發(fā)布時間：2018-05-20 16:22

  本文選題：香雪蘭 + 萜類化合物��； 參考：《東北師范大學(xué)》2017年碩士論文

【摘要】：植物揮發(fā)性成分組成復(fù)雜,主要由萜類化合物及其衍生物構(gòu)成。萜類物質(zhì)的合成和釋放對植物在進化過程中適應(yīng)復(fù)雜多變的環(huán)境具有重要的意義。在揮發(fā)性萜類物質(zhì)的生物合成過程中,萜類合酶(terpene snythases,TPS)起到至關(guān)重要的作用。它們可以催化香葉基二磷酸(geranyl diphoshate,GPP)、法尼基二磷酸(farnesyl diphoshate,FPP)、香葉基香葉基二磷酸(geranylgeranyl diphoshate,GGPP)等底物,生成種類豐富的萜類化合物。目前,對于植物TPS基因家族及萜類物質(zhì)代謝的研究主要集中在雙子葉模式植物以及部分重要的農(nóng)作物上,而對揭示進化過程中TPS基因功能多樣性有重要作用的單子葉植物卻研究較少。香雪蘭(Freesia hybrida)屬鳶尾科香雪蘭屬,是重要的單子葉園藝花卉。其花香濃郁,馥郁芬芳,花期較長,是研究植物揮發(fā)性萜類物質(zhì)代謝的優(yōu)良材料。本研究基于香雪蘭常見栽培種(Red River?)轉(zhuǎn)錄組數(shù)據(jù),利用RACE-PCR技術(shù)成功從中克隆得到一個萜類合酶基因FhTPS4,cDNA全長為1701 bp,編碼566個氨基酸。生物信息學(xué)分析表明,其氨基酸序列具有萜類合酶家族典型的DDXXD和NSE/DET保守結(jié)構(gòu)域。進化樹分析發(fā)現(xiàn),FhTPS4聚類于TPS-g亞家族。TPS-g亞家族的TPS多具有雙功能的萜類合酶催化性質(zhì),既能催化GPP合成單萜物質(zhì),又能催化FPP合成倍半萜物質(zhì)。研究表明,TPS-g亞家族的TPS多數(shù)定位于葉綠體,本研究通過原生質(zhì)體瞬時轉(zhuǎn)染技術(shù)證明FhTPS4也定位于葉綠體中,暗示其參與了控制單萜物質(zhì)合成的質(zhì)體代謝途徑(MEP pathway)。此外,體外酶活實驗結(jié)果顯示FhTPS4可催化GPP和FPP底物分別生成沉香醇和橙花叔醇,即FhTPS4同時具有單萜合酶和倍半萜合酶兩種功能。為了進一步探究FhTPS4在香雪蘭植物體內(nèi)的功能,通過Real-time PCR分析FhTPS4基因時空表達模式,結(jié)合前期對香雪蘭花朵揮發(fā)性成分分析證明,香雪蘭體內(nèi)FhTPS4的功能是催化花托和花萼中沉香醇的合成。
[Abstract]:The volatile components of plants are complex, mainly composed of terpenoids and their derivatives. The synthesis and release of terpenoids play an important role in the evolution of plants. Terpene synthase (TPS) plays an important role in the biosynthesis of volatile terpenes. They can catalyze the substrates of geranyl diphoshatetate, farnesyl diphoshatefen, geranylgeranyl diphoshatetate (GGPP) and other substrates to form terpenoids of rich species. At present, the studies of plant TPS gene family and terpene metabolism are mainly focused on dicotyledonous model plants and some important crops. However, there are few studies on monocotyledonous plants that play an important role in revealing the functional diversity of TPS gene during evolution. Freesia hybrida is an important monocotyledonous horticultural flower. It is an excellent material for studying the metabolism of volatile terpenes in plants. This study is based on Red Rivera, a common cultivated species of Xanthoxylum sinensis. Transcriptome data were used to clone a terpene synthase gene FhTPS4 cDNA with a length of 1701 BP encoding 566 amino acids. Bioinformatics analysis showed that its amino acid sequence had the conserved domains of DDXXD and NSE/DET of terpene synthase family. Phylogenetic tree analysis showed that the TPS clustered in the TPS-g subfamily. TPS-g subfamily had bifunctional terpene synthase catalytic properties, which could catalyze the synthesis of monoterpenes from GPP and the synthesis of sesquiterpenes by FPP. The results showed that most of TPS of TPS-g subfamily was located in chloroplast. In this study, we demonstrated that FhTPS4 was located in chloroplast by protoplast transient transfection technique, suggesting that FhTPS4 was involved in the plastid metabolic pathway that controlled the synthesis of monoterpenes. In addition, the results of enzyme activity in vitro showed that FhTPS4 could catalyze GPP and FPP substrates to produce amethanol and nerolol, that is, FhTPS4 had two functions: monoterpene synthase and sesquiterpene synthase. In order to further explore the function of FhTPS4 in the plant, the expression pattern of FhTPS4 gene in time and space was analyzed by Real-time PCR. The function of FhTPS4 is to catalyze the synthesis of amarol in receptacle and calyx.
【學(xué)位授予單位】：東北師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：Q943.2

【參考文獻】

相關(guān)期刊論文 前6條

1 呂麗敏;張帥;雒s，

本文編號：1915384