本文選題：銅脅迫　切入點：番茄　出處：《山東農業(yè)大學》2015年碩士論文

【摘要】：一氧化氮(NO)作為生物活性分子,廣泛參與各種生物和非生物脅迫。采用營養(yǎng)液培養(yǎng),研究銅脅迫下外源NO介導的番茄GSH-PCs、多胺代謝途徑中相關酶活性及代謝產物的變化規(guī)律。研究結果表明:1.與CK相比,銅脅迫可以顯著激活番茄體內γ-ECS、GS活性,根系GSH、PCs含量急劇升高,且隨著處理時間的延長,γ-ECS、GS活性和GSH、PCs含量呈持續(xù)上升趨勢;添加外源SNP(NO供體)可以進一步提高銅脅迫下番茄根系γ-ECS、GS活性,促進GSH、PCs的合成,增強清除過氧化物的能力,并螯合過多的Cu2+,降低其生物毒性。葉片中的GSH-PCs代謝變化一定程度上滯后于根系。外源BSO(GSH合成抑制劑)顯著抑制根系γ-ECS活性,添加SNP可以顯著逆轉根系中BSO對GSH和PCs合成的抑制,對葉片中PCs合成的影響較小。銅脅迫下,外源NO可能啟動了某些信號機制,并通過激活或增強GSH-PCs合成途徑中的酶促和非酶促系統(tǒng),降低過多Cu2+的生物毒性和氧化傷害。2.Cu脅迫下添加外源SNP(硝普鈉,外源NO供體)能夠調節(jié)番茄根系和葉片中精氨酸脫羧酶(Arginine Decarboxylase,ADC)、鳥氨酸脫羧酶(Ornithine Decarboxylase,ODC)及一氧化氮合酶(N itric O xide Synthase,NOS)活性。根系中,外源SNP能夠上調NOS活性,L-精氨酸代謝向著NO合成方向進行;葉片中,外源SNP能夠同時上調ADC、ODC、NOS活性,PA、NO的合成同時進行;銅脅迫下添加外源SNP能夠降低番茄幼苗葉片和根系中脯氨酸含量,緩解脅迫;此外,Cu脅迫下添加外源SNP能夠增加根系和葉片L-精氨酸含量,而作為PA、NO的合成前體,精氨酸含量升高無疑會間接促進PA、NO的合成,從而提高番茄對Cu脅迫的抵抗能力。
[Abstract]:Nitric oxide (no), as a bioactive molecule, is widely involved in various biotic and abiotic stresses. The changes of enzyme activity and metabolites in the metabolic pathway of GSH-PCsand polyamine in tomato under copper stress were studied. The results showed that compared with CK, Cu stress could significantly activate 緯 -ECSGS activity in tomato, and increase the content of GSHNs in roots. In addition, the activity of 緯 -ECSGS and the content of GSH- SNP(NO increased with the prolongation of treatment time, and the activity of 緯 -ECSGS in tomato roots was further increased, and the synthesis of GSH- ECSGS and the ability of scavenging peroxides were enhanced by adding exogenous SNP(NO donor. The metabolic changes of GSH-PCs in leaves lagged behind those of roots to some extent. Exogenous BSO(GSH synthesis inhibitors significantly inhibited the activity of 緯 -ECS in roots. The addition of SNP could significantly reverse the inhibition of GSH and PCs synthesis by BSO in roots, but had little effect on PCs synthesis in leaves. Under copper stress, exogenous no might activate some signaling mechanisms. By activating or enhancing the enzymatic and non-enzymatic systems in the GSH-PCs synthesis pathway, the biotoxicity of excessive Cu2 and the oxidative injury of Cu2 were reduced by adding exogenous SNPs (sodium nitroprusside) under stress. Exogenous no donor could regulate the activities of arginine decarboxylase (Arginine decarboxylase), ornithine decarboxylase (Ornithine decarboxylase) and nitric oxide synthase (N itric O xide Synthase) in tomato roots. Exogenous SNP could up-regulate NOS activity and L-arginine metabolism in the direction of no synthesis, and exogenous SNP could also up-regulate the synthesis of NOS activity in leaves. Under copper stress, exogenous SNP could decrease the content of proline in leaves and roots of tomato seedlings and alleviate the stress. In addition, the addition of exogenous SNP could increase the content of L- arginine in roots and leaves of tomato seedlings under Cu stress. The increase of arginine content could indirectly promote the synthesis of PANO and thus enhance the resistance of tomato to Cu stress.
【學位授予單位】：山東農業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：X53;Q945.78

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本文編號：1661393