【摘要】：綠僵菌(Metarhizium anisopliae)作為一類重要昆蟲病原真菌生防潛力巨大。在自然條件下,綠僵菌主要以孢子控制害蟲。孢子成熟時間的長,生產(chǎn)成本高,易受環(huán)境的影響,殺蟲速度慢等都制約真菌農(nóng)藥的大規(guī)模生產(chǎn)及其應用。在高溫、營養(yǎng)缺陷等不利條件下,自身能進行微循環(huán)產(chǎn)孢。微循環(huán)產(chǎn)孢是絲狀真菌遇到逆境條件的一種自我保護機制,具有產(chǎn)孢速度快,產(chǎn)孢量大,孢子大小更為均一等優(yōu)點,但目前該機制的相關基因研究報道尚少。為了明確微循環(huán)產(chǎn)孢的機制,我們課題組在前期構建了綠僵菌微循環(huán)產(chǎn)孢時期的均一化全長c DNA文庫和微循環(huán)產(chǎn)孢時期的差減文庫,發(fā)現(xiàn)桔霉素生物合成氧化還原酶Ctn B基因在上述文庫中上調(diào)表達。根據(jù)綠僵菌全基因組序列克隆得到桔霉素生物合成氧化還原酶基因Ma Ctn B,并采用基因敲除策略對該基因功能進行研究,主要研究結果如下:①Ma Ctn B影響綠僵菌在微循環(huán)產(chǎn)孢培養(yǎng)基上的的產(chǎn)孢方式和產(chǎn)孢量,以及影響了綠僵菌在正常培養(yǎng)基上的萌發(fā);②桔霉素影響了綠僵菌的產(chǎn)孢方式;③Ma Ctn B影響綠僵菌對紫外輻射和濕熱的敏感性,但不影響細胞壁完整性、抗氧化還原能力以及離子滲透壓的耐受性;④Ma Ctn B影響綠僵菌的毒力:其機制是綠僵菌在寄主體壁穿透階段中的萌發(fā)、附著胞的形成、膨壓有一定影響;但主要在體內(nèi)定殖階段,通過影響綠僵菌在寄主體內(nèi)蟲菌體的生長,寄主血細胞的數(shù)量以及血細胞的吞噬作用來影響寄主的先天免疫,從而降低了毒力。
[Abstract]:Metarhizium anisopliae (Metarhizium anisopliae) has great biocontrol potential as an important class of entomopathogenic fungi. Under natural conditions, Metarhizium anisopliae mainly uses spores to control pests. The long maturation time of spores, high production cost, easy to be affected by environment and slow insecticidal rate all restrict the large-scale production and application of fungal pesticides. Under such unfavorable conditions as high temperature and nutritional deficiency, microcirculation sporulation can be carried out. Microcirculatory sporulation is a self-protective mechanism of filamentous fungi under adverse conditions. It has the advantages of fast sporulation, large sporulation and more uniform spores size. However, there are few studies on the genes related to this mechanism. In order to clarify the mechanism of microcirculation sporulation, our group constructed a homogeneous full-length c DNA library and a differential subtractive library during microcirculatory sporulation stage of Metarhizium anisopliae. It was found that Ctn B gene of citrinin biosynthesis redox enzyme was up-regulated in the above library. According to the whole genome sequence of Metarhizium anisopliae, the Ma Ctn B, gene of citrinin biosynthesis redox enzyme was cloned and the function of the gene was studied by gene knockout strategy. The main results were as follows: 1Ma Ctn B affected the sporulation mode and sporulation quantity of Metarhizium anisopliae on microcirculation sporulation medium and the germination of Metarhizium anisopliae on normal medium. (2) citrinin affected the sporulation of Metarhizium anisopliae, 3Ma Ctn B affected the sensitivity of Metarhizium anisopliae to ultraviolet radiation and damp heat, but it did not affect the integrity of cell wall, the ability of antioxidant reduction and the tolerance of ion osmotic pressure. 4Ma Ctn B affects the virulence of Metarhizium anisopliae: the mechanism is the germination of Metarhizium anisopliae in the stage of wall penetration, the formation of appura, and the influence of swelling pressure. But in the colonization stage, the innate immunity of the host was affected by affecting the growth of Metarhizium anisopliae in the host, the number of the host blood cells and the phagocytosis of the blood cells, thus reducing the virulence of the host.
【學位授予單位】：重慶大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S476.12

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1 馬俊義;李盡哲;葉兆偉;;生物農(nóng)藥的應用現(xiàn)狀及前景展望[J];江蘇農(nóng)業(yè)科學;2011年04期

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本文編號：2423079