A novel mechanism of insect resistance engineered into tobacco

Hilder, Vaughan A.; Gatehouse, Angharad M. R.; Sheerman, Suzanne E.; Barker, Richard F.; Boulter, D.

doi:10.1038/330160a0

Cited by 852 publications

(354 citation statements)

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“…O mais claro exemplo disto é a produção de novo de fitoalexinas (compostos geralmente derivados de fenilpropanóides, mas também de terpenóides ou poliacetilenos) em resposta à invasão de patógenos 6,85,155,156 . Algumas plantas, como tomate e batata, em resposta à alimentação por insetos produzem rapidamente peptídeos inibidores de proteinase, o que pode diminuir significantemente a palatabilidade da planta ou parte dela 6,[157][158][159] .…”

Section: Indução Por Estímulos Mecânicos Ou Ataque De Patógenosunclassified

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

Gobbo‐Neto¹,

Lopes²

2007

Quím. Nova

913

364

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. do Café, s/n, 14040-903 Ribeirão Preto -SP, BrasilRecebido em 7/7/05; aceito em 11/4/06; publicado na web em 31/10/06 MEDICINAL PLANTS: FACTORS OF INFLUENCE ON THE CONTENT OF SECONDARY METABOLITES. Since secondary metabolites represent a chemical interface between plants and surrounding environment, their syntheses are frequently affected by environmental conditions. Thus, variations in the total content and/or of the relative proportions of secondary metabolites in plants can take place. We review the main environmental factors that can streamline or alter the production or concentration of secondary metabolites in plants. How seasonality, circadian rhythm, developmental stage and age, temperature, water availability, UV radiation, soil nutrients, altitude, atmospheric composition and tissue damage influence secondary metabolism are discussed.Keywords: variations in secondary metabolites; medicinal plants; chemical ecology. INTRODUÇÃODesde o quarto século a.C. existem relatos de normas para a coleta de plantas medicinais. Os carrascos gregos, por ex., coletavam suas amostras do veneno cicuta (Conium maculatum) pela manhã, quando os níveis de coniina são maiores 1,2 . Variações temporais e espaciais no conteúdo total, bem como as proporções relativas de metabólitos secundários em plantas ocorrem em diferentes níveis (sazonais e diárias; intraplanta, inter-e intraespecífica) e, apesar da existência de um controle genético, a expressão pode sofrer modificações resultantes da interação de processos bioquímicos, fisiológicos, ecológicos e evolutivos 3-7 . De fato, os metabólitos secundários representam uma interface química entre as plantas e o ambiente circundante, portanto, sua síntese é freqüentemente afetada por condições ambientais 8 .Os principais fatores que podem coordenar ou alterar a taxa de produção de metabólitos secundários estão expostos a seguir. Deve ser enfatizado, porém, que os estudos sobre influência destes fatores na produção de metabólitos secundários geralmente têm se limitado a um grupo restrito de espécies, predominantemente ocorrentes em regiões temperadas, muitas das quais são comercialmente importantes e podem ter sofrido fortes pressões seletivas antrópicas visando certas características desejadas. Seu comportamento, portanto, nem sempre é representativo de plantas selvagens ou de outros tipos de habitat.Também deve ser ressaltado que, muitas vezes, as variações podem ser decorrentes do desenvolvimento foliar e/ou surgimento de novos órgãos concomitante a uma constância no conteúdo total de metabólitos secundários. Isto pode levar à menor concentração destes metabólitos por diluição, podendo, no entanto, resultar em maior quantidade total, devido ao aumento de biomassa 9,10 . Além disso, alguns dos fatores discutidos apresentam correlações entre si e não atuam isoladamente, podendo influir em conjunto no metabolismo secundário, como por ex.: desenvolvimento e sazonalidade; índice pluviométrico e sazonalidade; temperatura e altitude, entre outros. FATORES QUE INFLUENCIAM O CONTEÚDO DE M...

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Section: Indução Por Estímulos Mecânicos Ou Ataque De Patógenosunclassified

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

Gobbo‐Neto¹,

Lopes²

2007

Quím. Nova

913

364

View full text Add to dashboard Cite

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“…In the latter case, if the affinity for insect digestive enzymes is also increased, then expression of processed forms would be desirable. A cowpea TI has been expressed in tobacco and shown to protect against insect attack [2,3], but the fate of the TI protein, as expressed in tobacco leaves, has not been investigated. Further 'trimming' of TI at N-and C-terminal ends may result in TI with increased potency.…”

Section: Discussionmentioning

confidence: 99%

“…The clearest example of such benefits is in transgenic plants, where resistance to insect attack has been demonstrated, as a result of transfer of heterologous trypsin inhibitor genes [2][3][4]. In addition, many enzyme inhibitors are proteins which are rich in sulphur-containing amino acids.…”

Section: Introductionmentioning

confidence: 99%

Multiple isoforms of Pisum trypsin inhibitors result from modification of two primary gene products

et al. 1995

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Characterization of Pisum (pea) seed trypsin inhibitors (TI) and their corresponding cDNAs indicates that the pea TI gene family contains two genes. The existence of multiple TI isoforms can be attributed to post-translational modifications of primary gene products. Post-translational processing at the Cterminus during the desiccation stage of seed development results in the appearance of TI isoforms with increased affinity for the target enzyme, trypsin.

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“…Similarly, it has been shown that one of the plant proteinase inhibitor (PI) genes can create resistance to several insect species. A good example was demonstrated by transferring a trypsin inhibitor gene from Vigna unguiculata to tobacco, where it conferred resistance to a wide range of herbivorous insects including lepidoptera, such as Heliothis and Spodoptera, coleoptera such as Diabrotica, Anthonomnous, and orthoptera such as Locusts (Hilder et al, 1987). Milligan et al (1998) isolated the Mi gene from tomato originally, due to its effect on pathogen root knot nematodes.…”

Section: Discussionmentioning

confidence: 99%

Two whitebacked planthopper resistance genes in rice share the same loci with those for brown planthopper resistance

et al. 2003

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The whitebacked planthopper (WBPH), Sogatella furcifera, and brown planthopper (BPH) Nilaparvata lugens Stå l are important sucking insects of rice (Oryza sativa L.) crops throughout the world. Rice 'B5', which has derived its resistance genes from the wild rice O. officinalis Wall ex Watt, is a line that is highly resistant to both WBPH and BPH. Previously, two resistance genes against BPH, Qbp1, and Qbp2 in 'B5' had been mapped onto chromosome 3 and chromosome 4, respectively. In this study, we employed a mapping population composed of 187 recombinant inbred lines (RILs), produced from a cross between 'B5' and susceptible variety 'Minghui63', to locate the WBPH and BPH resistance genes. A RFLP survey of the bulked extremes from the RIL population identified two genomic regions, one on chromosome 3 and the other on chromosome 4, likely containing the resistance genes to planthoppers. QTL analysis of the RILs further confirmed that two WBPH resistance genes were mapped on the same loci as Qbp1 and Qbp2, using a linkage map with 242 molecular markers distributed on 12 rice chromosomes. Of the two WBPH resistance genes, one designated Wbph7(t) was located within a 1.1-cM region between R1925 and G1318 on chromosome 3, the other designated Wbph8(t) was within a 0.3-cM region flanked by R288 and S11182 on chromosome 4. A two-way analysis of variance showed that two loci acted independently with each other in determining WBPH resistance. The results have significant implications in studying the interactions between sucking insects and plants and in breeding programs of resistance to rice planthoppers.

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A novel mechanism of insect resistance engineered into tobacco

Cited by 852 publications

References 0 publications

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

Plantas medicinais: fatores de influência no conteúdo de metabólitos secundários

Multiple isoforms of Pisum trypsin inhibitors result from modification of two primary gene products

Two whitebacked planthopper resistance genes in rice share the same loci with those for brown planthopper resistance

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