本文選題：矮牽牛　切入點：PhCESA3　出處：《華南農(nóng)業(yè)大學(xué)》2016年碩士論文

【摘要】：矮牽牛(Petunia hybrida)是多年生草花,常作一、二年生栽培。矮牽�；ㄉS富,花期長,是極好的花壇花境造景植物,在園林綠化中具有重要地位。矮牽牛還是研究觀賞植物生長和發(fā)育的模式植物。株型、株高、花型、花期、育性都是觀賞植物的重要特性。多年來,觀賞植物育種工作者試圖通過多種育種途徑(包括引種馴化、雜交育種、誘變育種、單倍體育種、多倍體育種、細胞工程育種、基因工程育種)來改變觀賞植物的株型、株高、花型、花期、育性等特性,以豐富觀賞植物的種類,滿足人們的需求。纖維素是細胞壁的主要成分,是地球上產(chǎn)量最大的生物能源。纖維素的生物合成非常復(fù)雜,有多個基因協(xié)調(diào)調(diào)控,纖維素主要由纖維素合成酶合成。纖維素合成酶復(fù)合體是一個多亞基大復(fù)合體,由多個纖維素合成酶催化亞基組成。纖維素合成酶催化亞基(Cellulose synthase catalytic subunits,CESAs)在植物生長發(fā)育以及抗性方面具有重要地位。擬南芥AtCESA3突變導(dǎo)致的功能缺失或其反義轉(zhuǎn)基因改變了植株的生長,包括株高、葉和花的大小以及育性,這些都是觀賞植物的重要觀賞特性,同時表明AtCESA3在植物生長中起著重要作用。然而,除擬南芥以外,CESA3在其他物種中的研究很少。本文研究了擬南芥AtCESA3的同源基因PhCESA3在矮牽牛中的功能。本研究運用生物信息學(xué)軟件對矮牽牛PhCESA3編碼的蛋白進行了結(jié)構(gòu)和序列分析,并用VIGS技術(shù)鑒定了矮牽牛PhCESA3的功能。主要結(jié)果如下:(1)矮牽牛PhCESA3編碼1083個氨基酸,PhCESA3與AtCESA3和SlCESA3的同源性分別為86.5%和94.8%。(2)PhCESA3在矮牽牛的根、莖、葉、花中均有表達,表達量依次為莖根葉花;在花蕾的不同發(fā)育階段,PhCESA3的表達量不同,從現(xiàn)蕾到開花,PhCESA3的表達量呈現(xiàn)先下降后升高再下降的趨勢。(3)成功克隆了PhCESA3的長為274 bp的3’UTR片段,構(gòu)建了VIGS載體pTRV2-PhCESA3;并用VIGS技術(shù)侵染矮牽牛植株。(4)PhCESA3沉默植株的葉片纖維素含量降低,與對照相比降低了31.6%。(5)PhCESA3沉默后植株的表型發(fā)生變化,具體表現(xiàn)有:植株變矮;節(jié)間、花梗、腺毛、花絲和中柱變短;莖、花梗、腺毛、花絲和中柱直徑變粗;葉片變小、變厚;花冠幅變小、花瓣變厚和花冠管變短;柱頭、子房、果實和種子出現(xiàn)畸形。(6)PhCESA3沉默后莖、花梗、花絲和中柱表皮細胞縱向變短,橫向變寬,細胞出現(xiàn)膨脹;莖和花梗皮層增厚,皮層細胞變寬,但皮層細胞的數(shù)量并沒有增加;花梗皮層細胞的葉綠體中淀粉粒變小、數(shù)量減少甚至消失;葉片和花瓣上下表皮細胞變小,內(nèi)部細胞膨脹;花梗、花瓣和花絲的表皮細胞壁變薄;中柱結(jié)構(gòu)不對稱。(7)PhCESA3沉默后花粉粒出現(xiàn)畸形。PhCESA3沉默導(dǎo)致植株的育性下降,結(jié)實率也降低。
[Abstract]:Petunia hybrida (Petunia hybrida) is a perennial grass often cultivated for one or two years.Petunia is an excellent flower bed plant with rich flower color and long flowering period, and plays an important role in landscaping.Petunia is also a model plant for studying the growth and development of ornamental plants.Plant type, plant height, flower type, flowering period and fertility are important characteristics of ornamental plants.For many years, ornamental plant breeders have tried to use a variety of breeding approaches (including introduction and domestication, hybrid breeding, mutagenesis, haploid breeding, polyploid breeding, cell engineering breeding).Genetic engineering breeding) to change the plant type, plant height, flower type, flowering, fertility and other characteristics, in order to enrich the variety of ornamental plants, to meet the needs of people.Cellulose is the main component of the cell wall and the largest bioenergy source on Earth.The biosynthesis of cellulose is very complicated and regulated by many genes. Cellulose is mainly synthesized by cellulose synthase.Cellulose synthase complex (Cellulose Synthase complex) is a large multisubunit complex composed of several catalytic subunits of cellulose synthase.Cellulose synthase (Cellulose synthase catalytic subunits as) plays an important role in plant growth, development and resistance.Loss of function or antisense transgene caused by Arabidopsis AtCESA3 mutations alter plant growth, including plant height, leaf and flower size, and fertility, which are important ornamental properties of ornamental plants.At the same time, AtCESA3 plays an important role in plant growth.However, there are few studies on CESA3 in other species except Arabidopsis thaliana.The function of homologous gene PhCESA3 of Arabidopsis thaliana AtCESA3 in petunia was studied.In this study, the structure and sequence of the protein encoded by PhCESA3 in Petunia hybrida were analyzed by bioinformatics software, and the function of PhCESA3 was identified by VIGS technique.涓昏緇撴灉濡備笅:(1)鐭壍鐗汸hCESA3緙栫爜1083涓皚鍩洪吀,PhCESA3涓嶢tCESA3鍜孲lCESA3鐨勫悓婧愭，

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