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1.
Int J Mol Sci ; 21(23)2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33260627

RESUMO

Squamosa promoter binding protein (SBP)-box genes are plant-specific transcription factors involved in plant growth and development, morphogenesis and biotic and abiotic stress responses. However, these genes have been understudied in pepper, especially with respect to defense responses to Phytophthora capsici infection. CaSBP11 is a SBP-box family gene in pepper that was identified in our previous research. Silencing CaSBP11 enhanced the defense response of pepper plants to Phytophthora capsici. Without treatment, the expression of defense-related genes (CaBPR1, CaPO1, CaSAR8.2 and CaDEF1) increased in CaSBP11-silenced plants. However, the expression levels of these genes were inhibited under transient CaSBP11 expression. CaSBP11 overexpression in transgenic Nicotiana benthamiana decreased defense responses, while in Arabidopsis, it induced or inhibited the expression of genes in the salicylic acid and jasmonic acid signaling pathways. CaSBP11 overexpression in sid2-2 mutants induced AtNPR1, AtNPR3, AtNPR4, AtPAD4, AtEDS1, AtEDS5, AtMPK4 and AtNDR1 expression, while AtSARD1 and AtTGA6 expression was inhibited. CaSBP11 overexpression in coi1-21 and coi1-22 mutants, respectively, inhibited AtPDF1.2 expression and induced AtPR1 expression. These results indicate CaSBP11 has a negative regulatory effect on defense responses to Phytophthora capsici. Moreover, it may participate in the defense response of pepper to Phytophthora capsici by regulating defense-related genes and the salicylic and jasmonic acid-mediated disease resistance signaling pathways.

2.
J Agric Food Chem ; 65(30): 6114-6121, 2017 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-28683548

RESUMO

A series of new kresoxim-methyl derivatives, (pyridinylphenoxymethylene)phenyl methoxyiminoacetates, were synthesized and their structures were confirmed by NMR and high-resolution mass spectrometry (HRMS). Although derived from a fungicide, the bioassays indicated that several new compounds had good herbicidal activities. At 37.5 g a.i./ha, compound 5c showed 100% inhibition against Abutilon theophrasti, Amaranthus retroflexus, and Eclipta prostrata, which was better than mesotrione. Compound 5e had a broad herbicidal spectrum against broadleaf weeds. The present work indicates that 5c and 5e may serve as new candidates for potential herbicides.


Assuntos
Herbicidas/síntese química , Herbicidas/farmacologia , Fenilacetatos/química , Herbicidas/química , Metacrilatos/síntese química , Metacrilatos/química , Metacrilatos/farmacologia , Estrutura Molecular , Fenilacetatos/síntese química , Fenilacetatos/farmacologia , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Estrobilurinas , Relação Estrutura-Atividade , Controle de Plantas Daninhas
3.
Org Biomol Chem ; 15(27): 5709-5718, 2017 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-28650044

RESUMO

An asymmetric formal one-pot reaction of 4-hydroxycoumarins with unsaturated pyrazolones has been developed by merging a chiral bifunctional organocatalyst with molecular iodine, which furnished a series of optically active spiro[dihydrofurocoumarin/pyrazolone] heterocycles with spiro quaternary stereogenic centers in moderate to excellent yields (up to 99%) with excellent diastereoselectivities (up to >99 : 1 dr) and good to excellent enantioselectivities (up to 99% ee). The application in the gram-scale synthesis of chiral spiro[dihydrofurocoumarin/pyrazolone] compounds was also successfully realized.


Assuntos
Furocumarinas/síntese química , Pirazolonas/síntese química , Compostos de Espiro/síntese química , Ciclização , Furocumarinas/química , Estrutura Molecular , Pirazolonas/química , Compostos de Espiro/química
4.
Front Plant Sci ; 6: 755, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26442068

RESUMO

The plant-specific NAC (NAM, ATAF, and CUC) transcription factors have diverse role in development and stress regulation. A new transcript encoding NAC protein, homologous to nam-like protein 4 from Petunia was identified from an ABA-regulated subtractive cDNA library of Capsicum annuum seedling. Here, this homolog (named CaNAC2) from C. annuum was characterized and investigated its role in abiotic stress tolerance. Our results indicated that a plant-specific and conserved NAC domain was located in the N-terminus domain of CaNAC2 which was predicted to encode a polypeptide of 410 amino acids. Phylogenetic analysis showed that CaNAC2 belonged to the NAC2 subgroup of the orthologous group 4d. The protein CaNAC2 was subcellularly localized in the nucleus and it had transcriptional activity in yeast cell. CaNAC2 was expressed mainly in seed and root. The transcription expression of CaNAC2 was strongly induced by cold, salt and ABA treatment and inhibited by osmotic stress and SA treatment. Silence of CaNAC2 in virus-induced gene silenced pepper seedlings resulted in the increased susceptibility to cold stress and delayed the salt-induced leaf chlorophyll degradation. These results indicated that this novel CaNAC2 gene might be involved in pepper response to abiotic stress tolerance.

5.
BMC Plant Biol ; 14: 138, 2014 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-24885401

RESUMO

BACKGROUND: The pepper fruit is the second most consumed vegetable worldwide. However, low temperature affects the vegetative development and reproduction of the pepper, resulting in economic losses. To identify cold-related genes regulated by abscisic acid (ABA) in pepper seedlings, cDNA representational difference analysis was previously performed using a suppression subtractive hybridization method. One of the genes cloned from the subtraction was homologous to Solanum tuberosum MBF1 (StMBF1) encoding the coactivator multiprotein bridging factor 1. Here, we have characterized this StMBF1 homolog (named CaMBF1) from Capsicum annuum and investigated its role in abiotic stress tolerance. RESULTS: Tissue expression profile analysis using quantitative RT-PCR showed that CaMBF1 was expressed in all tested tissues, and high-level expression was detected in the flowers and seeds. The expression of CaMBF1 in pepper seedlings was dramatically suppressed by exogenously supplied salicylic acid, high salt, osmotic and heavy metal stresses. Constitutive overexpression of CaMBF1 in Arabidopsis aggravated the visible symptoms of leaf damage and the electrolyte leakage of cell damage caused by cold stress in seedlings. Furthermore, the expression of RD29A, ERD15, KIN1, and RD22 in the transgenic plants was lower than that in the wild-type plants. On the other hand, seed germination, cotyledon greening and lateral root formation were more severely influenced by salt stress in transgenic lines compared with wild-type plants, indicating that CaMBF1-overexpressing Arabidopsis plants were hypersensitive to salt stress. CONCLUSIONS: Overexpression of CaMBF1 in Arabidopsis displayed reduced tolerance to cold and high salt stress during seed germination and post-germination stages. CaMBF1 transgenic Arabidopsis may reduce stress tolerance by downregulating stress-responsive genes to aggravate the leaf damage caused by cold stress. CaMBF1 may be useful for genetic engineering of novel pepper cultivars in the future.


Assuntos
Adaptação Fisiológica , Arabidopsis/genética , Arabidopsis/fisiologia , Capsicum/metabolismo , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Adaptação Fisiológica/efeitos dos fármacos , Sequência de Aminoácidos , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Capsicum/genética , Temperatura Baixa , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Eletrólitos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Dados de Sequência Molecular , Fenótipo , Proteínas de Plantas/química , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ácido Salicílico/farmacologia , Plântula/efeitos dos fármacos , Plântula/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
6.
Chem Commun (Camb) ; 49(55): 6218-20, 2013 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-23736892

RESUMO

A novel Pd(OAc)2-NFSI-TFA system was developed for the highly selective ortho-monofluorination directed by diverse aryl-N-heterocyclic directing groups e.g., quinoxaline, pyrazole, benzo[d]oxazole, and pyrazine derivatives. A Pd(II/IV) catalytic cycle was proposed based on the ESI-MS/MS studies.

7.
J Org Chem ; 78(3): 1254-9, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23286458

RESUMO

The organocatalytic Michael reaction of ketones with γ-monohalonitrodienes catalyzed by chiral prolinethiol ether under solvent-free conditions was developed. The described method represents a novel approach for accessing highly functionalized monohaloalkenes with α, ß-stereocenters of up to >99% ee.


Assuntos
Alcenos/química , Alcenos/síntese química , Éter/química , Hidrocarbonetos Halogenados/química , Hidrocarbonetos Halogenados/síntese química , Prolina/química , Solventes/química , Compostos de Sulfidrila/química , Catálise , Estrutura Molecular , Estereoisomerismo
8.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 5): o1311, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22590216

RESUMO

In the title compound, C(14)H(23)N(3)O, the n-propyl group is disordered over two orientations with an occupancy ratio of 0.778 (3):0.222 (3). In the crystal, mol-ecules are linked by pairs of weak C-H⋯O inter-actions into inversion dimers with an R(2) (2)(14) graph-set motif.

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