Retrotransposons and siRNA have a role in the evolution of desiccation tolerance leading to resurrection of the plant Craterostigma plantagineum.
* Craterostigma plantagineum can lose up to 96% of its water content but fully recover within hours after rehydration. The callus tissue of the plant becomes desiccation tolerant upon pre-incubation with abscisic acid (ABA). In callus and vegetative organs, ABA addition and water depletion induce a set of dehydration-responsive genes. * Previously, activation tagging led to the isolation of Craterostigma desiccation tolerant (CDT-1), a dehydration-related ABA-inducible gene which renders callus desiccation tolerant without ABA pre-treatment. This gene belongs to a family of retroelements, members of which are inducible by dehydration. * Craterostigma plantagineum transformation with mutated versions of CDT-1 indicated that protein is not required for the induction of callus desiccation tolerance. Northern analysis and protoplast transfection indicated that CDT-1 directs the synthesis of a double-stranded 21-bp short interfering RNA (siRNA), which opens the metabolic pathway for desiccation tolerance. * Via transposition, these retroelements have progressively increased the capacity of the species to synthesize siRNA and thus recover after dehydration. This may be a case of evolution towards the acquisition of a new trait, stimulated by the environment acting directly on intra-genomic DNA replication.
Hilbricht
Tobias
T
Max-Planck-Institut fur Züchtungsforschung, Carl-von-Linne Weg 10, D-50829 Köln, Germany.
Varotto
Serena
S
Dipartimento di Agronomia Ambientale e Produzione Vegetale, University of Padova, Agripolis-Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
Sgaramella
Vittorio
V
Fondazione Parco Tecnologico Padano, CERSA, via Einstein - Località Cascina Codazza, 26900 Lodi, Italy.
Bartels
Dorothea
D
Molekulare Physiologie und Biotecnologie der Pflanzen, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
Salamini
Francesco
F
Fondazione Parco Tecnologico Padano, CERSA, via Einstein - Località Cascina Codazza, 26900 Lodi, Italy.
Furini
Antonella
A
Dipartimento Scientifico e Tecnologico, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
D000040:Abscisic Acid / Q000378:metabolism; D000220:Adaptation, Biological; D005075:Biological Evolution; D032181:Craterostigma / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D003890:Desiccation; D004777:Environment; D044127:Epigenesis, Genetic; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D010940:Plant Proteins / Q000235:genetics; D014176:Protein Biosynthesis; D034741:RNA, Small Interfering / Q000502:physiology*; D018626:Retroelements / Q000502:physiology*; D014170:Transformation, Genetic
C107112:CDT-1 protein, Craterostigma plantagineum; D010940:Plant Proteins; D034741:RNA, Small Interfering; D018626:Retroelements; D000040:Abscisic Acid