本文關(guān)鍵詞：枯草芽孢桿菌QM3對鉛脅迫小麥根系的緩解效應(yīng)　出處：《山西師范大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： QM3菌株 鉛脅迫 小麥根系 生理生化特性 細(xì)胞形態(tài)結(jié)構(gòu)

【摘要】：重金屬鉛嚴(yán)重影響植物生長發(fā)育導(dǎo)致農(nóng)業(yè)作物產(chǎn)量嚴(yán)重下降,這已成為迫切解決的問題,而生物修復(fù)法越來越引起人們的注意。在微生物方面能夠篩選出一株既能夠減輕重金屬鉛污染又能夠促進(jìn)作物生長狀況的菌株具有很重要的意義�？莶菅挎邨U菌(Bacillus subtilis)是一類生防細(xì)菌,既能夠促進(jìn)植物生長又能夠緩解重金屬對植物的脅迫傷害,菌株不同其緩解效應(yīng)也不同。本文以小麥為實驗材料,研究不同濃度的B.subtilis QM3菌液對Pb2+脅迫環(huán)境中小麥根系的理化特性以及根尖細(xì)胞形態(tài)的影響,為研究緩解植物重金屬脅迫以及開發(fā)微生物的農(nóng)業(yè)新應(yīng)用提供理論依據(jù)。下面是本文主要的研究結(jié)果:(1)重金屬鉛對小麥根系具有抑制其生長的作用。鉛脅迫可明顯降低根長、根表面積、根系總體積及根系投影面積,且鉛濃度越高抑制效果越明顯。鉛脅迫環(huán)境下,B.subtilis QM3菌液對小麥根系形態(tài)各個指標(biāo)均有顯著的促進(jìn)作用,當(dāng)Pb2+濃度為500mg/L時,107 CFU/mL B.subtilis QM3菌液可使根長、根表面積、根系體積以及根系投影面積分別提高43.37%、42.28%、237.80%、286.06%(p0.05)。(2)鉛脅迫使小麥根系生物量以及根系活力呈現(xiàn)先增大后減小的趨勢,均在Pb2+為50mg/L時達(dá)到最大值,且鉛濃度越高抑制效果越明顯,B.subtilis QM3菌液處理小麥根系能夠促進(jìn)其生物量的積累、提高根系活力,當(dāng)Pb2+濃度為250 mg/L時,107CFU/mL B.subtilis QM3菌液可使生物量以及根系活力分別提高6.87%、99.93%(p0.05)。(3)鉛脅迫使小麥根系可溶性糖、可溶性蛋白、Pro、MDA以及細(xì)胞膜相對透性(電導(dǎo)率)均增加。低濃度Pb脅迫,不同濃度B.subtilis QM3菌液處理均能明顯降低以上物質(zhì)在根系中的含量以及降低細(xì)胞膜的相對透性,當(dāng)Pb2+濃度為500 mg/L時,107 CFU/mL B.subtilis QM3菌液可使細(xì)胞膜相對透性降低13.82%(p0.05)。(4)Pb脅迫可誘導(dǎo)小麥根系SOD、CAT、APX和POD活性隨著Pb濃度的增大呈現(xiàn)先增大后減小的趨勢。B.subtilis QM3處理能夠有效提高Pb脅迫環(huán)境中根系的抗性酶活性,當(dāng)Pb2+濃度為500 mg/L時,107 CFU/mL B.subtilis QM3菌液可使SOD、CAT、APX和POD分別提高5.38%、83.46%、44.17%、10.11%(p0.05)。(5)鉛脅迫使小麥根系還原型谷胱甘肽(GSH)含量和抗壞血酸(ASA)含量先升高后降低。當(dāng)Pb2+為50、250、2000mg/L時,B.subtilis QM3菌液可顯著提高根系GSH含量(p0.05);中低濃度鉛脅迫,B.subtilis QM3菌液可顯著提高根系A(chǔ)SA含量。(6)鉛脅迫可導(dǎo)致小麥根系表皮細(xì)胞厚度、寬度隨著Pb濃度的增大呈現(xiàn)先增大后減小的趨勢。低鉛脅迫時,菌液處理組較無菌水處理組細(xì)胞形態(tài)更為完整,而在中高鉛濃度下時,無菌水處理組細(xì)胞形態(tài)較菌液處理組更為完整;無菌水處理,皮層厚度隨Pb2+濃度升高呈先增厚后變薄的趨勢,B.subtilis QM3菌液處理時,當(dāng)鉛濃度為0、50、500mg/L根系皮層厚度均小于無菌水處理組;鉛濃度為2000mg/L時,107CFU/ml B.subtilis QM3處理組皮層厚度大于對照,而108、106CFU/mL B.subtilis QM3菌液處理組皮層厚度卻小于無菌水處理。
[Abstract]:Pb seriously affects plant growth in agricultural crop yield declined seriously, which has become an urgent problem, and bioremediation has attracted more and more attention. To select a strain which has very important significance to reduce heavy metal pollution and can promote crop growth status. Microbial strains in Bacillus subtilis (Bacillus subtilis) is a kind of biocontrol bacteria, which can promote the growth of plants and can alleviate the stress of heavy metals to plants, different strains are different. The mitigation effect of using wheat as experimental materials, B.subtilis QM3 bacteria were studied on the physicochemical characteristics in wheat root stress and the influence on the morphology of Pb2+ the root tip cells, and provide a theoretical basis for the application of new agricultural plant heavy metal stress as the research and development of microbial ease. Here is the main research The results: (1) Pb has inhibiting effect on wheat root. Lead stress can significantly reduce the root length, root surface area, root volume and root area, and lead the higher concentration the more obvious inhibition of lead stress. Under the environment of B.subtilis QM3 bacteria on wheat root morphology indexes were significant effect, when the concentration of Pb2+ was 500mg/L, 107 CFU/mL B.subtilis QM3 bacteria can make the root length, root surface area, root volume and root area were increased by 43.37%, 42.28%, 237.80%, 286.06% (P0.05). (2) the lead stress of root biomass and root activity of wheat increased first and then decreased the trend reached the maximum value at Pb2+ is 50mg/L, and the higher the concentration of lead inhibition effect is more obvious, B.subtilis QM3 bacteria liquid treatment can promote the root biomass accumulation, increase root activity, when the concentration of Pb2+ was 250 mg/L, 107 CFU/mL B.subtilis QM3 can make the bacteria biomass and root activity were increased by 6.87%, 99.93% (P0.05). (3) the lead stress of wheat root soluble sugar, soluble protein, Pro, MDA and cell membrane permeability (electrical conductivity) were increased. The low concentration of Pb stress, different concentrations of B.subtilis QM3 bacteria liquid treatments the above material content significantly decreased in roots and decreased the cell membrane permeability, when the concentration of Pb2+ was 500 mg/L, 107 CFU/mL B.subtilis QM3 bacteria liquid. The relative permeability of cell membrane decreased 13.82% (P0.05). (4) Pb induced wheat root system SOD, CAT, APX and POD activity with the increase of Pb concentration showed Pb can effectively improve the resistance enzyme activity in root stress environment can.B.subtilis QM3 trend first increased and then decreased, when the concentration of Pb2+ was 500 mg/L, 107 CFU/mL B.subtilis QM3 bacteria can make SOD, CAT, APX and POD were increased by 5.38%, 83.4 6%, 44.17%, 10.11% (P0.05). (5) the lead stress of wheat root glutathione (GSH) and the content of ascorbic acid (ASA) content increased first and then decreased. When the Pb2+ is 502502000mg/L, B.subtilis QM3 solution can significantly increase the GSH content of root (P0.05); low concentration of lead stress, B.subtilis QM3 broth can significantly increase the ASA content in root. (6) lead stress can lead to root epidermal thickness, width along with the increase of Pb concentration increased first and then decreased. Low lead stress, compared with sterile water treatment group cell morphology is more complete in bacteria, high concentration of lead, sterile water treatment group cells than bacteria group is more complete; aseptic water treatment, cortical thickness increased with the concentration of Pb2+ was thicker after thinning trend, B.subtilis QM3 broth processing, when the lead concentration is 0,50500mg/L root skin thickness were less than the sterile water treatment group When the lead concentration is 2000mg/L, the cortical thickness of 107CFU/ml B.subtilis QM3 treatment group is larger than that of the control group, while the thickness of cortex of 108106CFU/mL B.subtilis QM3 bacteria treatment group is smaller than that of aseptic water treatment.

【學(xué)位授予單位】：山西師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：S512.1;S182

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