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The biochemical composition of Zygophyllum dumosum Boiss (Zygophyllaceae) was analyzed in petioles collected in the summer and winter from plants growing in a natural ecosystem on a southeast-facing slope of the Negev desert. UPLC-QTOF MS based analysis identified season specific sulfur containing phenylpropanoids unreported in plants. Sulfuric-caffeic and -ferulic acid derivatives and isorhamnetin 3-O-(4-sulfate-rutinoside) were measured to accumulate specifically in the summer. The reported identification and accumulation of sulfate containing metabolites during the hot and dry summer can be related to the putative protective role reported for these compounds.

In: Israel Journal of Plant Sciences

The sparsely distributed Limodorum abortivum is a European-Mediterranean orchid species, which grows on decomposing plant material. Although some chlorophyll-pigmentation is observed in the degenerated scales-shaped leaf and stems regions of the plant, its photosynthetic capacity is assumed to be insufficient to support the full energy requirements of an adult plant. In Israel, L. abortivum shows a patchy distribution patterns in the Galilee, Golan, Carmel and Judean regions. To gain more insights into the physiology and photosynthetic activity of L. abortivum, we analyzed the organellar morphologies, photosynthetic activities the chloroplast-DNA sequence by Illumina-HTS. Microscopic analyses indicated to the presence of mature chloroplasts with well-organized grana-thylakoids in the leaves and stems of L. abortivum. However, the numbers of chloroplasts per cell and the grana ultrastructure density within the organelles were notably lower than those of model plant species and fully photosynthetically-active orchids. The cpDNA of L. abortivum (154,954 bp) encodes 60 proteins, 34 tRNAs and 4 rRNAs. The coding-regions of 24 genes are interrupted by 26 group-II intron-sequences. While many genes related to photosynthesis (RuBisCo, PSI, PSII and cytochrome b 6 /f subunits) have remained intact in the cpDNA, the majority of the NADH-dehydrogenase (ndh) subunits were either lost or became nonfunctional (i.e. pseudogenized). In agreement with previous reports, the photosynthetic-rates of adult Limodorum plants were found to be very low, further indicating that carbon-assimilation activity is insufficient to support the energy requirements of an adult plant, and may suggest that L. abortivum have adopted nutritional strategies similar to that of mycoheterotrophic orchid species.

In: Israel Journal of Plant Sciences

Several types of defensive Batesian mimicry seem to be much more common in plants than was historically and is currently considered. It is based either on visual aspects (shape, coloration, and even movement), on odors, and on combinations of both these sensing modalities. Various characters that seem to function as defensive Batesian mimicry, may also simultaneously take part in pollination, physiological functions, or in other defensive mechanisms. The defended models for the visual Batesian mimics in plants belong to several categories: (1) spiny, thorny and prickly plant species, (2) mechanically or chemically defended parts of the same individual plant, or other members of the same species (auto mimicry), (3) colorful and chemically defended plants, (4) dangerous animals (aggressive, toxic), (5) fungal attacks, (6) animal action and animal damage cues, and (7) oozing defensive white latex. Olfactory defended models include: (1) toxic plants, (2) animal alarm pheromones, and (3) animal carrion and feces odors. Many more descriptive, genetic, phylogenetic and experimental studies have to be done in order to better understand the role of defensive Batesian mimicry in plant biology.

In: Israel Journal of Plant Sciences
In: Israel Journal of Plant Sciences

Germination behavior of the widespread southeastern Mediterranean shrub Sarcopoterium spinosum was conducted to assess its respond to post-fire cues. Germination experiments were conducted on 10 populations along a rainfall gradient – from productive, fuel-rich and fire-prone mesic Mediterranean populations, as well as from those in arid and fuel-poor environments. Our results indicate that post-fire cues induced germination of S. spinosum only among populations that originated from sites that are prone to wild fires. As wild-fires in this region occur mainly during the long dry season, but rarely ignited by natural factors, the adaptation to human made fires in natural populations of the southeastern Mediterranean environments is discussed.

In: Israel Journal of Plant Sciences

Plants thriving in harsh desert environments provide a suitable bio-system for unraveling novel mechanisms for survival under seasonal climate change and combination of temperature extremes, low water and nutrient availability and high salinity and radiation levels. The study of the desert plant Zygophyllum dumosum Boiss in its the natural habitat of the Negev desert revealed that stress tolerance is achieved by a plethora of mechanisms (e.g. morphological, molecular and developmental mechanisms), which are probably regulated by multiple genes that act together to bring about tolerance. Of particular interest is the finding that Z. dumosum like other Zygophyllaceae species, most of which inhabit dry and semidry regions of the world, do not possess the repressive epigenetic markers of histone H3 di- and tri-methylated at lysine 9; yet they possess mono methyl H3K9. We discuss the adaptive value of lessening epigenetic constraints with regard to the opportunistic behavior that makes plants most adaptable to change.

In: Israel Journal of Plant Sciences

Molecular tools provide new insights into phylogenetic relationships of plant species, and by relating phylogenetic groups to their geographical distribution, we can cast light upon the evolution history of plant clades. In the current study, we evaluated the phylogenetic position of the Sinai endemic Brassica deserti (Brassicaceae), later renamed as Erucastrum deserti, based on morphological data and 5.8S rDNA and ITS (Internal Transcribed Spacer) regions. Our results indicate that B. deserti belongs to an East-Mediterranean – Saharo Arabian clade and was not assigned to the core Brassica and Erucastrum clades, respectively, which evolved in the West Mediterranean area. We tentatively conclude that Brassica deserti evolved independently of core Brassica and Erucastrum.

In: Israel Journal of Plant Sciences

The following contribution focuses on Assyrian stone reliefs depicting winged figures holding a bucket and reaching a cone-shaped object toward a stylized tree. Ever since the discovery of the reliefs, the cone-shaped object was considered as either a conifer cone or a date palm male inflorescence used in the symbolic pollination of the stylized tree, derived from the date palm. Utilizing the visual material combined with textual evidence and based on the importance of the date palm as economic resource that gave rise to a plethora of meanings, religious, royal and popular, I shall argue that the scene refers to the artificial pollination of the tree.

In: Israel Journal of Plant Sciences

Over the last century, crosstalk between archaeologists and botanists had focused on the identification of plants remnants, such as charcoal or seeds found in archaeological inventory. Here we demonstrate how botany can play a fundamental role in identifying ancient landscape by using current vegetation. Identifying the loci of ancient human activity is the initial step of any archaeological study, enabling analyses such as settlement patterns, economic structures and land use, as well as devising excavations strategy. While mounds (tells) are standing out of their surroundings and are easily detected, other sites are hidden underground, and require various methods for detection. The cost and intensity of these methods vary, but most are time-consuming, require a team of specialists, and show somewhat limited success, leading archaeologists to seek new methods of site detection. Here, we describe a study of vegetational parameters at Tel ‘Eton (Israel), located in a semi-arid climatic region, where vegetation is mostly herbaceous, mainly comprised of annual plants. We compared above ground biomass, species richness and species composition among four plots in Tel ‘Eton and its surrounding. Two plots were located where ancient settlement found in a previous study, one on top of the mound and one below, where a “lower city” was previously identified. The other two plots were located in similar topographies, namely one on a hill and the other below, but in never-settled areas. While above ground biomass was similar between settled and not-settled plots, species richness was significantly higher in settled plots (40 and 32 species in settled plots, versus 28 and 9 species in non-settled) and species composition was significantly different between them. Our results demonstrate that loci of buried remains of human activity significantly differ from non-settled ones, hence providing the basis for an above ground indirect method of identification of human remains. We propose that floristic sampling of ground-level vegetation may allow archaeologists to identify buried sites, and hence increase the validity of various types of archaeological analyses, such as creating maps of settlements, which rely on the identification of sites without excavating them.

In: Israel Journal of Plant Sciences