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Mechanism Of NO-mediated In Response To Iron Deficiency Of The Malus Xiaojinensis

Posted on:2017-09-12Degree:MasterType:Thesis
Country:ChinaCandidate:Y N LiFull Text:PDF
GTID:2310330512956043Subject:Plant Nutrition
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Iron (Fe) is essential for the survival and proliferation of all plants. But the availability of Fe is very low in soil, especially in calcareous soil, iron deficiency becomes one of major limiting factors affecting crop production and quality. Nitric oxide, as a signal molecular in plant, is closely related to Fe metabolism in plants. In the study, Malus xiaojinensis were used to investigate the effects of exogenous nitric oxide on physiological metabolism and molecular mechanism in Malus xiaojinensis under iron-deficiency stress. The results were as follows:1. The results of different processing conditions NO fluorescence intensity and positioning analysis showed that the iron deficiency stress can increase plant root NO fluorescence intensity, which proved that the strength of the plant root tip of NO induced by iron deficiency stress. The root area and NO fluorescence root primordium fluorescence intensity can significantly enhance with the exogenous NO treatment. The results of NO fluorescence intensity and positioning analysis showed the root NO fluorescence in Malus xiaojinensis induced by iron-deficiency and the effects of exogenous NO.2. Under severe iron-deficient stress, Malus xiaojinensis s root began to brunissement. The root TTC activity in Malus xiaojinensis was reduced under iron-deficient, and the root activity of FCR increased. The chlorophyll content and net photosynthetic rate decreased. With exogenous NO processing, the chlorosis of leaves has been improved and the root growth became normal, liked the TTC activity increased and the root activity of FCR reduced. Also the chlorophyll content and net photosynthetic rate became normal. Which indicated that NO might deteriorate the harm that iron deficiency caused and showed the protective effects on iron-deficient plants.3. Iron-deficient decreased the activities antioxidant enzymes (SOD?POD?CAT) and respiration enzymes(PPO?AAO). The application of exogenous NO increased activities of SOD?POD and CAT, it could improve the ability of scavenging reactive oxygen species, NO expressed extenuating effects on oxidative stress caused by iron deficiency. The activities of PPO and AAO also raised, thereby maintain normal growth and development of plants.4. The Northern blot proved that the iron-deficienct related genes AKR2B, MxMyb1 strengthen specific expression at the root of Malus xiaojinensis. The application of exogenous NO the gene specificity of AKR2B?MxMyb1 were stormier than a single low iron processing. It was deduced that NO as a signal molecular under the stress of low iron for iron for iron related molecular and gene specific expression have induced effect.
Keywords/Search Tags:Malus xiaojinensis, Iron, Nitric oxide, photosynthesis
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