The spectral properties of Hypericum perforatum leaves: the implications for its photoactivated defences

1990 ◽  
Vol 68 (5) ◽  
pp. 1166-1170 ◽  
Author(s):  
Paul G. Fields ◽  
John T. Arnason ◽  
R. Gary Fulcher
Keyword(s):  
Visible Light ◽  
Ultraviolet Light ◽  
Spectral Properties ◽  
Hypericum Perforatum ◽  
Herbarium Specimens ◽  
Artificial Diets ◽  
Hypericum Perforatum L ◽  
Hypericum Species

Unlike most other plant-derived phototoxins that are activated by ultraviolet light, hypericin from Hypericum species causes photoactivated damage by absorbing visible light (550–610 nm, maximum at 585 nm). Clear glands from Hypericum perforatum L. transmitted 66%, veins, 6% and the mesophyll, 1% of the light at 585 nm. When the total area of the various structures was taken into account, leaves transmitted approximately 2% of the light in the photoactive range of hypericin. Other studies have shown that this intensity of light is sufficient to cause light-induced mortality in insects fed on artificial diets containing hypericin. Having a phototoxin that is activated by the same wavelengths of light that are reflected and transmitted by plants may prevent insects from avoiding phototoxicity by simply hiding under or rolling leaves. However, a survey of herbarium specimens indicated that clear glands were not an obligate component of the photoactivated defences of Hypericum species.

The Effects of Herbivory by a Mite, Aculus hyperici, and Nutrient Deficiency on Growth in Hypericum Species

1995 ◽  
Vol 43 (3) ◽  
pp. 305 ◽  
Author(s):  
AJ Willis ◽  
JE Ash ◽  
RH Groves
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Hypericum Perforatum ◽  
Nutrient Deficiency ◽  
Combined Effects ◽  
Nutrient Deficiencies ◽  
Hypericum Perforatum L ◽  
Hypericum Species

The combined effects of herbivory by a mite, Aculus hyperici Liro, and a deficiency of nutrients on plant growth were measured for Hypericum perforatum L. and H. gramineum J.Forst. grown in a glasshouse. The results are discussed in relation to the biological control of H. perforatum, an introduced weed in southern Australia, relative to growth of its indigenous congener, H. gramineum. Growth of both species was reduced when infested with the mite, although the growth of H. perforatum was reduced by more than that of H. gramineum. Nutrient deficiencies also reduced growth of both species, especially of roots. Imposition of nutrient deficiency on mite-infested plants caused multiplicative reductions in plant growth equivalent to the product of the proportional reductions caused by either herbivory or nutrient deficiency alone.

scholarly journals Genetic diversity and relationships among Hypericum L. species by ISSR Markers: A high value medicinal plant from Northern of Iran

Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 97-107
Author(s):  
Shuyan Ma ◽  
Majid Khayatnezhad ◽  
Amir Abbas Minaeifar
Keyword(s):  
Hypericum Perforatum ◽  
High Capacity ◽  
Molecular Data ◽  
Issr Markers ◽  
Herbal Preparations ◽  
Inter Simple Sequence Repeats ◽  
Hypericum Perforatum L ◽  
Simple Sequence ◽  
Hypericum Species ◽  
Issr Primers

Hypericum L. species are generally known locally in Iran with the names “Hofariqun” which Ebn Sina (or Bo Ali Sina) called it. Plants of the genus Hypericum have traditionally been used as medicinal plants in various parts of the world. Hypericum perforatum L. is the source to one of the most manufactured and used herbal preparations in recent years, especially as a mild antidepressant. Therefore, due to the importance of these plant species, we performed a molecular data for this species. For this study, we used 175 randomly collected plants from 17 species in 9 provinces. Amplification of genomic DNA using 10 primers produced 141 bands, of which 127 were polymorphic (95.78%). The obtained high average PIC and MI values revealed high capacity of ISSR primers to detect polymorphic loci among Hypericum species. The genetic similarities of 17 collections were estimated from 0.617 to 0.911. According to Inter-Simple sequence repeats (ISSR) markers analysis, H. androsaemum and H. hirtellum had the lowest similarity and the species of H. perforaturm and H. triquetrifolium had the highest similarity. The aims of present study are: 1) can ISSR markers identify Hypericum species, 2) what is the genetic structure of these taxa in Iran, and 3) to investigate the species inter-relationship? The present study revealed that ISSR markers can identify the species. 

scholarly journals Differential phenolic accumulation in two Hypericum species in response to inoculation with Diploceras hypericinum and Pseudomonasputida

2014 ◽  
Vol 50 (No. 3) ◽  
pp. 119-128 ◽  
Author(s):  
C. Cirak ◽  
J. Radusiene ◽  
H.M. Aksoy ◽  
R. Mackinaite ◽  
Z. Stanius ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Hypericum Perforatum ◽  
Plant Defence ◽  
Defence Response ◽  
Phenolic Constituents ◽  
Plant Growth Promoting ◽  
Hypericum Perforatum L ◽  
Growth Promoting ◽  
Hypericum Species ◽  
Plant Defence Response

The genus Hypericum L. (St. John’s-wort, Hypericaceae) has received scientific interest in recent years, because it is a source of a variety of bioactive compounds including the phenolics. We determine whether the typical phenolic constituents of Hypericum plants, namely chlorogenic acid, rutin, hyperoside, isoquercetine, quercitrine, and quercetine, may be implicated as part of an inducible plant defence response in two St. John’s-wortspecies, Hypericum perforatum L. and Hypericum triquetrifolium Turra. To achieve this objective, greenhouse-grown plantlets were inoculated with the fungal pathogen Diploceras hypericinum and the plant growth promoting bacterium Pseudonomas putida. Phenolic compounds levels of the Hypericum plantlets increased significantly in response to inoculation with both organisms. So far, little effort has been dedicated to investigate whether phenolic compounds are inducible by pathogen/herbivore attack or if they could play a role in plant defence. Results from the study indicate that the phenolic compounds investigated could be involved in the plant defence system and implicated as part of an inducible plant defence response in both St. John’s Wort species.

The hyp-1 gene is not a limiting factor for hypericin biosynthesis in the genus Hypericum

2011 ◽  
Vol 38 (1) ◽  
pp. 35 ◽  
Author(s):  
Ján Košuth ◽  
Andrija Smelcerovic ◽  
Thomas Borsch ◽  
Sebastian Zuehlke ◽  
Katja Karppinen ◽  
...  
Keyword(s):  
Candidate Gene ◽  
Hypericum Perforatum ◽  
Limiting Factor ◽  
Gene Transcript ◽  
Coding Sequences ◽  
Key Enzyme ◽  
Hypericum Perforatum L ◽  
Hypericum Species ◽  
Dark Glands

Biosynthesis of the hypericins that accumulate in the dark glands of some members of the genus Hypericum is poorly understood. The gene named hyp-1, isolated from Hypericum perforatum L. has been proposed as playing an important role in the final steps of hypericin biosynthesis. To study the role of this candidate gene in relation to the production of hypericins, the expression of this gene was studied in 15 Hypericum species with varying ability to synthesise hypericin. While the accumulation of hypericins and emodin, an intermediate in the respective pathway, was associated with the dark glands in the hypericin-producing species, the hyp-1 gene was expressed in all studied species regardless of whether hypericins and emodin were detected in the plants. The coding sequences of hyp-1 cDNA were isolated from all species and showed more than 86% similarity to each other. Although, in general, an increased level of the hyp-1 gene transcript was detected in hypericin-producing species, several of the hypericin-lacking species expressed comparable levels as well. Our results question the role of the hyp-1 gene product as a key enzyme responsible for biosynthesis of hypericins in the genus Hypericum. The function of the hyp-1 gene may not be restricted to hypericin biosynthesis only, or some additional factors are necessary for completion of hypericin biosynthesis.

Antilipoxygenase activity of compounds from Hypericum perforatum

Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Marek Obložinský ◽  
Lýdia Bezáková ◽  
Ivana Holková ◽  
Marián Vanko ◽  
Thomas Kartnig ◽  
...  
Keyword(s):  
Hypericum Perforatum ◽  
Allergic Diseases ◽  
Inhibitory Effect ◽  
Biologically Active ◽  
Active Constituents ◽  
Ethanolic Extracts ◽  
Key Enzyme ◽  
Hypericum Perforatum L ◽  
Hypericum Species

AbstractThe main biologically active constituents of Hypericum species are flavonoids (quercetin, isoquercitrin, hyperoside, rutin), biflavonoids and naphthodianthrones (hypericin, pseudohypericin). Lipoxygenase is the key enzyme in the biosynthesis of leukotriens, which have been postulated to play an important role in the pathophysiology of several inflammatory and allergic diseases. This work deals with the investigation of potential antilipoxygenase activity of different compounds and extracts isolated from Hypericum perforatum L. The highest inhibitory effect was exhibited by flavonoid derivative hyperoside (IC50 5.768 × 10−6 M). Acetone and ethanolic extracts caused also an inhibition of lipoxygenase. On the basis of inhibitory effect of compounds tested we assume that the most of them may be involved in the antiinflammatory principles of Hypericum perforatum L.

Determination of Hypericin in St. John's Wort (Hypericum perforatum L.) extracts using HPLC-ED

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
E Sofic ◽  
A Copra Janicijevic ◽  
M Maksimovic ◽  
I Tahirovic ◽  
L Klepo ◽  
...  
Keyword(s):  
Hypericum Perforatum ◽  
St John’S Wort ◽  
St John's Wort ◽  
Hypericum Perforatum L
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