الفهرس 
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Abstract
The present work aimed to studying the efficiency of putrescine in alleviation the hard effect of heat stress on growth and some primary and secondary metabolites of Trigonella seeds. And test the possibility to ameliorate the harmful effects induced by temperature stress on Trigonella foenum gracum plant upon putrescine treatment. Trigonella seeds presoaked in 5m M of putrescine for 2 hours, then the seeds germinated for 5 days under normal environmental conditions. After 5 days of growth, the seedlings were exposed to different temperature degrees at 15°C, 25°C, 35°C and 40°C for 4 hours. The seedlings were left to grow till the end of the season. Samples were collected after 17 days (seedling stage), 45 days (vegetative stage) and 120 days (fruiting stage). The obtained results are summarized as follows: The data indicated that the temperature at 15°C and 35°C resulted in a significant decrease in germination percentage by 36.6% at 35°C. While a significant increase in the percentage was achieved after 17 days of growth at 35°C by applying putrescine (5m M) compared to control. The study showed that, after 17 and 45 days of growth, the length, fresh and dry weights of roots and shoots of Trigonella plant were decreased at the temperature stress degrees at 15°C and 35°C. Furthermore, the results showed an increase in all mentioned growth parameters by applying singly and combined treatment of putrescine (5m M) compared to control. Moreover, the data showed that applying of putrescine on the stressed samples was effective in alleviating the harmful effect of temperature stress. The results showed that, the photosynthetic efficiency measured as fluorescence was significantly decreased after 45 days of temperature- stressed Trigonella plant. Also, the content of chlorophyll a, b and carotenoids were decreased at 15°C and 35°C of temperature stress degrees compared to control. A single or combined treatment of putrescine (5m M) resulted in increasing the photosynthetic efficiency and the content of photosynthetic pigments compared to control. Moreover, plant pretreatment with putrescine alone had the highest effect in reducing the harmful effect of temperature stress. Antioxidant enzymes activities of seedling of growth showed that, there was a significant increase in the activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) enzymes of stressed Trigonella cultivar at both temperature stress degrees (15°C and 35°C). In general, pretreatment of putrescine (5m M) as sole or combined with temperature stress induced a marked reduction of antioxidant enzymes activity CAT, POD and SOD in leaves of plant as compared with the corresponding temperature degrees. The present study showed that, the temperature stress at 15°C and 35°C significantly decreased the content of total soluble protein and carbohydrates of shoot and root of Trigonella plant after 17 days of growth. While pretreatment with putrescine (5m M) as sole or combined with temperature stress significantly increased the contents of both soluble protein and soluble sugars relative to the control. While after 45 days of growth, the content of total soluble protein and carbohydrates in root and shoot of Trigonella plant were increased at temperature stress at 15°C and 35°C, but the content of samples pretreated with putrescine (5m M) as sole or combined with temperature was decreased. The content of MDA was markedly increased in the leaves of temperature – stressed plant after 17 and 45 days of growth at both temperature stress degrees, on the other hand pretreatment with putrescine had an alleviating effect of MDA values as compared with the corresponding stressed samples. Temperature stress at 15°C and 35°C had a significant effect on increasing proline content in the shoots of Trigonella plant compared with control after 17 and 45 days of growth. While pretreatment with putrescine reduced the proline content compared with stressed samples. The results showed that, after 17 and 45 days’ growth of the plant, the content of alkaloids were significantly decreased at both temperature stress degrees at 15°C and 35°C compared with control. In general, pretreatment of putrescine (5m M) as sole or combined with temperature stress at 15°C and 35°C induced a marked increase in alkaloid content of shoots as compared with the corresponding temperature stressed samples. The data indicated that after 17 and 45 days of growth, the content of phenols were increased in response to temperature stress at 15°C and 35°C in the shoots of Trigonella plant compared with control. While pretreatment with putrescine (5m M) led to a reduction of phenols content compared to stressed samples. The results showed that after 30 days of growth, there was a marked effect on ultrastructure of Trigonella leaves especially on chloroplast, nucleus and intercellular spaces in response to temperature stress. Firstly, chloroplast has numerous starch granules, developed granal stacks interconnected by stromal thylakoids in control samples. When Trigonella leaves exposed to low temperature stress at 15ºC occur distortion and reduction in the size and number of starch granules in the chloroplast, while exposure plant leaves to high temperature stress at 35ºC led to separation of plasma membrane from cell wall indicating plasmolysis compared to control samples. Application of putrescine (5m M) lowered the harmful effects induced by low and high temperature, the chloroplast retained its uniformity with wellorganized grana and becomes close to the cell wall. Secondly, the nucleus of Trigonella leaves has clear chromatin and two nucleoli in control samples. When Trigonella leaves exposed to low and high temperature stress at 15ºC and 35ºC caused deformation shape with fragmented chromatin and indefinite shape of nucleoli compared to control. Application of putrescine (5m M), the nucleus regained its structure and appeared with well-defined nucleoli compared with stressed samples. Thirdly, when Trigonella leaves exposed to low and high temperature stress at 15ºC and 35ºC caused discontinuity in the plasma membrane and precipitation of osmophilic substance in the intercellular spaces compared with control samples. Application of putrescine (5m M) retained the intercellular spaces to their normal shape compared with stressed samples. The results showed that after 120 days of growth, there was a significant decrease in the measured yield parameters of the plant (number of pod per plant, number of seeds per pod, weight of pod and weight of 1000 seeds) in response to temperature stress at 15°C, 35°C and 40°C compared with control. While pretreatment with putrescine (5m M) single and combined significantly increased these parameters compared with stressed samples. After 120 days of growth, the results showed a significant reduction in the content of total soluble proteins and sugars of the produced Trigonella seeds as a result of temperature stress at 15°C,35°C and 40°C compared with control. However, pretreatment with putrescine sole or combined increased the content of both sugars and proteins in Trigonella seeds compared with stressed samples. It was found that after 120 of growth, the content of total free amino acids of Trigonella seeds were increased significantly at temperature stress at 15°C and 35°C compared with control. Also amino acid content was increased when seeds pretreated with putrescine (5m M) compared with stressed samples. The protein profile of Trigonella yielded seeds revealed the appearance of five newly formed polypeptides having molecular weight of 44, 72, 31, 43 and 58 KDa in response to temperature stress at 15°C and 35°C. On the other hand, pretreatment with putrescine resulted in disappearance of three polypeptides with molecular weight of 43, 31 and 20 KDa present in the control. The fatty acids content of Trigonella yielded seeds showed that the percentage of saturated fatty acids were higher than percentage of unsaturated fatty acids in response to temperature stress at 15°C and 35°C singly. However, pretreatment with putrescine combined with temperature stress increased percentage of unsaturated fatty acids compared with counterpart in temperature stress alone.