番茄生物学研究的相关网络资源

番茄(Solanum lycopersicum)是一种重要的蔬菜作物, 也是研究茄科作物的模式植物。互联网上有丰富的与番茄相关的生物信息学资源, 对其生物学研究带来极大便利。该文介绍了目前网络上与番茄生物学研究相关的资源, 利用这些资源将会加快对番茄遗传学和基因组学及对茄科植物多样性的研究。     

番茄果实早期发育的分子生理机制研究进展

番茄(Solanum lycopersicum)是目前世界上种植面积最广且最受欢迎的蔬菜作物之一, 也是肉果及茄科的重要模式植物。番茄果实发育主要分为早期果实发育和果实成熟2个时期, 但果实形态结构和大小主要决定于早期果实发育时期。该文围绕番茄早期果实发育时期植物激素、细胞周期、表观遗传和源库代谢等多方面调控的分子机制进行了综述, 旨在认识植物生长与发育的基本生物学问题及促进基础理论研究成果在生产中应用。     

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。     

茄科植物线粒体基因组学研究进展

茄科植物作为第一大类蔬菜作物,其经济价值排在植物界第3位,在农业和科学研究等方面具有举足轻重的地位。目前已完成线粒体基因组测序的茄科植物有辣椒、烟草、番茄及天仙子,但有关茄科植物线粒体基因组学的研究较少。本综述从线粒体基因组测序现状、线粒体基因组的结构特点、线粒体基因组分析等3个方面介绍了茄科植物线粒体基因组学研究进展;以线粒体基因组学为基础,重点综述了茄科植物中广泛存在的细胞质雄性不育现象及其机理,为深入研究茄科植物细胞质雄性不育现象提供理论依据;并进一步总结了茄科植物线粒体基因组学对其他植物基因组学研究的参考价值。     

番茄中两个高度同源的NAC类转录因子通过不同的机制调控病原菌诱导的气孔关闭和重新开张

作物-昆虫-病原微生物三者之间存在着复杂的共生、寄生和互惠关系。以不同的互作模型为研究对象,诠释这些互作关系中的种间信息流识别、传递及应答的分子机制,对于提高农作物的抗病虫能力具有科学指导意义。已有研究表明,植物激素茉莉酸(JA)在植物-昆虫-病原微生物的复杂互作系统中起核心调控作用。中国科学院遗传与发育生物学研究所李传友研究组长期致力于研究茉莉酸调控植物先天免疫的分子机理。本研究组作为“国际茄科基因组计划”的重要成员,历经8年多的艰苦努力,和国际同行一道完成了对番茄基因组的精细序列分析(The Tomato Genome Consortium, 2012),为以番茄为模式系统解析植物先天免疫的分子机理奠定了坚实的基础。     

番茄TNAC基因的鉴定及表达分析

TNAC是一组茄科植物特有的NAC基因,目前尚未见有关番茄TNAC基因的报道。前期研究中,我们将来自于番茄、拟南芥和水稻三个物种的NAC蛋白构建进化树,发现有一分支仅包含番茄的26个SlNAC蛋白,本研究对其进一步鉴定和分析。结果显示,其中10个SlNAC蛋白具备TNAC典型序列特征。进而,采用实时定量PCR分析番茄TNAC基因在不同组织器官中的表达情况及对不同胁迫处理的响应模式。除一个番茄TNAC基因的转录产物未被检测到之外,2个在所有器官中均表达,7个均显示出明显的器官特异性。分别用250 mmol·L^-1 NaCl、15% PEG 6000和4℃处理番茄幼苗后,8个TNAC基因对至少一种胁迫有明显的响应。研究结果为预测这些SlNACs的生物学功能提供重要线索,也为深入理解这类茄科植物特有的NAC基因扮演的角色提供新的资料。     

番茄幼叶离体培养的细胞组织学研究

番茄是茄科中最重要的作物。关于番茄的组织培养已有不少工作,但在细胞学方面的研究尚不多。本文报道了在番茄幼叶离体培养过程中,愈伤组织的形成和组织的分化,试图从形态学,细胞组织学等方面     

当前植物环境生物学研究的若干重要问题

本文从植物生物学的角度来讨论植物与环境的关系,概述植物对环境的反应和适应;受控条件下的植物生物学和作物生产;空间生命科学的研究等一些当前受人关注的问题。     

烟粉虱MEAM1和AsiaⅡ7隐种对不同寄主的选择性和生态适应性

广东省感染木尔坦棉花曲叶病毒(CLCuMuV)的朱槿上烟粉虱隐种为MEAM1和AsiaⅡ7混合种群,并且AsiaⅡ7是该病毒有效传毒介体,明确这两个隐种的寄主选择性差异,能够为介体烟粉虱的防治提供依据。本研究选择锦葵科的棉花、黄秋葵和茄科的茄子、番茄4种寄主植物为供试寄主,通过笼内自由扩散、实验室嗅觉测定、发育观察,比较了MEAM1和AsiaⅡ7隐种对不同寄主的选择性和生态适应性。结果表明:烟粉虱MEAM1和AsiaⅡ7对4种寄主存在明显的寄主选择性,MEAM1成虫和产卵选择趋性为棉花>茄子>番茄>黄秋葵;AsiaⅡ7成虫和产卵选择趋性为棉花>黄秋葵>茄子>番茄。MEAM1和AsiaⅡ7在4种寄主上的发育历期、存活率有显著差异,MEAM1的存活率(卵到成虫)在棉花、茄子、黄秋葵上均较高(80%以上),番茄上最低(59%);AsiaⅡ7的存活率(卵到成虫)为棉花(90%)>黄秋葵(71%)>茄子(64%),在番茄上发育至1龄全部死亡。上述结果表明,4种作物均适宜MEAM1生长发育,锦葵科的2种作物适宜AsiaⅡ7隐种生长发育,茄科的2种作物不适宜。应避免棉花与黄秋葵近距离种植,防止传毒介体烟粉虱将黄秋葵作为桥梁寄主将病毒传播至棉花。     

野生蜜蜂及其传粉作用的研究现状

传粉是维持与提升生物多样性的重要生态过程。膜翅目蜜蜂总科昆虫是自然界中最重要的传粉者, 但对野生蜜蜂的研究一直以来非常薄弱, 如野生蜜蜂类群的资源调查、种类的准确鉴别、营巢生物学与传粉生物学研究等方面。目前, 生物多样性与保护生物学方面的工作越来越多地涉及野生蜜蜂与植物的相互关系, 地方植物区系与农林作物的传粉生物学基础研究与应用项目也引起重视。本文综述了国内外野生蜜蜂的研究现状, 期望从分类学、营巢生物学与传粉生物学等方面推动野生蜜蜂传粉在农林业生产实践中的应用。     

ToCV单独侵染和TYLCV&ToCV复合侵染番茄植株上烟粉虱寄主适应性及寄主植物营养成分含量和防御反应变化

[目的]本研究以番茄褪绿病毒(tomato chlorosis virus,ToCV)和番茄黄化曲叶病毒(tomato yellow leaf curl virus,TYLCV)为主体,旨在明确ToCV单独侵染及TYLCV&ToCV复合侵染对烟粉虱Bemisia tabaci MED隐种寄主适应性的影响,并从寄主植物营...     

西红柿的光生态研究

采用叶片的反射光谱测量来研究西红柿的光生态。西红柿叶片在４５０ｎｍ处、６８０ｎｍ处各有一条带宽为１２０ｎｍ的吸收带,这说明蓝、红光能够促进西红柿的生长。往聚乙烯树脂中添加荧光助剂、着色剂模拟西红柿作用光谱制成农膜。用这种农膜苫盖温室大棚进行西红柿生产。通过产量调查来进一步认证西红柿的光生态。     

An avrPto/avrPtoB mutant of Pseudomonas syringae pv. tomato DC3000 does not elicit Pto-mediated resistance and is less virulent on tomato

AvrPto and AvrPtoB are type III effector proteins expressed by Pseudomonas syringae pv. tomato strain DC3000, a pathogen of both tomato and Arabidopsis spp. Each effector physically interacts with the tomato Pto kinase and elicits a hypersensitive response when expressed in tomato leaves containing Pto. An avrPto deletion mutant of DC3000 previously was shown to retain avirulence activity on Pto-expressing tomato plants. We developed an avrPtoB deletion mutant of DC3000 and found that it also retains Pto-specific avirulence on tomato. These observations suggested that avrPto and avrPtoB both contribute to avirulence. To test this hypothesis, we developed an deltaavrPtodeltaavrPtoB double mutant in DC3000. This double mutant was able to cause disease on a Pto-expressing tomato line. Thus, avrPto and avrPtoB are the only avirulence genes in DC3000 that elicit Pto-mediated defense responses in tomato. When inoculated onto susceptible tomato leaves and compared with wild-type DC3000, the mutants DC3000deltaavrPto and DC3000deltaavrPtoB each caused slightly less severe disease symptoms, although their growth rate was unaffected. However, DC3000deltaavr PtodeltaavrPtoB caused even less severe disease symptoms than the single mutants and grew more slowly than them on susceptible leaves. Our results indicate that AvrPto and AvrPtoB have phenotypically redundant avirulence activity on Pto-expressing tomato and additive virulence activities on susceptible tomato plants.     

Molecular cloning of a tomato leaf cDNA encoding an aspartic protease, a systemic wound response protein

A full-length cDNA encoding an aspartic protease (LeAspP) has been cloned from a tomato leaf cDNA library. Using LeAspP cDNA as a probe in gel blots, LeAspP mRNA was shown to be systemically induced in tomato leaves by wounding. Application of methyl jasmonate to leaves of intact tomato plants, or supplying systemin to young tomato plants through their cut stems, induces synthesis of LeAspP mRNA. LeAspP message is regulated in tomato similar to several systemic wound response proteins (swrps) that are part of the defense response in tomato plants directed against herbivore attacks.     

The cloned avirulence gene avrPto induces disease resistance in tomato cultivars containing the Pto resistance gene.

Resistance of tomato plants to the bacterial pathogen Pseudomonas syringae pv. tomato race 0 is controlled by the locus Pto. A bacterial avirulence gene was cloned by constructing a cosmid library from an avirulent P. syringae pv. tomato race, conjugating the recombinants into a strain of P. syringae pv. maculicola virulent on a tomato cultivar containing Pto, and screening for those clones that converted the normally virulent phenotype to avirulence. The cloned gene, designated avrPto, reduced multiplication of P. syringae pv. tomato transconjugants specifically on Pto tomato lines, as demonstrated by bacterial growth curve analyses. Analysis of F2 populations revealed cosegregation of resistance to P. syringae pv. tomato transconjugants carrying avrPto with resistance to P. syringae pv. tomato race 0. Surprisingly, mutation of avrPto in P. syringae pv. tomato race 0 does not eliminate the avirulent phenotype of race 0, suggesting that additional, as yet uncharacterized, avirulence genes and/or resistance genes may contribute to specificity in the avrPto-Pto interaction. Genetic analysis indicates that this resistance gene(s) would be tightly linked to Pto. Interestingly, P. syringae pv. glycinea transconjugants carrying avrPto elicit a typical hypersensitive resistant response in the soybean cultivar Centennial, suggesting conservation of Pto function between two crop plants, tomato and soybean.     

Tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition.

We have employed a genetic approach to study the resistance of tomato to the phytopathogenic bacterium Pseudomonas syringae pv tomato. Resistance to P. s. tomato depends upon expression of the Pto locus in tomato, which encodes a protein with similarity to serine/threonine protein kinases and recognizes pathogen strains expressing the avirulence gene avrPto. Eleven tomato mutants were isolated with altered resistance to P. s. tomato strains expressing avrPto. We identified mutations both in the Pto resistance locus and in a new locus designated Prf (for Pseudomonas resistance and fenthion sensitivity). The genetic approach allowed us to dissect the roles of these loci in signal transduction in response to pathogen attack. Lines carrying mutations in the Pto locus vary 200-fold in the degree to which they are susceptible to P. s. tomato strains expressing avrPto. The pto mutants retain sensitivity to the organophosphate insecticide fenthion; this trait segregates with Pto in genetic crosses. This result suggested that contrary to previous hypotheses, the Pto locus controls pathogen recognition but not fenthion sensitivity. Interestingly, mutations in the prf locus result in both complete susceptibility to P. s. tomato and insensitivity to fenthion, suggesting that Prf plays a role in tomato signaling in response to both pathogen elicitors and fenthion. Because pto and prf mutations do not alter recognition of Xanthomonas campestris strains expressing avrBsP, an avirulence gene recognized by all tested tomato cultivars, Prf does not play a general role in disease resistance but possibly functions specifically in resistance against P. s. tomato. Genetic analysis of F2 populations from crosses of pto and prf homozygotes indicated that the Pto and Prf loci are tightly linked.     

Anti-allergic activity of naringenin chalcone from a tomato skin extract

The anti-allergic activity of a tomato extract was studied by using an in vitro histamine-release assay. The tomato skin extract exerted the strongest inhibition of histamine release. Chlorogenic acid, rutin and naringenin were identified in the 60% ethanol extract of tomato skin. However, the extract contained an unknown compound which strongly inhibited histamine release. This active compound in tomato skin was identified as naringenin chalcone (trans-2'4'6'4-tetrahydroxychalcone). Naringenin chalcone inhibited histamine release with an IC(50) value of 68 microg/ml. The anti-allergic activity of the tomato skin extract was next investigated by the in vivo mouse ear-swelling response. We found that naringenin chalcone showed the strongest inhibitory effect of the polyphenols of the tomato skin extract. These results indicate that a tomato skin extract could inhibit allergic reactions.     

Plant cues influence searching behaviour and parasitism in the egg parasitoid Trichogramma nr. brassicae

Abstract. 1. The effect of experience of plant cues at emergence on searching behaviour and parasitism was investigated in two strains of Trichogramma nr. brassicae (Hymenoptera: Trichogrammatidae).
2. Wasps reared on Sitotroga cereallela were allowed to emerge on a tomato plant or in a vial, with or without food. For one of the strains, females emerging on tomato searched significantly longer on a tomato seedling than females emerging in a vial.
3. The experience effect lasted between 1 and 2 days. It involves associating plant stimuli with the remains of the host, because females emerging from their host on a tomato plant had an increased searching response to tomato, but females transferred to the plant immediately after emergence did not.
4. The effect of emergence environment on parasitism of the host Helicoverpa punctigera on tomato and lettuce seedlings was tested. Wasps were allowed to emerge on seedlings of tomato or lettuce, or in an empty vial. For one strain, females experienced with tomato at emergence parasitized significantly more hosts on tomato than did females emerging on lettuce or in a vial. Parasitism on lettuce was not influenced by the treatments.     

Macrostructure of the tomato telomeres.

The macrostructure of the tomato telomeres has been investigated by in situ hybridization, genomic sequencing, and pulsed-field gel electrophoresis. In situ hybridizations with a cloned telomeric sequence from Arabidopsis thaliana indicated that the telomeric repeat of tomato cross-hybridizes with that of Arabidopsis and is located at all telomeres. Bal31 digestion kinetics confirmed that the tomato telomeric repeat represents the outermost DNA sequence of each tomato chromosome. Genomic sequencing of enriched tomato telomeric sequences, using primers derived from the Arabidopsis sequence, revealed that the consensus sequence of the tomato telomeric repeat is TT(T/A)AGGG compared with the Arabidopsis consensus sequence of TTTAGGG. Furthermore, as shown by pulsed-field gel electrophoresis, the telomeric repeat of tomato is separated by not more than a few hundred kilobases from a previously described 162-base pair satellite DNA repeat of tomato (TGR I) at 20 of the 24 telomeres. Together, these sequences are found in the heterochromatic terminal knob observed in pachytene chromosomes. Therefore, these two repeats determine the structure of 20 of the 24 tomato chromosome ends over approximately 2% of the total chromosome length.     

Assessment of transgene flow in tomato and potential effects of genetically modified tomato expressing Cry3Bb1 toxins on bumblebee feeding behaviour

One of the concerns surrounding the commercial release of genetically modified (GM) crops is the escape of transgenes into agricultural or semi‐natural habitats through vertical gene flow, as this may cause environmental or economic problems. There is also the concern that GM crops may affect pollinators and the pollination services they provide. Despite the growing commercial interest of GM tomato (Solanum lycopersicum), gene flow has been assessed only sparsely in tomato. To evaluate the likelihood of gene flow from GM tomato plants to sexually compatible plants, and to assess whether bumblebee activity is affected by GM tomato, three experiments were conducted under greenhouse conditions, using a Bt‐tomato expressing the insecticidal Cry3Bb1 protein as model system: (a) artificial crosses between a GM tomato line, two wild tomato relatives (Solanum hirsutum and Solanum nigrum) and a non‐GM tomato variety; (b) bumblebee‐mediated crosses between GM and non‐GM tomato plants and (c) visual observations of bumblebees' feeding behaviour. No hybrids were obtained between the GM tomato line and S. hirsutum and S. nigrum. In an experimental design where non‐GM receptor plants outnumbered GM plants by approximately 3:1, the bumblebee‐mediated cross‐fertilisation rate between GM and non‐GM tomato plants was measured at 4.3 ± 5.47%. No significant differences in feeding behaviour of bumblebees foraging on GM and non‐GM tomato plants were observed. Therefore, we conclude that: (a) the probability of transgene introgression between the GM tomato line used in this study and its wild relatives S. hirsutum and S. nigrum is negligible; (b) bumblebee activity can mediate cross‐fertilisation between GM and non‐GM tomato and (3) the Cry3Bb1‐expressing tomato line tested does not adversely affect the feeding behaviour of bumblebees.