Role of jasmonic acid in improving tolerance of rapeseed (Brassica napus L.) to Cd toxicity / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The well-known detrimental effects of cadmium (Cd) on plants are chloroplast destruction, photosynthetic pigment inhibition, imbalance of essential plant nutrients, and membrane damage. Jasmonic acid (JA) is an alleviator against different stresses such as salinity and drought. However, the functional attributes of JA in plants such as the interactive effects of JA application and Cd on rapeseed in response to heavy metal stress remain unclear. JA at 50 µmol/L was observed in literature to have senescence effects in plants. In the present study, 25 µmol/L JA is observed to be a "stress ameliorating molecule" by improving the tolerance of rapeseed plants to Cd toxicity. JA reduces the Cd uptake in the leaves, thereby reducing membrane damage and malondialdehyde content and increasing the essential nutrient uptake. Furthermore, JA shields the chloroplast against the damaging effects of Cd, thereby increasing gas exchange and photosynthetic pigments. Moreover, JA modulates the antioxidant enzyme activity to strengthen the internal defense system. Our results demonstrate the function of JA in alleviating Cd toxicity and its underlying mechanism. Moreover, JA attenuates the damage of Cd to plants. This study enriches our knowledge regarding the use of and protection provided by JA in Cd stress.

Interaction of palladium inorganic salt and organic complex with glutathione content of liver homogenate

Glutathione is an essential antioxidant of living organism that provides a primary protection against metals toxicity. A significant amount of glutathione is present in blood erythrocytes, plasma and liver hepatocytes to protect them from oxidative damage from both external and internal oxidants. Metalo-element palladium has numerous pharmacological, clinical and toxicological compensations, like palladium is used as anti-viral, anti-bacterial, neuroprotective and anti-tumor agent. However studies have also indicated some mild to serious toxic effects of palladium metallo-elements. In the presence study the interaction of palladium inorganic salt and organic complex with glutathione [GSH] content of liver homogenate was examined spectro-photometrically. 20% [w/v] liver homogenate was prepared of the collected liver of rabbit in 5% TCA [tri-chloro-acetic acid] solution and 1mm EDTA, using a potter-eveljhem homogenizer with motor driven Teflon pestle. The GSH content quantification was carried out by Elman's method. Our finding showed that there was a depletion of GSH content by both palladium inorganic salts and organic complexes, concentrations wise as well as with time elapse as level of GSH content decrease from [43.6% to 72.62%] with Palladium Nitrate and from [24.09 to 59.5%] with Bis-benzonitrile Palladium II Chloride as compared to control, and further dropped with time incubation from 0-90 minutes from [49.7 to 87.1%], with Palladium Nitrate and from [29.3% to 67.6%] respectively. The result showed that the effect of both inorganic salt of palladium was more enhanced as compare to its organic complex. It was suggested from our finding that the depletion in the glutathione content of liver homogenate may be due to oxidation of glutathione or due to glutathione metal abduct formation by both inorganic salt and organic complex of palladium. This study in situ is a model of in vivo

role of Glutathione, Cysteine and D-Penicillamine in exchanging Palladium and Vanadium metals from albumin metal complex

Thiol groups are extensively present across biological systems being found in range of small molecules [e.g. Glutathione, Homo-cysteine] and proteins [e.g. albumin, haemo-globin]. Albumin is considered to be a major thiol containing protein present in circulating Plasma. Albumin contains a single thiolate group located at cysteine-34[cys-34] at its active site. Albumin also binds a wide variety of metals and metals complexes at various sites around the protein. Usually heavy metals are preferentially attached with the thiol group of albumin. The binding of heavy metals at cys-34 provides a mechanism by which the residence time of potentially toxic species in the body can be increased. In this research we have assessed the oxidative modification of and metal binding capacity of cys-34 with heavy metals Palladium and Vanadium to investigate the ease with which it is possible to effect disulfide-thiol exchange at this sites/or remove a metal bound at this position. Both the metals were treated with albumin and then the albumin metals [Pd and V] complexes were treated with small thoil molecules like Glutathione, Cysteine and D-Penicillamine. Our finding showed that the albumin thiol group retained the metals with itself by forming some strong bonding with the Thiols group, it is concluded from this finding that if by chance both the metals enter the living system; strongly disturb the chemistry and physiological function of this bio-molecule