Floral traits and reproductive success variation among inflorescence orders in Eryngium maritimum

Simulation analyses of the evolution of intra-inflorescence flowering patterns assuming selection on anthesis interval among individual flowers

What conditions select flowering patterns within inflorescences, or variation in the anthesis interval within inflorescences among plants? Under what conditions are gradual blooming and simultaneous blooming, both traits related to floral display size, advantageous? We constructed a simulation model in which the opening times and longevities of individual flowers within inflorescences, the sizes of attractive structures of individual flowers, and the numbers of ovules and pollen grains produced by individual flowers evolve. Individual plants in the population compete for pollinators, and plants are selected by pollinators according to their floral display sizes and amounts of resources allocated to attractive structures. We found that, if the proportion of pollen on a pollinator deposited on a stigma was low, gradual blooming did not evolve even if inbreeding depression was greater than 0.5. This is because the amount of outcross-pollen on pollinators decreased at a low rate during flower visits within a single inflorescence, and the selfing rate was suppressed to a low level even if the floral display size was large. On the other hand, if the proportion of pollen deposition was high, gradual blooming evolved even if inbreeding depression was smaller than 0.5. This may be because gradual blooming can enhance pollen delivery to other plants by reducing the loss of self-pollen by geitonogamy. On the other hand, allocation ratios among floral organs (female and male organs and attractive structures) were independent of the degree of simultaneous and gradual blooming within inflorescences. We concluded that the evolution of gradual blooming is more strongly affected by the proportion of pollen on a pollinator deposited on a stigma than by inbreeding depression.

Insights on physiological, antioxidant and flowering response to salinity stress of two candidate ornamental species: the native coastal geophytes Pancratium maritimum L. and Eryngium maritimum L

Increasing seawater influence in coastal areas is an ongoing environmental issue. Gardening is a widespread activity mainly in touristic areas such as the Mediterranean coasts. However, the use of exotic species well adapted to salinity encompasses the risk of invasive species introduction. This study aimed to evaluate salinity tolerance of native geophytes, Pancratium maritimum L. and Eryngium maritimum L., to assess their use as ornamental species in salt affected coastal areas. Experiments were conducted using cultivated plants for flowering response and physiological and enzymatic antioxidant response. Six treatments were applied for two months, exposing plants to seawater (SW) dilutions (Tap-Water, 6.25%SW, 12.5%SW, 25%SW, 50%SW and 100%SW). Taxa decreased inflorescence production being this effect more architectonical in E. maritimum and affecting all inflorescence integrity in P. maritimum. Flowering time was strongly delayed and reduced in P. maritimum, while E. maritimum showed smaller effects among treatments. Physiological and biochemical response showed at moderate salinity levels (1/4SW) variation concomitant with late stress response and senescence in P. maritimum, with decreased water use efficiency, NPQ values, and enzymatic activity, and increased malondialdehyde (MDA) levels. In contrast, E. maritimum showed early stress response with steady gas exchange response, increasing NPQ values and catalase (CAT) and superoxide dimutase (SOD) activity, and decreasing MDA levels with salinity. Glutathione enzymes showed limited participation in both species. The results of this study suggest that neither species can be classified as halophytes, but they exhibit tolerance to low and moderate salinity levels, making them suitable for ornamental use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-024-01502-0.

Formal analyses are fundamental for the definition of honey, a product representing specific territories and their changes: the case of North Tyrrhenian dunes (Italy)

Honey is a variegate matrix depending significantly on the floral origin, and it could become an important agri-food product to valorise specific territories. Being so diverse, different analytical techniques are necessary for its description. Herein we characterized the honey produced in one of the Italian sand dunes systems hosting beekeeping activities. In terms of floristic origin, phytochemical characterization, and sensory and colour analysis, honey collected in 2021 and 2022 was comparable. Honey was polyfloral, with several pollens from dune habitat plants classified as minor. The presence of the allochthonous Amorpha fruticosa L. and the ruderal Rubus fruticosus L. pollens in the category of the secondary pollens testifies the alteration of the park vegetation. The phytochemical profile was rich in polyphenols. Other interesting compounds were coumarine derivatives, likely attributable to resin-laden plants as rockroses, long chain hydroxyacids typical of royal jelly and nicotinic acid and its analogues (2-hydroxynicotinic acid and 2-hydroxyquinoline). The above-mentioned honey showed interesting features and was a good representation of the vegetation of this area. Our study pointed out the importance of relying on multiple analytical techniques for the characterization of honey and the advisability of a technical support toward beekeepers to correctly describe and valorise their product.

Antioxidant and anti-inflammatory potential of rhizome aqueous extract of sea holly (Eryngium maritimum L.) on Jurkat cells

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Eryngium is known for producing a wide range of bioactive compounds with proved medicinal properties. In the last years, research has focused on E. maritimum, with previous studies reporting anticancer, antimicrobial, antioxidant, and anti-inflammatory activities. Ethnobotanical literature suggests that it has been traditionally used to treat a wide range of illnesses, having antitussive, diuretic and aphrodisiac properties. Being rhizome one of the most bioactive organs, much of the available references from traditional uses suggest that it has been specifically used to treat renal diseases. In this sense, inflammation and oxidative processes play a major role in kidney dysfunctions, which could be associated to the mechanism of action of the plant extracts.

AIM OF THE STUDY

The main aim of the study was to investigate the effects of E. maritimum rhizome extract on the antioxidant and inflammatory response in human immune cells.

MATERIAL AND METHODS

Rhizome extracts were obtained from plants growing in Mallorca (Balearic Islands), and its composition was determined using HPLC-DAD, highlighting simple phenolic compounds such as trans-ferulic acid, catechin, chlorogenic acid, epicatechin and rosmarinic acid as the major constituents. Total antioxidant capacity was determined using the FRAP assay. Jurkat cells were cultured to analyse cytotoxicity by cell viability assay. In parallel, cells were stimulated with phytohemagglutinin and treated with different extract concentrations. Gene and protein expression, as well as nitrite and cytokine levels were evaluated as indicators of metabolic responses.

RESULTS

The plant extract showed a high diversity of pharmacologically bioactive compounds with potential therapeutic uses. The extract presented null cytotoxicity and exerted antioxidant and anti-inflammatory effects on Jurkat cells by inducing an antioxidant response and reducing cytokine and nitric oxide release and the expression of pro-inflammatory genes.

CONCLUSION

The present findings suggest that E. maritimum is a promising phytotherapeutic species because of its strong antioxidant and anti-inflammatory potential, which could explain some of its traditional uses.

The role of E. maritimum (L.) in the dune pollination network of the Balearic Islands

Eryngium maritimum L. (Apiaceae) is a geophyte that inhabits in the dunes of the Mediterranean and Atlantic. Although it is a highly entomophilous species, there is little literature on its pollinator assemblage. The aim of this study is to analyze the role played by E. maritimum in the dune pollination network of the Balearic Islands, where there is an intense anthropogenic impact in its habitat. For this purpose, two populations located in the North and South of Mallorca were chosen, in which diurnal transects were carried out to observe and capture pollinators on 15 plant species during the anthesis period of E. maritimum. The flowering period of 10 plant species flowering at the same period than E. maritimum was analyzed to identify periods of competition. A total of 71 pollinator species were found, belonging to 30 different families. Eryngium maritimum is a strongly generalist species, with a total of 45 pollinator species. Two new species, Odice blandula and Leucospis gigas, were found for the first time in Mallorca. In terms of pollinators, Teucrium dunense and Helichrysum stoechas are the most similar species to E. maritimum. However, analysis of phenology suggests that these three species have been able to decouple their blooms to avoid competition. The present study shows that E. maritimum plays an important role in the dune pollination network, being its anthesis located at the end of the dune flowering season, when there are no functionally similar species in flower.