番茄(Solanum lycopersicum)果胶酸裂解酶P56在大肠杆菌中的重组表达

果胶酸裂解酶P56在番茄花粉管伸长过程中起着重要的作用,为了制备番茄P56蛋白的抗体,进行番茄花粉管萌发过程中P56蛋白的免疫组织化学研究,对P56基因在大肠杆菌系统的重组表达进行了研究。先采用Overlap-PCR的方法,从番茄基因组DNA中克隆了成熟P56蛋白的cDNA序列(LAT56),再构建重组表达质粒pET28a( )-LAT56,转化大肠杆菌BL21-CodenPlus(DE3)-RIL,得到了重组表达工程菌pET-28a( )-LAT56-BL21-Co-denPlus(DE3)-RIL。在0.5 mmol/L IPTG、15℃和180 r/min条件下,经过60 h的诱导培养,重组蛋白表达量为细胞总蛋白的30%左右,主要以包涵体形式存在,重组蛋白经Ni2 -nitrilotriacetate-agrose亲和柱层析,得到了SDS-PAGE显示为单一蛋白带的纯化蛋白。     

番茄(Solanum lycopersicum)果胶酸裂解酶P56在大肠杆菌中的重组表达

果胶酸裂解酶P56在番茄花粉管伸长过程中起着重要的作用,为了制备番茄P56蛋白的抗体,进行番茄花粉管萌发过程中P56蛋白的免疫组织化学研究,对P56基因在大肠杆菌系统的重组表达进行了研究。先采用Overlap-PCR的方法,从番茄基因组DNA中克隆了成熟P56蛋白的cDNA序列(LAT56),再构建重组表达质粒pET28a(+)-LAT56,转化大肠杆菌BL21-CodenPlus(DE3)-RIL,得到了重组表达工程菌pET-28a(+)-LAT56-BL21-Co-denPlus(DE3)-RIL。在0.5 mmol/L IPTG、15℃和180 r/min条件下,经过60 h的诱导培养,重组蛋白表达量为细胞总蛋白的30%左右,主要以包涵体形式存在,重组蛋白经Ni²⁺-nitrilotriacetate-agrose亲和柱层析,得到了SDS-PAGE显示为单一蛋白带的纯化蛋白。     

Biocontrol of broomrape using Fusarium oxysporum f. sp. orthoceras in tomato crops under field conditions

The effects of Fusarium oxysporum f. sp. orthoceras as a mycoherbicide on broomrape, a weedy parasite of tomato crops, were examined during two growing seasons under field conditions. In contrast to emerged broomrapes in treated plots, none of the tomato plants inoculated with fungal pathogen showed Fusarium-wilt symptoms. In 2008, both suspension concentrations, 1?×?10⁶ and 1?×?10⁷ spore/ml, used via either root-dip or soil-inoculation three weeks after transplanting, and high-concentration-soil-inoculation one week after transplanting, reduced the number of broomrape plant and shoots per plant compared to the control. In 2009, single-point-low-dose and twice-high-dose applications of sulfosulfuron had significantly fewer broomrape plants than high-concentration-soil-inoculation three weeks after transplanting. High-concentration-root-dip inoculation decreased broomrape biomass weight significantly by 58% compared to the control in 2008. In 2009, mean biomass for single-point-application of sulfosulfuron at 50 and 75?g levels was lower than control. The highest yield was detected in high-concentration-soil-inoculation at transplanting in 2008 and in low-dose-twice-application of sulfosulfuron in 2009. Tomato yield was associated with the number of broomrape shoots per plant. There is promise that these field-scale findings will improve attempts to use mycoherbicides for biocontrol of broomrapes in tomato cropping systems.     

毛酸浆(Physalis pubescens)花形态特征与小孢子发育

许多重要蔬菜和水果隶属于茄科(Solanaceae),植物花发育是物种延续和产品形成关键决定因子。茄科毛酸浆(Physalispubescens)是药食同源半野生浆果,目前其花发育研究不多。为了从不同视角了解茄科植物花发育,本研究采用比较生物学方法从花的形态特征和解剖学层面解析了毛酸浆(P.pubescens)和茄科模式植物番茄(Solanum lycopersicum var. cerasiforme)花器特征和小孢子发育进程。结果显示,开花后毛酸浆花萼迅速生长包被果实、花瓣有紫色斑纹、花药顶颈可育及背部开裂散粉特征与番茄花萼生长缓慢、黄色花瓣、花药顶颈不育及腹缝开裂散粉方式截然不同,展示了茄科植物遗传多样性。毛酸浆小孢子发育,在“四分体”之前迟于番茄,而“四分体”之后期却快于番茄。特别是番茄药隔组织在“四分体”时期开始向药室异常内突,并在花粉成熟期占据药室近1/2空间,而未在毛酸浆中观察到。该研究为开发茄科新的模式植物和从不同视角理解庞大茄科植物花发育提供了重要信息。     

A snapshot of the Chinese SOL Project

In 2003, the International Solanaceae Project (SOL) was initiated by an international consortium of ten countries including Korea, China, the United Kingdom, India, the Netherlands, France, Japan, Spain, Italy and the United States. The first major effort of the SOL aimed to produce a DNA sequence map for euchromatin regions of 12 chromosomes of tomato (Solanum lycopersicum) before 2010. Here we present an update on Chinese effort for sequencing the euchromatin region of chromosome 3.     

Domestication and Breeding of Tomatoes: What have We Gained and What Can We Gain in the Future?

Background

It has been shown that a large variation is present and exploitable from wild Solanum species but most of it is still untapped. Considering the thousands of Solanum accessions in different gene banks and probably even more that are still untouched in the Andes, it is a challenge to exploit the diversity of tomato. What have we gained from tomato domestication and breeding and what can we gain in the future?

Scope

This review summarizes progress on tomato domestication and breeding and current efforts in tomato genome research. Also, it points out potential challenges in exploiting tomato biodiversity and depicts future perspectives in tomato breeding with the emerging knowledge from tomato-omics.

Conclusions

From first domestication to modern breeding, the tomato has been continually subjected to human selection for a wide array of applications in both science and commerce. Current efforts in tomato breeding are focused on discovering and exploiting genes for the most important traits in tomato germplasm. In the future, breeders will design cultivars by a process named ‘breeding by design’ based on the combination of science and technologies from the genomic era as well as their practical skills.Key words: Breeding, domestication, genomics, Solanum lycopersicum     

The Role of Viral Infection in Inducing Variability in Virus-Free Progeny in Tomato

The effect of virus-host interactions on subsequent generations is poorly understood. The evaluation of the effects of viral infection on inheritance of quantitative traits in the progeny of infected plants and elucidation of a possible relationship between chiasma frequency in the infected plants and variability of traits in the progeny were investigated. The current study involved genotypes of four intraspecific hybrids of tomato （Solanum lycopersicum L.）, their parental forms and two additional cultivars. Used as infection were the tobacco mosaic virus （TMV） and potato virus X （PVX）. The consequences of the effect of viral infection were evaluated based on chromosome pairing in diakinesis and/or by examining quantitative and qualitative traits in the progeny of the infected tomato plants. Tomato plants infected with TMV ＋ PVX were found to differ in chiasma frequency per pollen mother cell or per bivalent. Deviations have been observed for genotypes of both F1 hybrids and cultivars. At the same time, differences in mean values of the traits under study have only been found for progeny populations （F2-F4） derived from virus-infected F1 hybrids, but not in the case of progeny of the infected cultivars. The rate of recombinants combining traits of both parents increased significantly （2.22-8.24 times） in progeny populations of hybrids infected with TMV＋PVX. The above suggests that the observed effects could be the result of modification of recombination frequencies that can be manifested in heterozygous hybrids and make small contributions to variability in cases of ＇homozygous＇ tomato genotypes （i.e. cultivars）.     

番茄WOX转录因子家族的鉴定及其进化、表达分析

WUSCHEL相关的同源异型盒(WUSCHEL-related homeobox,WOX)是一类植物特异的转录因子家族,具有调控植物干细胞分裂分化动态平衡等重要功能。本研究利用番茄(Solanum lycopersicum)基因组数据,通过建立隐马尔科夫模型并进行检索,鉴定了番茄10个WOX转录因子家族成员。多序列比对发现,番茄WOX转录因子家族成员具有高度保守的同源异型结构域;以拟南芥WOX转录因子家族成员序列为参照,通过邻接法、极大似然法、贝叶斯法重建了系统发育树,三者呈现出类似的拓扑结构,番茄和拟南芥WOX转录因子家族共25个成员被分为3个进化支(Clade)和9个亚家族(Subgroup);利用MEME和GSDS对WOX转录因子家族成员的蛋白保守结构域和基因结构进行了分析,同一亚家族内的WOX转录因子家族成员的保守结构域的种类、组织形式以及基因结构具有高度的一致性;利用Perl和Orthomcl对家族成员的染色体定位和同源性关系进行分析,结果表明串联重复的SlWOX3a和SlWOX3b可能来源于一次复制事件;利用番茄转录组数据和qRT-PCR进行表达分析,结果显示家族成员在不同组织中的表达存在差异,暗示了WOX家族的不同成员在功能上可能具有多样性。本研究对番茄WOX转录因子家族成员进行GO(Gene Ontology)注释和比较分析,结果表明该家族成员作为转录因子,可能在组织器官发育、细胞间通讯等过程中发挥作用。     

番茄转录因子SlERF.F4在番茄果实抵御灰霉病中的功能分析

番茄（Solanum lycopersicum L.）是世界上种植最广泛的经济作物之一,具有极大的经济价值,但其极易受到灰葡萄孢（Botrytis cinerea）的影响,造成严重的经济损失。ERF转录因子在植物胁迫响应中发挥关键作用。本研究通过获得番茄SlERF.F4过表达材料,比较其与野生型果实的差异,研究其介导的番茄果实抗灰霉病的功能。结果显示,与野生型番茄品种‘AC’（‘Ailsa Craig’）果实相比,SlERF.F4过表达（SlERF.F4-OE）番茄果实对灰葡萄孢的抗性较强,表现在灰葡萄孢接种后果实病斑扩展速率较慢。生理生化分析结果表明,SlERF.F4-OE果实体内的活性氧（O₂^−.产生速率、H₂O₂含量）和MDA含量低于‘AC’果实,同时,抗氧化酶活性（POD、CAT和SOD酶）高于‘AC’果实。此外,SlERF.F4-OE番茄果实体内苯丙氨酸解氨酶（PAL）活性高于‘AC’果实。研究结果说明,SlERF.F4可通过调节番茄果实活性氧稳态及防御酶活性增强果实对灰葡萄孢的抵抗能力。