Mahatma, LalitRadadiya, Nidhi G.2017-02-212017-02-212014-03http://krishikosh.egranth.ac.in/handle/1/5810002032During the present investigation, different biochemical and molecular parameters in pigeon pea were analyzed during various temperature, drought and heavy metal stress conditions. Over all maximum activities of Glutathione-S-transferase was observed in the leaves and roots exposed to the 7 % PEG stress followed by 500 μmol CdCl2 in 3 days after the exposure to the stress. The data suggested that the Glutathione-S-transferase is a principle enzyme expressed in response to the drought and heavy metal stress. Expression of the enzyme was less in the higher concentration of PEG (15%) and CdCl2 (500 μmol). This may be due to the toxicity of these at the higher concentration. Maximum expression of glutathione reductase was observed in 650 μmol CdCl2 in 3 days after the exposure to the stress followed by the 15 % PEG exposure. Data suggested that the glutathione reductase is also one of the key enzyme expressed in response to the drought and heavy metal stress, however, is capable to tolerate higher concentration of PEG and CdCl2 than GST. Maximum expression of ascorbate peroxidase was observed in 7 per cent PEG followed by 15 per cent PEG and chilling stress at 3 days after the exposure to the stress. Data suggested that the ascorbate peroxidase is also a key enzyme for the drought, however, it is also found in the response to the chilling stress. The Glycine betaine (GB) content was higher in drought stress compared to other stresses and control seedlings after 3 days of stress whereas, in chilling stress the GB content was reached up to 208.09 μmol. In heavy metal stress GB level was increased up to 144.06 μmol and 159.86 μmol at 500 μmol and 650 μmol CdCl2 concentration respectively. After 6 days of all stresses seedlings were almost maintain the GB level which noted at 3 days after stress. Among the different polyamines, putrescine was detected in all stressed seedlings of pigeon pea at all the stages of analysis whereas cadavarine was detected in only heavy metal and 15% PEG treated seedlings leaves. Spramine and spermidine were not detected in heavy metal stress but detected in drought and cold stress. In drought stress treatment the per cent area of putrescine was higher at the 3 days after treatment which further decreased slightly at 6 days after treatment. Heavy metal and chilling stress also showed the higher putrescine level than the control seedlings leaves. Spermidine was also detected in drought and chilling stress, however, was not detected in heavy metal stress. Cadavarine was detected in heavy metal stress. Maximum expression of SAMs gene in the leaves were observed at 3 days after drought stress with 15% PEG that is increased by 6.543 fold as compared to control. Similarly, maximum SAMs gene expression in the roots were observed at the same time period and same water potential that is increased by 2.428 fold as compared to control. Conversely, expression of SAMs gene were not detected in leaves and roots at cadmium stress but transcripts were down regulated as compared to the control. Expression of SAMs gene was also studied in leaves and roots at chilling stress (10oC). SAMs gene expression were increased by 6.32 fold in leaves and 2.028 fold in roots at 3 days after stress. After 6 days of stress expression of SAMs gene observed that is increased by 1.537 fold in leaves and 1.064 fold in roots as compared to the control but it was lower than expression of SAMs gene which noted at the 3 days after stress.ennullThesis