A proteomic approach to investigating the promotive effects of brassinolide on root growth of rice seedlings

Abstract

Brassinolide influenced rice (Oryza sativa L.) root growth in a concentration-dependent manner. Roots grown in 0.1 nmol/L BL were 28% longer than those in the control. On the other hand, the roots grown in 1000 nmol/L BL were 65% shorter in comparison with those in the control. To investigate how BL influences rice root growth, proteome analysis techniques were applied. After BL treatments, total proteins from rice root were extracted separately. Extracted proteins were separated by two-dimensional polyacrylamide gel electrophoresis and analyzed using an automated protein sequencer and mass spectrometer. There were 33 proteins that showed differences in the accumulation levels as a result of treatments with BL. Proteins related to stress tolerance, enzymes, and cell structure were mainly found in the root. There were many proteins regulated by other hormone or light also. Results suggest that the physiologic functions of these proteins detected using powerful proteome analysis are implicated in root elongation triggered by BL. High-level brassinosteriod (BR) indicated that IAA amidohydrolase, which can release active IAA from IAA pool was increased, and the IAA level was so high that the root length was inhibited.

Key words： rice; proteomics; brassinolide; root growth

Acknowledgements

This work was financially supported by the Foundation of Education Department of Hebei Province, China (Grant No. z2010148).

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