دراسة فسلجية تشريحية بايوكيميائية لنباتات مختلفة التحمل لسمية البورون ومعالجتها بأملاح الزنك بدلالة استجابة التجذير

الموضوعات

علوم بحتة وطبيعية

روابط وملفات

التعريف والنوع

رقم الوثيقة

fd8abc76-0eab-4e87-a958-f96d25c8b421

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل دكتوراة

نوع الملف

pdf text

أسماء الملفات

2005772_1.pdf

بيانات النشر

ترجمة العنوان

Physiological, Biochemical and Anatomical Study of Plants differing in their tolerance to boron toxicity and its recovery by Zinc salts, in terms of rooting response

ألقاب المؤلفين

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اللغة

Arabic

المصدر والدورية

اسم المصدر

دراسة فسلجية تشريحية بايوكيميائية لنباتات مختلفة التحمل لسمية البورون ومعالجتها بأملاح الزنك بدلالة استجابة التجذير

المحتوى والصفحات

عدد الصفحات

0

ترجمة الملخص

The role of Zinc in alleviating B-toxicity in terms of adventitious root formation (ARF) in cuttings of plants differing in their sensitivity to boron such as Mung bean (sensitive) ,Cucumber (Moderately tolerant ) and Tomato (tolerant) was studied. The toxic level of B in addition, to the promontory  conc. of Zn-salt was determined for each of the  above mentioned species. Three of Zn-salts were tested (sulphate, nitrate and chloride ) and the best promontory salt was Zinc sulfate in developing the highest number, of roots in addition to the best conc. of the same salt was 15,10,15 ppm for Mung bean, Cucumber and Tomato respectively, compared to other Zn-salt and their concentration . The toxic levels of boron were 200,300 and 400 µg/ml for Mung bean, Cucumber and Tomato respectively. These levels reduced growth parameters in terms of rooting response to 50% or beyond (55.16%, 50.83% and 53.49%) for Mung bean, Cucumber and Tomato compared to control. In addition to the localized toxic symptoms like necrotic spots at leaves edges of the above three species respectively. Boron detoxification occurred completely by supplying Zinc sulphate prior to toxic–B treatment (pre-treatment )in all species compared to its supply as post- treatment or simultaneously with toxic –B . The protective role of Zinc – sulphate was significantly enhanced the average of root number/cutting to its levels in control treatment  ( in absence of toxic – B)in all species under study. Toxic levels of B for the above species. caused a significant damage for plasma- membrane of leaf tissues through permeability perturbation in terms of EC% with increasing 111.05%, 50.015%  and 30.65 in cuttings of Mung bean, Cucumber and Tomato respectively. Whereas, in seedling (in presence of root system), the percentage of damage was declined to 83.74 ,42.59 and 9.91% when exposed to B-toxicity.These results confirms the sequostration mechanism of boron in roots exclusively rather than its transport to leaves .The toxic level of B caused  a reduction in IAA levels and a significant increase in IAA – oxidase activity. When Zinc sulphate was added, Zn caused an increase in IAA level and a decrease in IAA oxidase activity which  was not significantly different from the control. The initial concentration of Zn in plant cuttings was related to plant ability to the tolerance.The highest concentration was found in Tomato followed by Cucumber and Mung bean. The toxic level of B markedly reduced Zn concentration in the parts of plant cuttings. Treating these cuttings with Zn, increased Zn concentration to levels that were not statistically different from that in the control cuttings .The toxic conc. of B increased B level in all parts of cuttings but B levels values were  decreased down to its initial conc. when Zn was added .The tolerance mechanism of plant to toxic levels of B is increasing the uptake of Zn and decreasing the uptake of B. Glulathione (GSH), Ascorbic acid (ASA) content and the activity of catalase (CAT), Superoxide dismutase (SOD),Lipxygenase (LOX) and Ascorbate peroxidase (APX)enzymes were decreased in mung bean cuttings. On the other hand, they were increased by 124, 19.5, 75,55  and 12.3% in Cucumber and by 256 , 40.3 , 175, 1017 , 26  and 55% in Tomato respectively compared with the control treatment. Treatment with stress caused by the toxic level of boron by using ZnSO 4 before the addition of B increased GSH and ASA content and APX, CAT, and SOD activity ,Whereas , it lowered the activity of LOX in the studied plant species. Boron toxicity caused changes in tissue measurements in leaves of Mung bean, Cucumber and Tomato cuttings, led to decline of leaves thickens, midrib, spongy layer, bundle length. In addition an increases of palisade layer thickens , bundle width in Mung bean and  Cucumber, and the increase of all the above parameters in  Tomato leaf cuttings. The toxic level of boron reduced the thickens of the hypocotyls ,cortex as wells vascular bundle number  in Mung bean and  Cucumber. However, the measurements of vascular bundle increased in Mung bean but decreased in Cucumber, whereas in Tomato all the above measurements were increased. On the other hand, Zn supply was improved the anatomical characteristics for leaves and basal part of cuttings. This means that Zn was lowering the negative effect due  to boron stress in anatomical structures of these plants.

إشراف وإعداد

الإشراف

عبد عون هاشم علوان, عبدالله إبراهيم شهيد

الإعداد

خالد علي حسين اليساري

الاقتباسات الببليوغرافية