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Master Degree Theses

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20142
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Subject: Agricultural Biotechnology ×

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    ThesisItemOpen Access
    TRANSCRIPTOME ANALYSIS OF PIGEON PEA (Cajanus cajan L.) DURING VARIOUS TEMPERATURE, DROUGHT AND HEAVY METAL STRESSES
    (PLANT MOLECULAR BIOLOGY & BIOTECHNOLOGY DEPT., N. M. COLLEGE OF AGRICULTURE, NAVSARI AGRICULTURAL UNIVERSITY, NAVSARI, 2014-03) Radadiya, Nidhi G.; Mahatma, Lalit
    During 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.
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    ThesisItemOpen Access
    Cross Talk of Various Genes of Phenylpropanoid Pathway in Castor (Ricinus Communis L.) During Multiple Abiotic Stress
    (LANT MOLECULAR BIOLOGY AND BIOTECHNOLOGY DEPT., N.M.COLLEGE OF AGRICULTURE, NAVSARI AGRICULTURAL UNIVERSITY, NAVSARI, 2014-02) DOBARIYA, BHAVIKABEN R.; Singh, Diwakar
    Castor (Ricinus communis L.) is an important non-edible oilseed crop of india. The salt and drought are most serious factors of castor affecting its plant population and yield. Understanding resistance/ susceptibility in castor during salt and drought would facilitate the development of new control strategies and the identification of host factors required for resistance responses against salt and drought stress. Therefore, the present investigation was studied during salt and drought stress in correlation with phenylpropanoid pathway at molecular and biochemical level in the leaves and roots of castor (48-1) at 0, 24, 48 and 72 hour after treatment (hat). Phenol profiling using HPTLC showed the presence of two phenolic acids i.e. caffeic acid and ferulic acid, which were observed in leaves and roots of castor during salt and drought stress and found highest during salt stress at 72 hat at 200 mM NaCl concentration in leaves and roots of castor. These phenolic acids were also highest at same time point with -0.5 MPa water potential in leaves and roots of castor during drought stress. Gallic acid was observed only in salt treated roots at 24 hat and in drought treated roots at 24, 48 and 72 hat. Gallic acid was not observed in salt and drought treated leaves as well as in non treated control. Proline content and total protein were studied during salt and drought stress. Increasing proline content at 48 hat was positively correlated with increasing salt and drought stress. Total protein increased during salt and drought stress and it was maximum at 72 hat. The polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), Cinnamate 4 hydroxylase (C4H) and p-Coumaric acid 3-hydroxylase (C3H) activities were studied in leaves and roots of castor during salt and drought stress. The PPO enzyme activity increased in leaves and roots at 24 hat and 72 hat, respectively during salt stress at 200 mM. Similarly, during drought stress the PPO activity increased in leaves and roots at 48 hat with -0.5 MPa water potential. The PAL activity increased upto 72 hat in leaves and roots with different NaCl concentration and at different water potentials. C4H activity was recorded highest at 72 and 24 hat in salt treated leaves and roots, respectively and it was highest at 72 hat in drought treated leaves as well as roots. C3H enzyme showed higher activity at 24 hat in leaves and at 72 hat in roots with 200 mM NaCl concentration. Similarly, increasing of C3H activity was also observed at 72 hat with drought stress as compared to control. Expression analysis was carried out using RT-PCR with PAL, C4H1 and C4H2 gene specific primers. The expression of PAL gene and C4H-2 gene at different salt concentration and at different water potentials was appreciably higher at 72 hat than 24 and 48 hat as compared to control. The gene expression of C4H-1 was highest at 48 hat in leaves and roots with salt stress whereas it was highest at 72 hat in leaves and roots with drought stress. Overall, salt and drought stress exhibited higher expression of PAL, C4H1 and C4H2 genes, which are genes of phenylpropanoid pathway and responsible for defense against stress. These results suggest the critical role of phenylpropanoid pathway in imparting resistance to castor against multiple abiotic stress, viz., salt and drought stress.