發(fā)布時(shí)間：2018-03-05 16:15

  本文選題：褪黑素　切入點(diǎn)：細(xì)胞分裂素　出處：《中國科學(xué)院武漢植物園》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：植物激素之間有廣泛而復(fù)雜的相互作用。細(xì)胞分裂素和生長素共同參與調(diào)控?cái)M南芥主根分生組織的分裂和分化影響主根的生長。在植物中,褪黑素作為抗氧化劑和生長調(diào)節(jié)子被廣泛研究。相關(guān)的研究表明,褪黑素以類似于生長素IAA的方式調(diào)節(jié)植物的根系,然而,一些研究則認(rèn)為褪黑素在根的生長過程中的作用與生長素?zé)o關(guān)。最近的一項(xiàng)研究表明,外源高濃度的褪黑素通過抑制生長素合成和極性運(yùn)輸抑制根分生組織,但是到目前為止,關(guān)于低濃度褪黑素在主根生長過程中作用機(jī)理的研究還未見報(bào)道。在本研究中,我們分別以野生型擬南芥(Col-0)和細(xì)胞分裂素合成酶誘導(dǎo)超表達(dá)轉(zhuǎn)基因植株(IPT8-OX)為材料,外源添加褪黑素和細(xì)胞分裂素、誘導(dǎo)劑雌二醇(estradiol)和生長素極性運(yùn)輸抑制劑TIBA后,通過表型分析、相關(guān)基因表達(dá)量、蛋白定量等多方面的研究,探討褪黑素和細(xì)胞分裂素對主根生長的調(diào)控機(jī)理。主要研究結(jié)果如下:(1)低濃度的褪黑素(100 nM)對主根生長起正調(diào)控效應(yīng),通過促進(jìn)根尖分生區(qū)細(xì)胞數(shù)目的增多而促進(jìn)擬南芥主根生長,拮抗外源添加及內(nèi)源誘導(dǎo)細(xì)胞分裂素對主根生長的抑制作用;(2)褪黑素通過抑制細(xì)胞分裂素信號途徑關(guān)鍵基因(AHK4、AHP2、AHP3、AHP5、ARR15)的表達(dá)以拮抗細(xì)胞分裂素對主根生長的調(diào)控作用;(3)褪黑素通過調(diào)控生長素極性運(yùn)輸載體(PIN1、PIN2、PIN3 AUX1、AXR3)的轉(zhuǎn)錄水平使生長素的運(yùn)輸發(fā)生改變。除此之外,褪黑素和細(xì)胞分裂素在蛋白水平上可影響PIN2和AUX1的積累。(4)添加生長素極性運(yùn)輸抑制劑TIBA的實(shí)驗(yàn),說明褪黑素和細(xì)胞分裂素調(diào)控主根生長離不開生長素的轉(zhuǎn)運(yùn)。綜上所述,我們的數(shù)據(jù)表明低濃度褪黑素促進(jìn)擬南芥主根生長,褪黑素和細(xì)胞分裂素在主根生長的調(diào)控過程中具有拮抗作用,而生長素的極性運(yùn)輸在這個(gè)過程中具有重要的作用。相關(guān)研究為進(jìn)一步揭示褪黑素的生物學(xué)功能和激素之間的相互調(diào)控提供了直接的證據(jù),對于以后植物主根的研究也具有重要意義。
[Abstract]:Plant hormones have extensive and complex interactions. Cytokinins and auxins are involved in regulating the division and differentiation of the main root meristem of Arabidopsis thaliana. Melatonin is widely studied as an antioxidant and a growth regulator. Studies have shown that melatonin regulates the roots of plants in a manner similar to that of auxin IAA, however, Some studies suggest that the role of melatonin in root growth is unrelated to auxin. A recent study showed that exogenous high concentrations of melatonin inhibit root meristem by inhibiting auxin synthesis and polar transport, but so far, In this study, we used wild type Arabidopsis thaliana Col-0) and cytokinin synthase induced overexpression transgenic plant IPT8-OX as materials. After exogenous addition of melatonin, cytokinin, estradiol (estradiol) and growth hormone polar transport inhibitor (TIBA), phenotypic analysis, gene expression and protein quantification were studied. To study the mechanism of melatonin and cytokinin regulating the growth of main root. The main results are as follows: 1) the low concentration of melatonin 100 nm) has positive effect on the growth of main root. To promote the growth of Arabidopsis by increasing the number of cells in the apical meristem. Antagonistic effects of exogenous and Endogenous cytokinins on the growth of main Roots; melatonin antagonizes the expression of AHK4 (AHP2AHP3AHP5AHP5ARR15) by inhibiting cytokinin signaling pathway in order to antagonize the regulation of cytokinin on the growth of the main root. Melatonin changes the transport of auxin by regulating the transcription level of the polar transport vector PIN1PIN2PIN3AUX1AXR3. Melatonin and cytokinin can affect the accumulation of PIN2 and AUX1 at protein level. 4) the experiment of adding auxin polar transport inhibitor TIBA shows that melatonin and cytokinin can not regulate the growth of main root without auxin transport. Our data show that low concentration of melatonin promotes the growth of Arabidopsis thaliana main root, and melatonin and cytokinin play an antagonistic role in regulating the growth of Arabidopsis thaliana. The polar transport of auxin plays an important role in this process. Related studies provide direct evidence to further reveal the biological functions of melatonin and the regulation of hormones. It is also of great significance for the study of the main roots of plants in the future.
【學(xué)位授予單位】：中國科學(xué)院武漢植物園
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：Q945

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本文編號：1570976