Individual and combined effect of mercury and manganese on phenol and proline content in leaf and stem of mungbean seedlings.

Mungbean (Vigna radiata L. Wilczelk cv. Pusa Baisakhi seedlings were raised in individual (0, 1, 10, 100 and 1000 ppm) and combined solutions (1 : 1, 10: 1, 1: 0 ppm Hg : Mn) of mercury and manganese for 6 days. Phenol and proline were found to accumulate in leaves in response to treatment with heavy metals. The magnitude of accumulation correlated with concentration of metals. However, a reverse trend was noticed in stem for phenol. Accumulation of phenol in response to heavy metal treatment was organ specific and occurred at higher rate in plant parts, which faced the stress mostly. However, accumulation of proline helped the plant to survive stress situation. In combined solutions, amelioration of mercurial toxicity by manganese was recorded.

Amelioration of mercurial toxicity by manganese. I. A case study in mung bean seedling.

Mercury, a non essential element renders inhibitory effect on many physiological activities of plants even at a low concentration. Plants absorb "Hg" from soil through root system. Manganese, an essential element has been found to counter the inhibitory effect of mercury mostly by preventing it's uptake from soil. Mung bean (Vigna radiata L. Wilczek) cv. Pusa Baisakhi grown in individual (1, 10, 100 and 1000 ppm) solution of Hg and Mn showed varied uptake of these heavy metals. However, in combined solutions (1 : 1, 10 : 1 and 1 : 10 ppm Hg : Mn), mercury uptake was mostly prevented in presence of 10 ppm Mn, indicating it's ameliorating effect.