Homepage » Research » Recent Publications » Research Publications 2021


Costanza Dal Cin D’Agata & Sophia Rhizopoulou. 2021. "Cretan and Greek plants in Italian Renaissance gardens cited in archives" Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, DOI: 10.1080/11263504.2021.2013333, https://doi.org/10.1080/11263504.2021.2013333 Published online: 22 Dec 2021

Abstract: Cretan endemic and native Greek plants quoted in Italian archives, were being cultivated in botanic gardens from 15th to 17th century, when Crete was then under Venetian rule. A list that includes endemic, herbaceous, medicinal and aromatic plants, geophytes and ornamentals is presented. Conception of this influx of plants into renaissance botanic gardens and information about a rarely presented network of botanical exchange reveal regional and rational aspects of historical botany.

Foteini Kolyva, Sophia Rhizopoulou, Maria-Sonia Meletiou-Christou, and Emmanuel Stratakis. 2021. "Physiological Characteristics of Expanding and Expanded Leaves of Vitis vinifera L. cv. Assyrtiko in Climate Change Conditions" Biology and Life Sciences Forum 4, no. 1: 55. https://doi.org/10.3390/IECPS2020-08882


Abstract: The impact of climatic change on viticulture is expected to be severe in the Mediterranean area in the future. The scope of this study is the evaluation of the leaf functional and optical properties of grapevine (Vitis vinifera L.) cultivar (cv.) Assyrtiko and its response to abiotic stress conditions (elevated temperature and water deficiency) caused by climatic change. Plants of grapevine cv. Assyrtiko were placed in a growth chamber in the Botany Department of the National and Kapodistrian University of Athens, Greece and four indoor environmental treatments were applied, concerning temperature (ambient versus ambient +2 °C) and water availability (well-watered versus water stressed). The photosynthetic pigments (chlorophylls a and b and carotenoids) were determined as well as the leaf area, dry weight and specific leaf area in expanding and fully expanded leaves of the treated plants. Using a UV/VIS spectrophotometer (Perkin Elmer Lambda-950), equipped with an integrating sphere, the reflectance (R) and the transmittance (T), were measured in situ, between 250 and 2500 nm wavelength, in both adaxial and abaxial leaf surfaces of the grapevine cv. Assyrtiko and the absorbance (A) was calculated. It is likely that leaf chlorophyll content declined under drought and elevated temperature conditions.


Kourkoulou A, Zantza I, Foti K, Mikros E, Diallinas G. 2021 Context-dependent Cryptic Roles of Specific Residues in Substrate Selectivity of the UapA Purine Transporter.  J Mol Biol. 2021 Jan 23:166814. doi:10.1016/j.jmb.2021.166814.

Abstract: Members of the ubiquitous Nucleobase Ascorbate Transporter (NAT) family are H+ or Na+ symporters specific for the cellular uptake of either purines and pyrimidines or L-ascorbic acid. Despite the fact that several bacterial and fungal members have been extensively characterised at a genetic, biochemical or cellular level, and crystal structures of NAT members from Escherichia coli and Aspergillus nidulans have been determined pointing to a mechanism of transport, we have little insight on how substrate selectivity is determined. Here, we present systematic mutational analyses, rational combination of mutations, and novel genetic screens that reveal cryptic context-dependent roles of partially conserved residues in the so-called NAT signature motif in determining the specificity of the UapA transporter of A. nidulans. We show that specific NAT signature motif substitutions, alone and in combinations with each other or with distant mutations in residues known to affect substrate selectivity, lead to novel UapA versions possessing variable transport capacities and specificities for nucleobases. In particular, we show that a UapA version including the quadruple mutation T405S/F406Y/A407S/Q408E in the NAT signature motif (UapA-SYSE) becomes incapable of purine transport, but gains a novel pyrimidine-related profile, which can be further altered to a more promiscuous purine/pyrimidine profile when combined with replacements at distantly located residues, especially at F528. Our results reveal that UapA specificity is genetically highly modifiable and allow us to speculate on how the elevator-type mechanism of transport might account for this flexibility.

Sophia Papadopoulou, Sophia Rhizopoulou, Maria-Sonia Meletiou-Christou, and Emmanuel Stratakis. 2021. "Biomonitoring Air Pollution in Carob Leaves" Biology and Life Sciences Forum 4, no. 1: 50. https://doi.org/10.3390/IECPS2020-08896


Abstract: The optical properties and ecophysiological parameters of leaves of Ceratonia siliqua L. (carob) expanded in more and less polluted habitats were compared in order to evaluate the effect of air quality in leaf development. The accumulation of pigments (chlorophylls a and b, and carotenoids) and specific leaf area (SLA, cm2 g−1) were seasonally determined during leaf development (i.e., in nine successively grown leaves along shoots). Leaf transmittance (T) and reflectance (R) spectra for both adaxial and abaxial leaf surfaces were measured between 250 and 2500 nm wavelengths using a UV–VIS spectrophotometer and leaf absorptance (Abs) [(Abs = 100 − (R + T)] was used to assess the effect of environmental quality of more and less polluted habitats in Athens, according to the files of the Hellenic Ministry of Environment and Energy, on carob leaf physiology. An increase in the studied leaf parameters was observed for carob trees grown in the urban site. There was an increase in SLA from spring to late summer and a decrease in late autumn. Leaves of the less polluted site in the bush, regardless of the developmental stage, exhibited greater water absorption, while the adaxial surface absorbed more radiation in both categories of plants. It seems likely that differences in optical properties and pigment accumulation have important implications for model simulation purposes and may be used for air pollution biomonitoring.