultimately identify the regulation and genetic components of the complex phenotype of drought tolerance and its improvement in crops.