Alterations in the expression of genes for tubulin and stress in two Arabidopsis auxin mutants during simulated microgravity

The effect of microgravity on the expression of genes for tubulin, stress and aging in Arabidopsis seedlings from wild-type, and the auxinic mutants aux 1 and eir/pin2 is reported. Simulated microgravity was produced through the Random Positioning Machine (RPM). The results showed that the tubulin genes TUA4, TUA6 and TUB2, in plants subjected to μg, showed a peak of expression at 3h in the wild-type, whereas in the mutants it was delayed to 6h. The microgravity treatment tested on the expression of stress genes FeSOD1 and CAT3 showed ony a significant increase of senescence SAG12 showed increased expression in the wild-type starting at 3h, whereas in the mutant a significant increase was seen only at 24h. From the collected data we conclude that auxin transport and action should be involved in tubulin synthesis, stress, and the senescence process.