The dormancy-breaking stimuli “chilling, hypoxia and cyanamide exposure” up-regulate the expression of α-amylase genes in grapevine buds

Published Date

15 March 2014, Vol.171(6):373–381, doi:10.1016/j.jplph.2013.11.009

Biochemistry

Title 

The dormancy-breaking stimuli “chilling, hypoxia and cyanamide exposure” up-regulate the expression of α-amylase genes in grapevine buds

• Author 

• Sebastián Rubio
• Amanda Donoso
• Francisco J. Pérez ^,

• Universidad de Chile, Facultad de Ciencias, Laboratorio de Bioquímica Vegetal, Casilla 653, Santiago, Chile

Received 29 July 2013. Revised 19 November 2013. Accepted 19 November 2013. Available online 5 February 2014.

Abstract

It has been suggested that respiratory stress is involved in the mechanism underlying the dormancy-breaking effect of hydrogen cyanamide (H₂CN₂) and sodium azide in grapevine buds; indeed, reductions in oxygen levels (hypoxia) and inhibitors of respiration promote bud-break in grapevines. In this study, we showed that, hypoxia increased starch hydrolysis soluble sugar consumption and up-regulated the expression of α-amylase genes (Vvα-AMYs) in grapevine buds, suggesting that these biochemical changes induced by hypoxia, may play a relevant role in the release of buds from endodormancy (ED). Three of the four Vvα-AMY genes that are expressed in grapevine buds were up-regulated by hypoxia and a correlation between changes in sugar content and level of Vvα-AMY gene expression during the hypoxia treatment was found, suggesting that soluble sugars mediate the effect of hypoxia on Vvα-AMYgene expression. Exogenous applications of soluble sugars and sugar analogs confirmed this finding and revealed that osmotic stress induces the expression of Vvα-AMY1 and Vvα-AMY3 and that soluble sugars induces Vvα-AMY2 and Vvα-AMY4gene expression. Interestingly, the plant hormone gibberellic acid (GA₃) induced the expression of Vvα-AMY3 and Vvα-AMY4 genes, while dormancy breaking stimuli, chilling and cyanamide exposure, mainly induced the expression of Vvα-AMY1 and Vvα-AMY2 genes, suggesting that these two α-amylase genes might be involved in the release of grapevine buds from the ED.

Abbreviations

BR₅₀, time required to reach 50% bud-break under forcing conditions

2DOG, 2 deoxi-glucose

6DOG, 6 deoxi-glucose

ED, endodormancy

GA₃, gibberellic acid

Glc, glucose

Fru, fructose

3MG, 3 methyl glucose

Suc, sucrose

Vvα-AMYs, Vitis vinifera α-amylase genes

Keywords

α-Amylase

Grapevine buds

Hydrogen cyanamide

Hypoxia

Sugar signaling

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Fig. 7.

• ⁎ 
  Corresponding author. Tel.: +56 2 9787249; fax: +56 22727363.

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Evaluation toxicity of monoterpenes to subterranean termite, Reticulitermes chinensis Snyder

Published Date

February 2014, Vol.53:163–166, doi:10.1016/j.indcrop.2013.12.021

Short communication

Title 

Evaluation toxicity of monoterpenes to subterranean termite, Reticulitermes chinensis Snyder

• Author 

• Yongjian Xie
• Kun Wang
• Qiuying Huang
• Chaoliang Lei ^,,

• Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, Huazhong Agricultural University, Wuhan 430070, PR China

Received 17 June 2013. Revised 7 December 2013. Accepted 14 December 2013. Available online 11 January 2014.

Highlights

• •
  Forty-two monoterpenes were evaluated for termiticidal activity toward Reticulitermes chinensis.
• •
  The (+)-pulegone and carvacrol were the most toxic monoterpenes to R. chinensis.
• •
  The termiticidal activity of oxygenated hydrocarbon was higher than the hydrocarbon.

Abstract

Monoterpenes can be used as potentially alternative pest control agents as well as good lead compounds for the development of new insecticides because of their safe, effective, and fully biodegradable characteristics. Different monoterpenes differ significantly in their toxicity to particular insects. We evaluated forty-two monoterpenes, including eleven monoterpene hydrocarbons and thirty-one oxygenated monoterpenes, for termiticidal activities toward Reticulitermes chinensis. In fumigation bioassays, the (+)-pulegone and carvacrol (ketones and phenols) were the most toxic monoterpenes to R. chinensis with LC₅₀ values of 0.003 and 0.007 μl/l, respectively. We found the termiticidal activities of oxygenated hydrocarbon compounds were higher than the hydrocarbon group. Our results suggest that (+)-pulegone and carvacrol are promising toxicants against R. chinensis and could be useful in the search for new natural termiticidal.

Keywords

• Monoterpenes
• Fumigation toxicity
• Reticulitermes chinensis
• Natural termiticidal

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Fig. 1.

 Table 1

Table 1.

• ⁎ 
  Corresponding author. Tel.: +86 27 8728 7207.
  
  

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Coumarins isolated from Esenbeckia alata (Rutaceae)

Published Date

February 2014, Vol.52:38–40, doi:10.1016/j.bse.2013.12.011

Title 

Coumarins isolated from Esenbeckia alata(Rutaceae)

• Author 

• Olimpo García-Beltrán ^a,,
• Carlos Areche ^a
• Bruce K. Cassels ^a
• Luis Enrique Cuca Suárez ^b

• aDepartment of Chemistry, Faculty of Sciences, University of Chile, Santiago, Chile
• bUniversidad Nacional de Colombia, Facultad de Ciencias, Departamento de Química, Laboratorio de Investigación en Productos Naturales Vegetales, Kr 30 Cl 45, Bogotá, D.C., Colombia

Received 12 August 2013. Accepted 14 December 2013. Available online 9 January 2014.

Highlights

• •
  Four furocoumarins were isolated from Esenbeckia alata.
• •
  3-(1′,1′-dimethylallyl)coumarins could be used as chemotaxonomic markers for family Rutaceae.
• •
  These compounds were reported for the first time from E. alata.

Keywords

• Esenbeckia alata
• Rutaceae
• Furocoumarins
• Chemotaxonomy

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Fig. 1.

• ∗ 
  Corresponding author.

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Reactivity of 2-(2-hydroxyphenyl)benzoxazole and 2-(2-hydroxyphenyl)benzothiazole towards group 10 transition metals. Evaluation in palladium catalyzed Suzuki?Miyaura C?C couplings

Published Date

24 May 2015, Vol.431:222–229, doi:10.1016/j.ica.2015.03.012

Advances in Transition Metal Catalysis

Title 

Reactivity of 2-(2-hydroxyphenyl)benzoxazole and 2-(2-hydroxyphenyl)benzothiazole towards group 10 transition metals. Evaluation in palladium catalyzed Suzuki–Miyaura C–C couplings

• Author 

• Hugo Valdés ^a
• Reyna Reyes-Martínez ^a
• J. Roberto Pioquinto-Mendoza ^a
• Alcives Avila-Sorrosa ^b
• Rubén A. Toscano ^a
• Simón Hernández-Ortega ^a
• David Morales-Morales ^a,,

• aInstituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, C.P. 04510, Mexico
• bDepartamento de Química Orgánica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala S/N, Colonia Santo Tomás, Mexico DF 11340, Mexico

Received 3 January 2015. Revised 8 March 2015. Accepted 10 March 2015. Available online 21 March 2015.

Highlights

• •
  A series of group 10 metal complexes with HPBO and HPBT were synthesized in a facile manner in moderate to high yields.
• •
  The palladium derivative of HPBO exhibited good catalytic activity in Suzuki–Miyaura couplings.
• •
  Depending on the metal the ligand HPBT exhibited up to four different coordination modes.
• •
  Depending on the metal the ligand HPBT may produce either coordination or organometallic species.
• •
  Studies in the solid state reveal important non-covalent interactions.

Abstract

A series of group 10 transition metal complexes based on 2-(2-hydroxyphenyl)benzoxazole (HPBO) and 2-(2-hydroxyphenyl)benzothiazole (HPBT) have been prepared. Reactions of nickel or palladium acetates with HPBT and HPBO produce chelate N–O coordinated compounds respectively. Whilst reaction of [K₂PtCl₄] with HPBT affords organometallic species product of a C–H bond activation of the phenolic moiety at room temperature. The molecular structures of the three complexes were unambiguously determined by means of single crystal X-ray diffraction analyses. The nickel compound [{Ni(κ²-N,O-HPBT)}₂(μ²-O-HPBT)₂(μ²-OOCCH₃)] (1) showing to be binuclear with the nickel ions found in six-coordinated distorted octahedral environments. Conversely, compound [Pd(κ²-N,O-HPBO)₂] (2) is a tetracoordinated monomer with the Pd center having a slightly distorted square planar geometry. Similarly, platinacycle [Pt(κ¹-N-HPBT)(κ²-N,C-HPBT)Cl] (3) shows the Pt center into a slightly distorted square planar geometry, exhibiting ligand HPBT in two different coordination modes, as single κ¹-N coordinated and as κ²-N-C metalated chelate bidentate ligand, completing the coordination sphere with a chloride ligand. The catalytic activity of the palladium complex (2) was evaluated in Suzuki–Miyaura cross couplings, showing good activity.

Graphical abstract

Group 10 metal complexes of 2-(2-hydroxyphenyl)benzoxazole (HPBO) and 2-(2-hydroxyphenyl)benzothiazole (HPBT) were prepared. Reactions with nickel or palladium acetates produce chelate N–O coordinated complexes and reaction of [K₂PtCl₄] with HPBT affords organometallic species via C–H bond activation. Crystal structures of the complexes were determined. The palladium complex was employed in Suzuki–Miyaura couplings.

Keywords

• 2-(2-Hydroxyphenyl)benzoxazole
• 2-(2-Hydroxyphenyl)benzothiazole
• Crystal structures
• Suzuki–Miyaura couplings
• C–H activation
• Catalysis

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Scheme 1.

Scheme 2.

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Fig. 2.

 Table 1

Table 1.

 Table 2

Table 2.

Scheme 3.

Fig. 3.

Scheme 4.

Fig. 4.

Fig. 5.

 Table 3

Table 3.

 Table 4

Table 4.

 Table 5

Table 5.

• ZIP (218K)

Supplementary data 1

• ZIP (117K)

Supplementary data 2

• ZIP (138K)

Supplementary data 3

• DOCX (600K)

Supplementary data 4

• ⁎ 
  Corresponding author. Tel.: +52 55 56224514; fax: +52 55 56162217.

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