Effects of Chloramphenicol on Pigmentation, Proline Accumulation and Chlorophyll Fluorescence of Maize (Zea mays) Seedlings

Effects of Chloramphenicol (CAP) on the maize (Zea mays) seedlings were investigated using some physiological indexes like the pigmentation, proline accumulation and the fast rise chlorophyll a fluorescence. This study shows that chlorophyll synthesis of maize seedling is stimulated by CAP at 50 and 100 mg/L but inhibited by CAP at 250 mg/L. Proline content was slightly altered under stress of 50 and 100 mg/L CAP and increased markedly under stress of 250 mg/L CAP, suggesting that the cell membrane structure is only affected in the presence of high level of CAP. The maximum quantum yield for primary photochemistry (Fv/Fm) and performance index on absorption basis (PIABS) showed the same change pattern as the chlorophyll content in response to CAP treatment, indicating that photosystemII (PSII) function was enhanced by CAP at 50 and 100 mg/L but significantly inhibited at 250 mg/L. However, the decreasing of carotenoid content, enery flux and electron flux through PSII reaction centers (RCs) with increasing CAP concentration shows that CAP at all experimental concentrations exerts adverse effect on pigment synthesis other than chlorophyll photosynthetic physiology that can not be indicated by Fv/Fm or PIABS. (C) 2011 Friends Science Publishers