Understanding the mechanisms used by plants to survive stressful environmental
conditions, such as water deficits due to drought is vital to the development of genetic
engineering strategies to improve or retain agricultural productivity in the face of
increasing environmental insults, changes in rainfall patterns and global warming.
Desiccation tolerance is a rare adaptive response of resurrection plants to exist in
environments with intermittent drought by entering into a state of metabolic inactivity,
wherein vegetative structures are preserved under air-dried conditions. Upon rewatering,
these plants resume their metabolic activities and repair any damage that occurred while
in the dry state. The mechanistic basis of desiccation tolerance can be better understood
by studying it using integrative functional genomics approaches including
transcriptomics, proteomics, and metabolomics. In this study, protein expression patterns
within fully hydrated and desiccated tissues of Selaginella lepidophylla were investigated
using a gel-based proteomics approach. A phenol-based protein extraction protocol was
optimized for S. lepidophylla tissues by including a series of washing steps with
methanol, acetone and ether in order to remove membrane lipids and polyphenolics.
Protein expression profiles were then compared using two-dimensional difference
polyacrylamide gel electrophoresis (2D-DIGE). The 2D-DIGE analysis revealed that 130
proteins that were differentially expressed with 107 proteins showing increased
abundance and 23 showing decreased abundance in the dry state compared with the
hydrated state. Late embryogenesis abundant and heat shock proteins and reactive oxygen
scavenging enzymes were overrepresented in the dried state
