Investigation of the effect of herbicide amiprophos methyl on spindle formation and proteome change in maize by immunofluorescence and proteomic technique

Abstract

To investigate the mechanism with which the phosphoric amide herbicide works, the effects of microtubule inhibiting herbicide amiprophos methyl (APM) on microtubule (MT) and proteomic were analyzed in the meristem cell and the mesocotyl, root, and leaves of maize. The immunofluorescence analysis showed that APM inhibited the spindle assembly in the cells during metaphase and anaphase when root meristems were treated with 10 μM APM for 12 h. Condensation of spindle, unequal spindle and multipolar spindle were observed, resulting in the formation of chromosome condensation in metaphase and unequal segregation of chormosome in anaphase. The frequency of these abnormal cells increased with the duration of treatment. Proteomics analysis revealed that 28 protein spots were altered, including the appearance of 15 new protein spots and the disappearance of 13 pre-existing proteins in the mesocotyl, root, and leaves. MALDI-TOF MS analysis of 10 protein spots has identified as cold acclimation protein WCOR615, ubiquitin, maturase K, an ubiquitin-like protein, Cytochrome P450 monooxygenase in mesocotyl, Ferrdoxins, 2,4 Dienoyl- CoA reductase in root, ATP-dependent protease, retrotransposn in leaves and an unnamed protein, which were involved in diverse biological processes, including protein synthesis and degradation, mRNA folding and splicing, cell cycle progression and signal transduction, energy metabolism and defense response. These results suggest that the herbicide APM is a specific chemical that interrupts microtubule dynamics and influences the expression of a number of proteins, which may be served as putative biochemical markers to monitor the toxicity of the herbicide in plants. © 2011 The Japan Mendel Society.