The sand daffodil (Pancratium maritimum) is a perennial geophyte, widely distributed and grown in a wild stage along the Mediterranean seashores. The aboveground tissues of this geophyte are exposed to harsh, ambient conditions and its large inflorescences of remarkable beauty and fragrance expand during the drought season and carry particular ornamental worth. The ecophysiological principles underlining metabolic processes of this geophyte are poorly understood. The seasonal variation of soluble sugars, starch, and proline was investigated in individuals collected from patches of P. maritimum, therefore, monthly measurements were performed in bulbs, leaves, scapes, and petals during a year. It was found that (a) sugar content showed similar seasonal trends between bulbs and leaves, as well as between petals and scapes, (b) bulbs contained enhanced starch concentrations irrespective of season, (c) proline accumulation exhibited substantial seasonal fluctuations among the considered tissues and pronounced differences were detected between maxima in petals and leaves. A substantial increase in both sugar and proline content was evident in petals during the drought season. In leaves, the accumulation of proline and, to a lesser extent, sugars was negatively correlated to the precipitation of the Mediterranean study site. It seems likely that the astonishing flowering of P. maritimum is supported by large leaf and bulb reserves.Agronomy 2020, 10, 539 2 of 10 sandblasting [16,17]. In Greece, P. maritimum has been known for at least 2500 years [18]; the beautiful lily frescos in the palace of Knossos in Crete and at Akrotiri on Santorini island dating back approximately 2500 years have been identified as sea daffodils [19][20][21][22]. Additionally, the sea daffodil has been described in detail in ancient texts, such as Theophrastus' treatise (3rd century BC) [23] and Dioscorides' codex (1st century AD) [24]. It is worth mentioning that P. maritimum was included in the 4th volume of the 1st edition of Flora Graeca Sibthorpiana-one of the rarest and magnificent botanical books ever written [25]-that was published in London in 1823; this archival, rare source has been digitized and is currently electronically accessed [2,26]. Therein, the original watercolor made by the artist Ferdinand Bauer (1760-1826) in Oxford [26] was based on specimens collected during a botanical expedition in Greece, in 1787 [27,28].The etymology of the generic name Pancratium is derived from two Greek words, pan (παν) that means "all" and cratos (κράτoς) that means "potent" [29], hence Pancratium means omnipotent; in English, the meaning of maritimum is growing by the sea [29].Although several aspects concerning patterns of fruit and seed set within inflorescences, pollen, in vitro micropropagation, and genetic diversity of P. maritimum, as well as the extraction of natural substances from P. maritimum have been published [30][31][32][33][34][35][36][37][38], there is a scarcity of data on ecophysiological traits of the geophyte P. maritimum inh...

Climate change has influenced the transmission of a wide range of vector-borne diseases in Europe, which is a pressing public health challenge for the coming decades. Numerous theories have been developed in order to explain how tick-borne diseases are associated with climate change. These theories include higher proliferation rates, extended transmission season, changes in ecological balances, and climate-related migration of vectors, reservoir hosts, or human populations. Changes of the epidemiological pattern have potentially catastrophic consequences, resulting in increasing prevalence of tick-borne diseases. Thus, investigation of the relationship between climate change and tick-borne diseases is critical. In this regard, climate models that predict the ticks’ geographical distribution changes can be used as a predicting tool. The aim of this review is to provide the current evidence regarding the contribution of the climatic changes to Lyme borreliosis (LB) disease and tick-borne encephalitis (TBE) and to present how computational models will advance our understanding of the relationship between climate change and tick-borne diseases in Europe.

The geophyte Cyclamen graecum is native to the eastern Mediterranean. Its beautiful flowers with upswept pink petals appear during early autumn, after the summer drought period and before leaf expansion in late autumn. The floral and leaf development alternates with their cessation in early winter and late spring, respectively. Ecophysiological parameters and processes underlining the life-cycle of C. graecum have not previously been published. Seasonal fluctuations of sugars, starch, and free proline have been investigated in tubers, leaves, pedicels, and petals, as well as petal and leaf water status. At the whole plant level, the seasonal co-existence of leaves and flowers is marked by an elevated soluble sugar content, which was gradually reduced as the above-ground plant parts shed. The sugar content of petals and pedicels was lower than that of leaves and tubers. Leaf starch content increased from late autumn to spring and was comparable to that of tubers. The starch content in petals and pedicels was substantially lower than that of tubers and leaves. In tubers, monthly proline accumulation was sustained at relatively constant values. Although the partitioning of proline in various organs did not show a considerable seasonal variation, resulting in an unchanged profile of the trends between tubers, leaves, and flowers, the seasonal differences in proline accumulation were remarkable at the whole plant level. The pronounced petal proline content during the flowering period seems to be associated with the maintenance of floral turgor. Leaf proline content increased with the advance of the growth season. The values of leaf relative water content were sustained fairly constant before the senescence stage, but lower than the typical values of turgid and transpiring leaves. Relationships of the studied parameters with rainfall indicate the responsiveness of C. graecum to water availability in its habitat in the Mediterranean ecosystem.

A special feature found in Amaryllidaceae is that some guard cells of the neighboring stomata form a “connection strand” between their dorsal cell walls. In the present work, this strand was studied in terms of both its composition and its effect on the morphology and function of the stomata in Pancratium maritimum L. leaves. The structure of stomata and their connection strand were studied by light and transmission electron microscopy. FM 4–64 and aniline blue staining and application of tannic acid were performed to detect cell membranes, callose, and pectins, respectively. A plasmolysis experiment was also performed. The composition of the connection strand was analyzed by fluorescence microscopy after immunostaining with several cell-wall-related antibodies, while pectinase treatment was applied to confirm the presence of pectins in the connection strand. To examine the effect of this connection on stomatal function, several morphological characteristics (width, length, size, pore aperture, stomatal distance, and cell size of the intermediate pavement cell) were studied. It is suggested that the connecting strand consists of cell wall material laid through the middle of the intermediate pavement cell adjoining the two stomata. These cell wall strands are mainly comprised of pectins, and crystalline cellulose and extensins were also present. Connected stomata do not open like the single stomata do, indicating that the connection strand could also affect stomatal function. This trait is common to other Amaryllidaceae representatives.

Salinity is one of the most important factors influencing plant growth by participating in abiotic stress. Plants have developed a number of physiological mechanisms responding to abiotic stress. A well-studied response is the concentration of free proline and soluble sugars, which through various mechanisms enhances plant resistance to abiotic stress. What is less studied is that the mechanism of proline and sugars is present in other categories of organisms such as fungi. There are even less bibliographic data on a relationship of the mechanism of proline and soluble sugars accumulation in fungi. The purpose of this study is to investigate proline and soluble sugars accumulation in the fungus Aspergillus creber under salt stress tolerance.