矮牵牛PhCESA3基因功能鉴定

发布时间：2018-04-04 09:59

  本文选题：矮牵牛　切入点：PhCESA3　出处：《华南农业大学》2016年硕士论文

【摘要】：矮牵牛(Petunia hybrida)是多年生草花,常作一、二年生栽培。矮牵牛花色丰富,花期长,是极好的花坛花境造景植物,在园林绿化中具有重要地位。矮牵牛还是研究观赏植物生长和发育的模式植物。株型、株高、花型、花期、育性都是观赏植物的重要特性。多年来,观赏植物育种工作者试图通过多种育种途径(包括引种驯化、杂交育种、诱变育种、单倍体育种、多倍体育种、细胞工程育种、基因工程育种)来改变观赏植物的株型、株高、花型、花期、育性等特性,以丰富观赏植物的种类,满足人们的需求。纤维素是细胞壁的主要成分,是地球上产量最大的生物能源。纤维素的生物合成非常复杂,有多个基因协调调控,纤维素主要由纤维素合成酶合成。纤维素合成酶复合体是一个多亚基大复合体,由多个纤维素合成酶催化亚基组成。纤维素合成酶催化亚基(Cellulose synthase catalytic subunits,CESAs)在植物生长发育以及抗性方面具有重要地位。拟南芥AtCESA3突变导致的功能缺失或其反义转基因改变了植株的生长,包括株高、叶和花的大小以及育性,这些都是观赏植物的重要观赏特性,同时表明AtCESA3在植物生长中起着重要作用。然而,除拟南芥以外,CESA3在其他物种中的研究很少。本文研究了拟南芥AtCESA3的同源基因PhCESA3在矮牵牛中的功能。本研究运用生物信息学软件对矮牵牛PhCESA3编码的蛋白进行了结构和序列分析,并用VIGS技术鉴定了矮牵牛PhCESA3的功能。主要结果如下:(1)矮牵牛PhCESA3编码1083个氨基酸,PhCESA3与AtCESA3和SlCESA3的同源性分别为86.5%和94.8%。(2)PhCESA3在矮牵牛的根、茎、叶、花中均有表达,表达量依次为茎根叶花;在花蕾的不同发育阶段,PhCESA3的表达量不同,从现蕾到开花,PhCESA3的表达量呈现先下降后升高再下降的趋势。(3)成功克隆了PhCESA3的长为274 bp的3’UTR片段,构建了VIGS载体pTRV2-PhCESA3;并用VIGS技术侵染矮牵牛植株。(4)PhCESA3沉默植株的叶片纤维素含量降低,与对照相比降低了31.6%。(5)PhCESA3沉默后植株的表型发生变化,具体表现有:植株变矮;节间、花梗、腺毛、花丝和中柱变短;茎、花梗、腺毛、花丝和中柱直径变粗;叶片变小、变厚;花冠幅变小、花瓣变厚和花冠管变短;柱头、子房、果实和种子出现畸形。(6)PhCESA3沉默后茎、花梗、花丝和中柱表皮细胞纵向变短,横向变宽,细胞出现膨胀;茎和花梗皮层增厚,皮层细胞变宽,但皮层细胞的数量并没有增加;花梗皮层细胞的叶绿体中淀粉粒变小、数量减少甚至消失;叶片和花瓣上下表皮细胞变小,内部细胞膨胀;花梗、花瓣和花丝的表皮细胞壁变薄;中柱结构不对称。(7)PhCESA3沉默后花粉粒出现畸形。PhCESA3沉默导致植株的育性下降,结实率也降低。
[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�佺粨鏋滃�備笅:(1)鐭�鐗电墰PhCESA3缂栫爜1083涓�姘ㄥ熀閰�,PhCESA3涓嶢tCESA3鍜孲lCESA3鐨勫悓婧愭，

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