Changes in phytohormone contents in chickpea seeds germinating under lead or zinc stress

The present work describes the changes that take place in phytohormone contents in germinating chickpea (Cicer arietinum cv. Aziziye-94) seeds in response to heavy metal stress. For this aim, endogenous abscisic acid (ABA), gibberellic acid (GA₃), zeatin (Z) and zeatin riboside (ZR) contents were followed for 24, 48 and 72 h in chickpea seeds germinating at the concentrations of 0.1, 1.0 and 5.0 mM Pb or 0.1, 1.0 and 10 mM Zn. The results showed that Pb and Zn significantly delayed and impeded the germination of chickpea seeds. The negative effect of Pb on germination was higher than that of Zn. Further, Pb increased ABA and Z contents while decreased GA₃ content in the germinating seeds. The high concentrations of Zn (1.0 and 10 mM) decreased contents of Z, ZR and GA₃ while 0.1 mM Zn increased the content of the same hormones. The ABA content was enhanced by Zn in all concentrations used.     

Transient changes in inflammatory and oxidative stress markers with total sleep deprivation

Sleep and Biological Rhythms - Sleep deprivation (SD) is known to modulate inflammatory and oxidative stress markers. How these markers change over the SD period have seldom been studied in healthy...     

A karyotypic study on Silene sect. Sclerocalycinae in Turkey

The karyology of fifteen taxa of Silene sect. Sclerocalycinae from Turkey has been investigated. Karyotype analyses has been carried out and the chromosome number of Silene caramanica, S. peduncularis, S. armena, S. laxa, S. swertiifolia, S. caesarea, S. sclerophylla, S. haradjianii and S. lycaonica have been determined for the first time. For all the taxa studied, the diploid chromosome number and the basic chromosome number were found to be 2n=24 and x=12, respectively. Except for S. chlorifolia and S. doganii, the karyomorphology of the taxa studied is here described for the first time. S. laxa was found to have the smallest chromosomes whereas the largest ones were observed in S. haradjianii. Silene chlorifolia had the highest A₁ index and S. bupleuroides subsp. bupleuroides had the highest interchromosomal asymmetry coefficient (A₂).     

Estimating effects of global warming from past range changes for cold demanding refugial taxa: A case study on South-west Anatolian species Poecilimon birandi

Although changes in biodiversity and in ecosystems are surely caused by a range of interacting drivers, such as natural or human-induced factors, one of the important drivers having major impacts on climate and biodiversity and leading to range changes and fragmentation is global warming. Defining past range changes/fragmentations during interglacial periods may provide tools to understand possible impacts of global warming on present biodiversity. To test this assumption we studied a marker gene in the bush-cricket Poecilimon birandi, a species confined to South-west Anatolia that demands a cold climate. Haplotypes of P. birandi constituted three main phylogroups,West, East and Demre. All haplotypes are unique to the respective phylogroup. An AMOVA suggested considerable divergence at all hierarchical levels. Though there is a strong isolation between phylogroups, the East and West groups harbour considerable haplotype diversity. Most of the demographic analyses suggest stable historical populations for the West and East phylogroups, but a coalescent-based demographic analysis indicates a bottleneck for the West phylogroup. The main conclusions are; (i) P. birandi contains considerable phylogenetic signal in 16S rDNA, (ii) there were at least three contemporaneous radiations, which might have originated from isolated refugial populations during Pleistocene, (iii) within a refugium, range changes induced by climatic shifts may be only vertical through an altitudinal gradient, (iv) significant genetic structure can arise in a small heterogeneous area, if the species requires particular habitats and has weak dispersal ability, (v) climatic shifts may cause fragmentation or extinction of populations, but can also lead to divergence of populations suffering from fragmentation, and (vi) altitudinal heterogeneity plays a buffering role, allowing for survival of the refugial biodiversity.     

Comparative bioinformatics analysis and abiotic stress responses of expansin proteins in Cucurbitaceae members: watermelon and melon

Protoplasma - Watermelon and melon are members of the Cucurbitaceae family including economically significant crops in the world. The expansin protein family, which is one of the members of the...     

Understudied regions and messy taxonomy: Geography,not taxonomy,is the best predictor for genetic divergence of the Poecilimon bosphoricus species group

The complex and dynamic history of the Anatolian Peninsula during the Pleistocene set the stage for species diversification. However, the evolutionary history of biodiversity in the region is shrouded by the challenges of studying species divergence in the recent, dynamic past. Here, we study the Poecilimon bosphoricus (PB) species group to understand how the bush crickets' diversification and the regions' complex history are coupled. Specifically, using sequences of two mitochondrial and two nuclear gene segments from over 500 individuals for a comprehensive set of taxa with extensive geographic sampling, we infer the phylogenetic and geographic setting of species divergence. In addition, we use the molecular data to examine hypothesized species boundaries that were defined morphologically. Our analyses of the timing of divergence confirm the recent origin of the PB complex, indicating its diversification coincided with the dynamic geology and climate of the Pleistocene. Moreover, the geography of divergence suggests a history of fragmentation followed by admixture of populations, suggestive of a ring species. However, the evolutionary history based on genetic divergence conflicts with morphologically defined species boundaries raising the prospects that incipient species divergences may be relatively ephemeral. As such, the morphological differences observed in the PB complex may not to be sufficient to have prevented homogenizing gene flow in the past. Alternatively, with the recent origin of the complex, the lack of time for lineage sorting may underlie the discord between morphological species boundaries and genetic differentiation. Under either hypothesis, geography—not taxonomy—is the best predictor of genetic divergence.