發(fā)布時間：2018-05-05 10:46

  本文選題：水稻 + 衰老��； 參考：《華中農(nóng)業(yè)大學》2017年博士論文

【摘要】：衰老作為多細胞生物生命周期的最終環(huán)節(jié),一直備受關注。葉片衰老是植物生長發(fā)育的重要階段,伴隨著氮元素等有益離子從衰老的葉片中向幼葉等源組織以及種子等庫組織中轉運并重新利用,對種子萌發(fā)、作物產(chǎn)量和品質均有重要影響。同時,葉片衰老也是植物適應環(huán)境的重要手段。水稻葉片的自然衰老是從授粉開始的,由于水稻種質資源抽穗期上的巨大差異,直接以葉片衰老為靶性狀進行全基因組關聯(lián)分析(GWAS)以克隆控制衰老的基因是十分困難的。茉莉素是被廣泛報道參與葉片衰老調控的重要代謝物,通過茉莉素含量的代謝組學全基因組關聯(lián)分析(mGWAS)或許能輔助克隆控制衰老的關鍵基因。本研究以221份水稻種質資源為材料,測定了葉片中10種茉莉素的含量,發(fā)現(xiàn)了具有生物學活性的幾種茉莉素在秈稻品種葉片中的含量顯著高于粳稻。進一步的mGWAS預測到13個位點可能調控茉莉素含量的自然變異。通過對其中最顯著的兩個位點的分析,我們推測編碼果膠甲基酯酶的OsPME1和編碼果膠甲基轉移酶的OsTSD2兩個基因可能調控茉莉素含量。通過檢測轉基因和突變體中茉莉素含量,我們鑒定了OsPME1和OsTSD2正調控水稻葉片中茉莉素積累的功能。通過在30個水稻品種中檢測表達量,我們發(fā)現(xiàn)秈稻中OsPME1的表達量顯著高于粳稻中,提示OsPME1表達量的變異可能影響茉莉素含量的自然變異。通過進一步田間表型的考察鑒定了OsTSD2突變導致水稻葉片衰老的延遲,OsPME1的轉基因材料也出現(xiàn)了黑暗誘導的葉片衰老異常的表型。此外,外源添加Me-JA能夠回復tsd2突變體葉片衰老延遲的表型,這說明tsd2突變體延遲衰老至少部分原因是茉莉素含量的降低。OsPME1和OsTSD2在生化和代謝途徑上并不與茉莉素合成相關,最直接的功能分別是細胞壁果膠去甲基化和甲基化,甲基化的果膠是植物甲醇的主要來源,因此我們推測OsPME1和OsTSD2通過調控由細胞壁果膠去甲基化產(chǎn)生的甲醇影響茉莉素合成。我們首先通過轉基因的方法驗證了PME家族的另一個基因OsPME11和PME抑制子家族(PMEI)的一個基因OsPMEI-1都能影響茉莉素合成相關基因的表達,這說明影響細胞壁果膠甲基化程度的基因都能影響茉莉素合成途徑。進一步向水培培養(yǎng)的水稻外源添加甲醇發(fā)現(xiàn),茉莉素合成途徑相關基因的表達受到甲醇的強烈影響,隨著甲醇的添加茉莉素含量也顯著提高。綜上所述,我們鑒定了甲醇-茉莉素代謝級聯(lián)在促進水稻葉片衰老中的作用。
[Abstract]:Aging, as the final link of multicellular life cycle, has been paid more and more attention. Leaf senescence is an important stage of plant growth and development. With the transfer and reuse of beneficial ions such as nitrogen from the senescent leaves to the young leaves and so on, the seeds germinate. Crop yield and quality have important effects. At the same time, leaf senescence is also an important means for plants to adapt to the environment. The natural senescence of rice leaves begins with pollination. Because of the great difference in heading date of rice germplasm resources, it is very difficult to clone the genes that control senescence by using leaf senescence as the target trait of the whole genome association analysis (GWAS). Jasmine is an important metabolite involved in the regulation of leaf senescence, and it may be helpful to clone the key genes to control senescence by the whole genome association analysis of the content of jasmine. In this study, 221 rice germplasm resources were used to determine the contents of 10 kinds of jasmine in leaves, and it was found that the contents of several kinds of jasmine with biological activity in the leaves of indica rice varieties were significantly higher than those in japonica rice varieties. Further mGWAS predicted that 13 loci might regulate natural variation of jasmine content. Based on the analysis of the most significant two loci, we speculated that the OsPME1 encoding pectin methyl esterase and the OsTSD2 encoding pectin methyltransferase might regulate the content of jasmine. By detecting the content of jasmonin in transgenic and mutant, we identified the function of OsPME1 and OsTSD2 in regulating the accumulation of jasmonin in rice leaves. By detecting the expression of OsPME1 in 30 rice varieties, we found that the expression of OsPME1 in indica rice was significantly higher than that in japonica rice, suggesting that the variation of OsPME1 expression might affect the natural variation of jasmine content. Through further field phenotypic investigation, the transgenic materials with OsTSD2 mutation causing delayed senescence of rice leaves also showed dark induced abnormal phenotypes of leaf senescence. In addition, exogenous addition of Me-JA could restore the delayed senescence phenotype of tsd2 mutants, which indicated that the delayed senescence of tsd2 mutants was at least partly due to the decrease of jasmine content. OsPME1 and OsTSD2 were not related to the biochemical and metabolic pathways of jasmine synthesis. The most direct function is cell wall pectin demethylation and methylation, and methylated pectin is the main source of plant methanol. Therefore, we speculate that OsPME1 and OsTSD2 affect jasmine synthesis by regulating methanol produced by cell wall pectin demethylation. We first demonstrated by transgenic methods that another gene of the PME family, OsPME11, and a gene of the PME suppressor family, OsPMEI-1, could affect the expression of genes associated with jasmine biosynthesis. These results suggest that the genes that affect the degree of pectin methylation in cell wall can affect the biosynthesis of jasmine. It was found that the expression of genes related to jasmine biosynthesis pathway was strongly affected by methanol, and the content of jasmine increased significantly with the addition of methanol. In conclusion, we identified the role of methanol-Jasmine metabolic cascade in promoting senescence in rice leaves.
【學位授予單位】：華中農(nóng)業(yè)大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：S511

【參考文獻】

相關期刊論文 前3條

1 Jinfeng Qi;Jiancai Li;Xiu Han;Ran Li;Jianqiang Wu;Haixin Yu;Lingfei Hu;Yutao Xiao;Jing Lu;Yonggen Lou;;Jasmonic acid carboxyl methyltransferase regulates development and herbivory-induced defense response in rice[J];Journal of Integrative Plant Biology;2016年06期

2 Sang-Hwa Lee;Yasuhito Sakuraba;Taeyoung Lee;Kyu-Won Kim;Gynheung An;Han Yong Lee;Nam-Chon Paek;;Mutation of Oryza sativa CORONATINE INSENSITIVE 1b(OsCOI1b) delays leaf senescence[J];Journal of Integrative Plant Biology;2015年06期

3 Kaori Fukumoto;Kabir Md Alamgir;Yuko Yamashita;Izumi C.Mori;Hideyuki Matsuura;Ivan Galis;;Response of Rice to Insect Elicitors and the Role of OsJAR1 in Wound and Herbivory-Induced JA-lle Accumulation[J];Journal of Integrative Plant Biology;2013年08期

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本文編號：1847397