Linking Hsp90 function to micro-environmental and stochastic variation in floralorgans of Iris pumila L.

Hsp90 is an environmentally responsive molecular chaperone that was found to play a key role in buffering against genetic and non-genetic perturbations in the model organisms Arabidopsis and Drosophila . Here we analyzed the buffering capacity of Hsp90 against two kinds of non-genetic factors - stochastic noise and micro-environmental varia- tion of floral organ traits in naturally growing Iris pumila plants. We found no statistical association between the endog- enous level of Hsp90 and the floral organ radial symmetry produced by stochastic developmental noise. Conversely, floral organ plasticity in response to micro-environmental variation tended to be greater with decrease in Hsp90b isoform expression.