Expression data from 16H and 24H post-stratification seeds from Arapidopsis thaliana pme36-1 and Col0 lines

Pectins localize in the primary cell wall and consist of multiblock co?polymers among which homogalacturonan (HG) is the simplest and most abundant form. Methylesterification pattern of HG is tuned by pectin methylesterases (PMEs), which activity is itself controlled by specific inhibitors or PMEIs. PME?mediated regulation of HG methylesterification plays a major role in controlling several developmental processes, including seed germination and dark grown hypocotyl elongation. Arabidopsis PME36 is preferentially expressed during the late stages of silique development and, using the knock?out mutant pme36-1, we showed that PME36 is required to implement the characteristic pattern of demethylesterified pectins in mature seed. However, although this pattern was strongly impaired in pme36-1 mature seed, no phenotypical change was observed in the mutant during seed germination and seedling dark growth, suggesting the existence of a compensatory mechanism overcoming the defect in pectin demethylesterification. To get insight into this mechanism, a transcriptomic analysis by microarrays was performed on pme36-1 and Col0 wild-type, in seed at two early stages of germination, preceding tegument rupture: 16 hours and 24 hours after transfer from cold room (stratification) to dark growth condition. Affymetrix four-arrays strips (Arabidopsis Gene 1,1 ST Array strip) were used to analyse four replicates of 16H and 24H post-stratification seeds.