RESEARCH PAPER |
Hsp90 canalizes developmental perturbation
Laboratory of Molecular Biology, Agricultural University of Athens, Iera Odos 75, 118 55 Athens, Greece
To whom correspondence should be addressed. E-mail: phat{at}aua.gr
Stochastic processes are intrinsic phenomena that perturb developmental processes. However, the canalization process restricts the magnitude of perturbation and hence the magnitude of morphological variation during development. Heat-shock protein 90 (Hsp90) chaperones are a class of proteins stabilizing a network of ‘client’ proteins that are involved in diverse signal transduction pathways affecting development. Here it is reported that a reduction of Hsp90 gene dose creates canalization perturbations that affect many aspects of Arabidopsis development and results in a plethora of morphological alterations. Hence, Hsp90 restricts stochastic phenomena by minimizing perturbations, thereby canalizing development. It is also shown that morphogenesis is determined by three mutually inter-related parameters: genotype, environment, and time. Hsp90 is involved in the interaction of these three parameters which ultimately affect developmental processes. The amount of phenotypic variation upon the reduction of Hsp90 function could be perceived as adaptive and could have an impact on the evolutionary process.
Key words: Arabidopsis, genetic analysis, Hsp90, phenotypic variation, stochastic development
* Present address: Mount Sinai School of Medicine, Graduate School of Biological Sciences, One Gustave L. Levy Place, Box 1022, New York, NY 10029-6574, USA
Received 4 June 2007; Revised 23 July 2007 Accepted 24 July 2007