Change of Several Plant Nutrient Elements by Plant Species and Organ

Nutrient elements, one of the major factors shaping plant development, are the major components of plants, and, after being taken from the soil, they are present in different organs of plant at different concentrations. The speciation of nutrient elements within plant body is vital importance for determining the contribution to plant development, knowing the transfer between organs within the body of organs, clearly understanding the factors influencing plant development, and shaping the plant development. In the present study, the change of the concentrations of K and Mg (macronutrient elements) and Cu (micronutrient elements) by species and organ in woody species Prunus cerasifera, Platanus orientalis, Acer negundo, Fraxinus excelsior, Catalpa bignonioides, Aesculus hippocastanum, and Tilia platypyllos. As a result, it was found that the changes of elements by species were statistically significant in all the organs, and, in general, the highest concentrations were observed in leaves. The study results revealed that the concentrations of these elements might significantly vary between the organs in the same species, which varies significantly by the species.

Change of Mg concentration in several plants depending on plant species, washing status, and traffic density

Air pollution is one of the most important problems threatening the organic life and ecosystem throughout the world. Among the components of air pollution, the most important ones are the heavy metals that can be toxic and carcinogenic even at low concentrations and even the nutrient elements can be harmful when at high concentrations. Thus, monitoring the heavy metal pollution in the air is very important and plants are widely used as biomonitor for this purpose. However, which plants and organs are more suitable for monitoring which heavy metal pollution can be determined with detailed studies. In the present study, it was aimed to determine which plant species and which organ of that species would be more suitable for monitoring the concentration of magnesium (Mg) in air. For this purpose, five organs of five species grown in regions having different traffic densities were examined. In conclusion, it was found that Mg concentration in washed bark of Robinia pseudoacacia, wood of Platanus orientalis, washed leaves of Ulmus minor, and non-washed leaves of Acer negundo and Nerium olender increased with increasing traffic density.

Revealing Soil and Tree Leaves Deposited Particulate Matter PTE Relationship and Potential Sources in Urban Environment

Trees play a pivotal role in improving urban environmental quality and provide several ecosystem services including the removal of pollutants from the air, such as particular matter (PM) and potentially toxic elements (PTE). Therefore, understanding the tree PM and PTE capturing potential, also in connection with plant species, is of great concern, especially in urban areas. This study aims to reveal the link between the elemental composition of PM deposited on tree leaves and soils PTE contents, as well as to rank the PM capturing efficiency of 10 different tree species growing under the impact of urban environments. This also allowed us to test the efficiency of PM deposited on tree leaves as a PTE biomonitoring and pollution source identification tool, in the two biggest urban areas of Armenia. Indeed, high contents of PTE are detected in both soil- and leaf-deposited PM from sites characterized by the presence of localized and active pollution sources (i.e., industrial unites, high traffic, etc.), which are identified by specific tracers (such as Mo, Cu, Zn, Pb, and Cd). Among the studied tree species, the highest PM amount per unit leaf area is observed for Platanus orientalis, but elm species are also identified as promising canditates to be considered for their PM removing potential, and need to be included in future more details studies.

In vivo evaluation of wound healing properties of Platanus orientalis L.

Background: According to the Iranian Traditional Medicine (ITM) references, Platanus orientalis L. possesses wound healing properties. Herein, we developed different topical formulations based on the ethanolic extract of P. orientalis leaves and evaluated its wound healing effects through an in vivo model. Methods: Hydroalcoholic extract of the leaves was obtained from ethanol 80% and it was evaluated for DPPH radical scavenging activity, total phenolic and flavonoid contents as well as the presence of tannins. Different topical formulations including ointment (D-O) and polymer film (D-F), were prepared and an in vivo test was run for 14 days in an excision wound model consisting of 5 groups of 6 rats. Results: Our results indicated the higher efficacy of D-O comparing with D-F, as wound surface area remarkably reduced within 14 days post-injury. Also, histological features including epitheliogenesis score, neovascularization, and collagen density indicated the potential wound healing effect of D-O. Conclusion: Wound healing properties of the ethanolic extract of P. orientalis leaves depended on the type of formulation and D-O was found to be much more potent than D-F, from reducing wound surface area, maximum epitheliogenesis score, proper neovascularization pattern, and early type I collagenization points of view.

First Report of a Phytopythium litorale Species Causing Crown and Root Rot on Rhododendron pulchrum in China

During a survey of pathogenic oomycetes in Nanjing, China from June 2019 to October 2020, at least ten adjacent Rhododendron pulchrum plants at a Jiangjun Mountain scenic spot showed symptoms of blight, and crown and root discoloration . Symptomatic root tissues collected from three 6-year-old plants were rinsed with water, cut into 10-mm pieces, surface sterilized with 70% ethanol for 1 min, and plated onto 10% clarified V8 PARP agar (cV8A-PARP) containing pimaricin (20 mg/liter), ampicillin (125 mg/liter), rifampicin (10 mg/liter), and pentachloronitrobenzene (20 mg/liter). Four Pythium-like isolates were recovered after three days of incubation at 26°C, and purified using hyphal-tipping. Ten agar plugs (2×2 mm2) of each isolate were grown in 10 mL of 10% clarified V8 juice (cV8) in a 10 cm plate at 26°C for 3 days to produce mycelial mats, and then the cV8 was replaced with sterile water. To stimulate sporangial production, three to five drops of soil extract solution were added to each plate. Sporangia were terminal, ovoid to globose, and the size is 24 to 45.6 (mean 34.7) (n=10.8) in length x 23.6 to 36.0 (mean 29.8) (n=6.2) in width. Gametangia were not observed in cV8A or liquid media after 30 days. For colony morphology, the isolates were sub-cultured onto three solid microbial media (cV8A-PARP, potato dextrose agar, corn meal agar) . All isolates had identical morphological features in the three media. Complete ITS and partial LSU and cox2 gene regions were amplified using primer pairs ITS1/ITS4, NL1/NL4, and FM58/FM66 , respectively. The ITS, LSU, and cox2 sequences of isolate PC-dj1 (GenBank Acc. No. MW205746, MW208002, MW208003) were 100.00% (936/936 nt), 100.00% (772/772 nt), and 99.64% (554/556 nt) identical to those of JX985743, MT042003, and GU133521, respectively. We built a maximum-likelihood tree of Phytopythium species using the concatenated dataset (ITS, LSU, cox2) to observe interspecific differences. Based on the morphological characters and sequences, isolate PC-djl was identified as Phytopythium litorale . As the four isolates (PC-dj1, PC-dj2, PC-dj3 and PC-dj4) tested had identical morphological characters and molecular marker sequences, the pathogenicity of the representative isolate, PC-dj1, was tested using two inoculation methods on ten one-year-old R. pulchrum plants. For the first inoculation method, plants were removed from the pot, and their roots were rinsed with tap water to remove the soil. Each of these plants was placed in a glass flask containing 250 mL of sterile water and 10 blocks (10 x 10 mm2) of mycelial mats harvested from a three-day-old culture of P. litorale, while the other plant was placed in sterile water as a control, and incubated at 26°C. After three days, symptoms including crown rot, root rot and blight was observed on the inoculated plants whereas the control remained asymptomatic. For the second inoculation method, ten plants were dug up to expose the root ball. Ten three-day-old cV8A plugs (5×5 mm2) from a PC-dj1 culture or sterile cV8A plugs were evenly insert into the root ball of a plant before it was planted back into the original pots. Both plants were maintained in a growth chamber set at 26°C with a 12/12 h light/dark cycle and irrigated as needed. After 14 to 21 days, the inoculated plant had symptoms resembling those in the field , while the control plant remained asymptomatic. Each inoculation method was repeated at triplicate and the outcomes were identical. Phytopythium isolates with morphological features and sequences identical to those of PC-dj1 were recovered from rotted crown and root tissues of all inoculated plants. Previously, P. litorale was found causing diseases of apple and Platanus orientalis in Turkey, fruit rot and seedling damping-off of yellow squash in southern Georgia, USA. This is the first report of this species causing crown and root rot on R. pulchrum, an important ornamental plant species in China. Additional surveys are ongoing to determine the distribution of P. litorale in the city of Nanjing.