The active oxygen free radical the influence which grows to the tobacco

　The free radical (flee radical, fr) is refers to does not have the unpaired electron member, the atomic group, the atom or the ion. in fr the oxygen free radical (oxygen free radicals, ofr) has the close relationship with organism damage. ofr including o2. - and hydroxyl free radical (ho) and so on, moreover, active oxygen like h202 and singlet oxygen (1o2),Although is not fr, but its oxidation is also strong, the process responded that may form ofr or involve fr to respond, therefore often is also listed as ofr; Generalized ofr also includes the fats (rh) peroxidation intermediary product r, roo and rooh and so on material [4] which is livelier than the oxygen.

 In the leaf tobacco production process will have the drought and the low temperature frequently, regardless of under the high temperature or the low temperature coercion, in the smoke seedling the endocardial oxidation inhibitors content will obviously drop, the cell membrane penetrability will increase, 02. - the massive productions, the accumulation membrane fat peroxidation product (mda), and increases along with the low temperature coercion times extension, the membrane fat peroxidation function intensifies, the active oxygen production and the elimination are unbalanced, thus has the adverse effect to the smoke seedlings growth and the leaf tobacco quality. Moreover, the leaf tobacco roasting is similarly a person for the drought and the high temperature coercion process, in the leaf tobacco the active oxygens accumulation causes the membrane fat peroxidation function, has the possibility to affect the roasting period leaf tobacco the senile advancement, after then the influence roasts, leaf tobacco chemical composition. In addition, when the tobacco will be under other adverse circumstance coercion like the pathogen to invade dyes and so on, in the tobacco massively will also produce ofr, will cause the membrane fat peroxidation and the membrane penetrability loses, causes the metabolic disorder to cause organism to receive injures [5,6].

　Experiments [7,8] to prove, regardless of produces with the suitable density combinations ferrous sulfate and the h202 response ho, with the certain densitys h202 processing tobacco aerosol cell, can observe the obvious cell chromatin directly to condense the morphological character which, model and so on cytoplasm shrinkage and cell nucleus disintegration cells perish weakly, Meanwhile observes on the tobacco aerosol cell dna agarose gel electrophoresis atlas, because nucleus dna has the rule in the entosthoblast between the stepped banding which degrades produces, indicated that ho and h202 can induce the tobacco cell to perish weakly.

In cigarette haze ofr and hazardous nature

Studies [9,10] to indicate that in the cigarette haze includes many kinds of harmful o 2.1, ho and alkoxyl fr, although these fr life is short, but its hazardous nature actually by far is bigger than the smoke alkali. Through smoking, the human body has the possibility to attract person these fr. These high potencys fr is very freely short in vitro survival time, but once inhales the human body, will consume in human bodys oxidation inhibitor, Studies [9,10] to indicate that in the cigarette haze includes many kinds of harmful o 2.1, ho and alkoxyl fr, although these fr life is short, but its hazardous nature actually by far is bigger than the smoke alkali. Through smoking, the human body has the possibility to attract person these fr. These high potencys fr is very freely short in vitro survival time, but once inhales the human body, will consume in human bodys oxidation inhibitor,

　In the normal condition, in the human body the fr production and eliminates is at one state of equilibrium, once fr will have excessively many or the oxidation resistance ability drops will cause balanced being out of balance. Looked from the molecular level that ofr has the widespread destructive function to the biological macromolecule structure, may cause the basic group change either the loss, the dna break or crossing linking, the cancer gene activation and the deactivation to the stone fruits archery target function and so on, Specially the chromatin located at entosthoblast between histone ingredient is ofr attack essential target [13]. Cigarette haze fr in human bodys function result is:①Causes the dna damage to change suddenly, the biomembrane oxidation damage and the neurotrosis and so on;②Possibly activates and produces more free radical like o in vivo 2.1 and ho.

In tobacco resistance (sickness) aspect application

In the transgene tobacco, the alfalfa, the potato and the cotton, the chloroplast sod excessive expression, enhanced these plants to oxidative stress tolerant [14]; Will exist mn-sod leads the person tobacco, alfalfas chloroplast after the line plastochondria, its transgene adult plant to the ozone and the arid coercions resistance strengthens [15]; The transgene tobacco chisod excessive expression, enhanced the adult plant to freeze injury tolerant [16,17]. Studies [18] to indicate that will plan the blue mustard (aba-bidopsis thaliana) the fe-sod gene transformation tobacco (nicotiana tabacum cv petit havana sr1) the chloroplast, the fe-sod excessive expression can strengthen the chloroplast protoplasmic membrane and the photosynthesis system to mv (methyl viologen, methyl viologen, namely “paraquat”) and high salty peroxidation coercion resistance.

　Studies [19] to discover that pea (pisum sativum) cu, zn-sod gene in tobacco (n tabacum cv.xanthi) in chloroplast moderate increase expression (about 2 times), smoke has the certain extent resistance to the adverse circumstance, at glare and under the cold environment, transgene smoke is higher than in growth any stage the non-transgene smoke photosynthesis speed; The transgene tobacco is right “the paraquat” the patience can enhance (1.2lmoll-1) similarly, and causes to the high light the light suppresses not sensitively. In “the paraquat” or the cadmium creates under the oxidative stress condition, clones from paxillus involutus obtains the pisod product to be able to save the sod mutant tobacco to transform [5] effectively. in n.plumbaginifolia mn-sod in n.tabacum in cv.pbd6 chloroplast or line plastochondria excessive expression, Obviously reduced the ofr quantity which “the paraquat” (1.2moll-1) and the o3 oxidative stress produces, enhanced smoke to adverse circumstance patient [20]. In addition it is reported that [21]: Prevents and controls the tobacco climate scab with sod (weather fleck), the field spurts executes 0.04u/mlsod, sickness refers to against effect to reach 74.49%.

In reduces in the cigarette haze free radical the application

In cigarette hazes fr divides into gas phase fr and solid phase fr[22] generally. Solid phase fr may use the ordinary vinegar filament to filter the mouth filtration, thus the dispelling cigarette haze fr research mainly concentrates in the gas phase fr aspect. [23] and so on hersh said that joins one kind of enzyme catalysis medicinal preparation and sod filters in the mouth, the tobacco or with this kind of mix oxidation inhibitor processing tobacco pipe and the cigarette paper, may eliminate or reduce cigarette haze fr. In this mixture including oxidation inhibitor enzymes and so on l- Guguangantai, catalase and sod, this kind can eliminate including the sod oxidation inhibitor mixture, neutral by the combustion or heating tobacco product releases fr, thus reduces smoking the damage which to the population pharyngeal cavity, the respiratory tract as well as the lungs creates.

Suggestion

　In brief, sod (sickness) the nature and reduces the cigarette haze ofr aspect in the enhancement tobacco resistance to have the good function. However domestic and foreign studies few, therefore, to meet the low harm cigarette need to develop, should strengthen sod in two smoke production aspect foundation and the applied research:①Produces the sound tobacco using sod, namely in leaf tobacco growth period employs sod or has the fine character transgene tobacco using the sod genetic resources and the genetic engineering technology cultivation, Strengthens the smoke seedling, a smoke resistance (sickness) the nature, reduces the agricultural chemicals amount of use;②Produces the low harm cigarette using biological source active sod, if filters the mouth activated charcoal with the suitable densitys sod solution treatment, or joins sod filters in the mouth plasticizer, reduces or the elimination cigarette haze free radical.