Plant Body Research Articles

Effect of Soil Water Contents on Arsenic Accumulation in Phytoliths of Pteris multifida and Phragmites australis

The accumulation of metal(loid)s in phytoliths can physically immobilize the toxic materials and reduce toxicity in plant bodies and soil. Spider brake (Pteris multifida) is a well-known As hyperaccumulator that also harbors phytolith. However, As accumulation in phytoliths has not yet been studied with P. multifida. Soil water content is considered the main factor influencing phytolith accumulation. In this study, the As concentration in the phytoliths of P. multifida was compared with that in common reed (Phragmites australis) phytoliths with various soil water content. The range of As concentration in the phytoliths of P. multifida was 414.70–1610.74 mg kg−1, and the range for P. australis phytoliths was 41.67–126.54 mg kg−1. In P. multifida, higher soil water content increased As accumulation in the phytolith but did not affect the phytolith content in the plant. In P. australis, the higher soil water content increased phytolith content in the plant but decreased As concentration in phytoliths. This study suggests that P. multifida has higher As content in phytoliths than P. australis, and this accumulation can be affected by soil water content. The current findings provide how As encapsulated in phytolith and detoxified in different plants and conditions.

Foliar application of silver nanoparticles mitigated nutritional and biochemical perturbations in chilli pepper fertigated with domestic wastewater

Due to environmental pollution, crop growth and productivity are threatened at different levels. Recapitulation of changes in plant bodies due to water pollution and mitigating strategies reveal the need for précised actions to save crop losses. The present study was carried out to estimate modulations in growth, mineral homeostasis, and nutrient profile of fruits in Capsicum annum L. grown with three concentrations of wastewater (25, 50, 100%) and two levels of silver nanoparticles (40 and 80 mg/L AgNPs). It has been reported that ion accumulation patterns from wastewater clearly vary among crops. Our findings manifested that the application of AgNPs significantly improved the mineral ions in different plant tissues, that ultimately helped to improve growth. Highest improvements were recorded for root shoot P (316 and 197%) at T9 (80 mg/L AgNPs + normal water), while K (273 and 262%), Mg (638 and 916%), and Ca (148 and 273%), at T11 (80 mg/L AgNPs + 50% Wastewater), in comparison with control. Such reduction in elemental uptake that remain detrimental even at low concentrations positively correlates with growth and nutrition of Capsicum plants. Another facet of our observation is dose-dependent improvement in nutritive attributes of fruits i.e., crude fibers, proteins, and carbohydrates by AgNPs. T8 (40 mg/L AgNPs + 100% Wastewater), improved nutritional attributes such as P (55%), Mn (44%), Zn (38%), Carbohydrates (62%), Crude fat (38%), and Fibers (49%) as compared to control. Application of silver nanoparticles (AgNPs) combined with untreated wastewater (WW) reduced the hazards of contaminants in plants. The finding of the current study suggested that AgNPs are a cost-efficient and environment friendly material having the potential to mitigate harmful impacts of WW on plants.

Biomolecular Strategies for Vascular Bundle Development to Improve Crop Yield.

The need to produce crops with higher yields is critical due to a growing global population, depletion of agricultural land, and severe climate change. Compared with the "source" and "sink" transport systems that have been studied a lot, the development and utilization of vascular bundles (conducting vessels in plants) are increasingly important. Due to the complexity of the vascular system, its structure, and its delicate and deep position in the plant body, the current research on model plants remains basic knowledge and has not been repeated for crops and applied to field production. In this review, we aim to summarize the current knowledge regarding biomolecular strategies of vascular bundles in transport systems (source-flow-sink), allocation, helping crop architecture establishment, and influence of the external environment. It is expected to help understand how to use sophisticated and advancing genetic engineering technology to improve the vascular system of crops to increase yield.

Bodies That Cohere: Notes on Ganja and Gender in Colonial India

This essay explores what might result if histories of empire and colonialism took the material relationships of human and plant bodies as a fundamental framework. Gender both structured, and was reproduced through, various relationships shaped by collisions between British imperialism and the natural and social worlds of colonial India. Taking up the mutually constitutive formation of the sexuality of a plant body and the body of the sex worker in colonial India, this essay attempts to analyse gender more expansively beyond human bodies marked by colonial rule. It examines how labour, performed as sex work as well as floral sex work, formed an axis around which gendered relationships could cohere over time. It argues that placing the plant, its sexuality and its scaffolding botanical frameworks on the one hand, and anxieties of colonial patriarchal arrangements on the other, can further complicate and deepen a historical analysis of colonialism in South Asia.

Molecular Mechanisms Underlying the Establishment and Maintenance of Vascular Stem Cells in Arabidopsis thaliana.

The vascular system plays pivotal roles in transporting water and nutrients throughout the plant body. Primary vasculature is established as a continuous strand, which subsequently initiates secondary growth through cell division. Key factors regulating primary and secondary vascular developments have been identified in numerous studies, and the regulatory networks including these factors have been elucidated through omics-based approaches. However, the vascular system is composed of a variety of cells such as xylem and phloem cells, which are commonly generated from vascular stem cells. In addition, the vasculature is located deep inside the plant body, which makes it difficult to investigate the vascular development while distinguishing between vascular stem cells and developing xylem and phloem cells. Recent technical advances in the tissue-clearing method, RNA-seq analysis and tissue culture system overcome these problems by enabling the cell-type-specific analysis during vascular development, especially with a special focus on stem cells. In this review, we summarize the recent findings on the establishment and maintenance of vascular stem cells.

Taxonomic studies on the genus Delphinium (Ranunculaceae) from China (XXII): Clarifying morphological distinction between D. drepanocentrum and D. umbrosum and synonymizing D. umbrosoides with D. drepanocentrum

Based on critical observations on herbarium specimens (including type material), we demonstrate that Delphinium drepanocentrum (Ranunculaceae), an eastern Himalayan species distributed in Bhutan and China (southern Xizang), is most readily distinguishable from D. umbrosum, a species endemic to northwestern Yunnan, China, by an array of morphological characters, particularly by the indumentum on plant body. Our results support the treatment of D. drepanocentrum as an independent species. Moreover, some collections from Cona in southern Xizang previously cited as D. umbrosum var. drepanocentrum or misidentified as D. umbrosum subsp. drepanocentrum on the determination slips are determined not to belong to D. drepanocentrum, but represent a hitherto undescribed species. Furthermore, D. umbrosoides, described recently from Xizang, is determined to be conspecific with D. drepanocentrum and thus is synonymized herein. Finally, we pointed out that D. umbrosum var. hispidum is identical with D. omeiense, a species distributed in southwestern Sichuan and northeastern Yunnan, China.

Dynamics of Vegetation Productivity in Relation to Surface Meteorological Factors in the Altay Mountains in Northwest China

Vegetation productivity, as the basis of the material cycle and energy flow in an ecosystem, directly reflects the information of vegetation change. At the ecosystem level, the gross primary productivity (GPP) refers to the amount of organic carbon fixed by plant bodies. How to accurately estimate the spatiotemporal variation of vegetation productivity of the forest ecosystem in the Altay Mountains in northwest China has become a critical issue to be addressed. The Altay Mountains, with rich forest resources, are located in a semi-arid climate zone and are sensitive to global climate changes, which will inevitably have serious impacts on the function and structure of forest ecosystems in northwest China. In this paper, to reveal the variation trends of vegetation gross primary productivity (GPP) and its response to surface meteorological factors in the Altay Mountains in northwest China, daily temperature and precipitation data from the period of 2000–2017 were collected from seven meteorological stations in Altay prefecture and its surrounding areas; the data were analyzed by using the MODIS GPP model, moving average trend analysis, linear regression analysis and the climate tendency rate method. The results show that: (1) The spatial distribution pattern of GPP in the whole year was almost the same as that in the growing season of vegetation in the Altay Mountains. In the whole mountain range, the proportion of the area which had a GPP value of 400–600 g c/m2 had the highest value; the proportion of the annual and growing season of this area was 41.10% and 40.88%, respectively, which was mainly distributed in the middle and west alpine areas of the Altay Mountains. (2) There was a big gap in the GPP value in the different stages of the vegetation growing season (April to September), which reached the highest value in July, the area with a GPP of 100–150 g c/m2 was the highest, with 36.15%. (3) The GPP of the Altay Mountains showed an overall increasing trend, but the annual fluctuation was relatively large. In 2003, 2008, 2009 and 2014, the GPP showed lower values, which were 385.18 g c/m2, 384.90 g c/m2, 384.49 g c/m2 and 393.10 g c/m2, respectively. In 2007, 2011 and 2016, the GPP showed higher values, which were 428.49 g c/m2, 428.18 g c/m2 and 446.61 g c/m2. (4) In 64.85% of the area of the Altay Mountains, the GPP was positively correlated with annual average temperature, and in 36.56% of the area, the correlation coefficient between temperature and GPP ranged from −0.2 to 0. In 71.61% of the area of the Altay Mountains, the GPP was positively correlated with annual accumulated precipitation, and in 28.39% of the area, the GPP was negatively correlated with annual accumulated precipitation. Under the scenario of global climate change, our study has quantitatively analyzed the long-term dynamics of vegetation GPP and its responses to meteorological factors in the Altay Mountains, which would be helpful for evaluating and estimating the variation trends of forest ecosystems in China, and has important guiding significance for policy formulation to protect forest resources and improve the local ecological environment.

Influence of Normalization of The Content of Calcium Salts in Body Tissues on The Course of Parkinson's Disease in The Elderly Peapls

Calcium plays an important regulatory and structural role in living organisms. Calcium is a common macronutrient in the body of plants, animals and humans. This chemical element is involved in key physiological and biochemical processes of the cell. Calcium ions are involved in blood coagulation processes, and also serve as one of the universal second messengers inside cells and regulate a variety of intracellular processes - muscle contraction, exocytosis, including the secretion of hormones and neurotransmitters. In the body, calcium is found not only in bones and teeth (about 1 kilogram), but also in the blood. Calcium in the bones is mainly needed for our skeleton to be strong and able to support us. Calcium helps muscles contract, nerves carry messages from the brain to every part of the body, blood vessels move blood throughout the body, release hormones and enzymes that affect almost every function in the body, blood clot, regulate blood pressure and bad cholesterol levels. In old age there is an accumulation in the body of minerals, especially calcium. This is expressed in the deposition of calcium salts in the walls of blood vessels, in joints, cartilage and other tissues. The amount of deposited calcium salts on the tissues of the body, including in the tissues of the brain, is very large, if not enormous. Prior to the start of treatment, all patients were diagnosed by bioresonance. The state of the nosode "Parkinson's disease" ("PD"), organ preparations of the brain - Roof of the midbrain, Red nucleus, Substance nigra, Midbrain, Reticular formation, Lenicular nucleus, Paranigra dopaminergic nucleus were assessed. It was established that in all patients all the listed formations were clearly tested, including the nosode "BP", which indicated the presence of PD. After examining patients with PD using the method of resonance diagnostics, patients begin to use only water with a reduced content of calcium salts in their diet. After 7 weeks of treatment, most of the patients testified that they did not see manifestations of PD in themselves. Their examination showed that the nosode BP and the organ preparations tested before the onset of the disease stopped being tested by the method of resonance diagnostics. The parathyroid gland was also tested in all nine patients (prior to the start of treatment, the parathyroid gland was tested in all patients - it was in a state of degeneration). After 10 weeks of treatment, the rest of the patients reported that they had no manifestations of PD, which was combined with the termination of testing by the method of resonance diagnostics of all previously tested organ preparations, the PD nosode and the parathyroid organ preparation.

Hydraulic failure as a primary driver of xylem network evolution in early vascular plants

The earliest vascular plants had stems with a central cylindrical strand of water-conducting xylem, which rapidly diversified into more complex shapes. This diversification is understood to coincide with increases in plant body size and branching; however, no selection pressure favoring xylem strand-shape complexity is known. We show that incremental changes in xylem network organization that diverge from the cylindrical ancestral form lead to progressively greater drought resistance by reducing the risk of hydraulic failure. As xylem strand complexity increases, independent pathways for embolism spread become fewer and increasingly concentrated in more centrally located conduits, thus limiting the systemic spread of embolism during drought. Selection by drought may thus explain observed trajectories of xylem strand evolution in the fossil record and the diversity of extant forms.

Proteomics of Salt Gland-Secreted Sap Indicates a Pivotal Role for Vesicle Transport and Energy Metabolism in Plant Salt Secretion.

Soil salinization is one of the major factors restricting crop growth and agricultural production worldwide. Recretohalophytes have developed unique epidermal structures in their aboveground tissues, such as salt glands or salt bladders, to secrete excess salt out of the plant body as a protective mechanism from ion damage. Three hypotheses were proposed to explain how salt glands secrete salts: the osmotic hypothesis, a hypothesis similar to animal fluid transport, and vesicle-mediated exocytosis. However, there is no direct evidence to show whether the salt gland-secreted liquid contains landmark proteins or peptides which would elucidate the salt secretion mechanism. In this study, we collected the secreted liquid of salt glands from Limonium bicolor, followed by extraction and identification of its constituent proteins and peptides by SDS-PAGE and mass spectrometry. We detected 214 proteins and 440 polypeptides in the salt gland-secreted droplets of plants grown under control conditions. Unexpectedly, the proportion of energy metabolism-related proteins increased significantly though only 16 proteins and 35 polypeptides in the droplets of salt-treated plants were detected. In addition, vesicle transport proteins such as the Golgi marker enzyme glycosyltransferase were present in the secreted sap of salt glands from both control and salt-treated plants. These results suggest that trans-Golgi network-mediated vesicular transport and energy production contributes to salt secretion in salt glands.

Phytochemical analysis of methanolic extracts of Elymus repens, Typha angustifolia and Caralluma edulis

Introduction: Medicinal plants have been the source of medicine to all civilizations for hundreds of years. In classical medicine, Elymus repens (Poaceae) is consumed as a diuretic, emollient and tonic. It also soothes the pain and spasm in the urinary tract as well as treats the condition of urolithiasis (formation of kidney stones) and urinary tract infections (UTI). In Chinese folk medicine, T. angustifolia is employed to improve the microcirculation, improve body’s defense mechanism, activate contractions of uterus, heal atherosclerosis, treat wounds and promote the differentiation and trigger the division of keratinocytes in humans. The traditional healers recommend C. edulis to cure hypertension, rheumatism, leprosy, diabetes, infections, gastric issues and Alzheimer disease. Objectives: This study was aimed to investigate different phytochemical constituents in methanolic extracts of E. repens (plant body and roots), T. angustifolia (stem and fruiting body) and C. edulis. Methodology: Phytochemical potentials of methanolic extracts of plants were investigated using standard procedures. Results: Phytochemical analysis of E. repens crude methanol extract confirmed the existence of tannins, saponins, flavonoids and anthraquinones. However, phenols were absent in methanol extract of roots. T. angustifolia stem contained anthraquinones. Tannins, saponins, phenols and flavonoids were absent from T. angustifolia stem. C. edulis contains saponins, tannins, flavonoids and anthraquinones except phenols. Conclusion: Results of this study shows that E. repens, T. angustifolia and C. edulis are enriched with different phytochemical constituents hence validating their uses for the treatment of various diseases.

Biology and nature: Bionic superhydrophobic surface and principle.

Nature is the source of human design inspiration. In order to adapt to the environment better, creatures in nature have formed various morphological structures during billions of years of evolution, among which the superhydrophobic characteristics of some animal and plant surface structures have attracted wide attention. At present, the preparation methods of bionic superhydrophobic surface based on the microstructure of animal and plant body surface include vapor deposition, etching modification, sol-gel method, template method, electrostatic spinning method and electrostatic spraying method, etc., which have been used in medical care, military industry, shipping, textile and other fields. Based on nature, this paper expounds the development history of superhydrophobic principle, summarizes the structure and wettability of superhydrophobic surfaces in nature, and introduces the characteristics differences and applications of different superhydrophobic surfaces in detail. Finally, the challenge of bionic superhydrophobic surface is discussed, and the future development direction of this field is prospected.

The size of iron oxide nanoparticles determines their translocation and effects on iron and mineral nutrition of pumpkin (Cucurbita maxima L.)

The ability of nanoparticles (NPs) to migrate in the plant body is an important issue to ensure that the NPs reach the desired tissue and to be able to select the most efficient NPs for agricultural applications. In this study, the size impact of four different iron oxide NPs (8–10, 18–20, 20–40, and 30–50 nm referred as NP10, NP20, NP30, and NP40, respectively) on their translocation in pumpkin was elucidated. To assess the root-to-shoot translocation, phloem sap was examined under transmission electron microscope (TEM). In addition, vibrating sample magnetometer (VSM) and inductively coupled plasma optical emission spectrophotometry (ICP-OES) analyses of stem and leaf tissues were performed to confirm size-dependent translocation. TEM and VSM analyses verified root-to-stem translocation of all tested NPs. The NPs treatment significantly altered the abundances of Mn, Cu, K, P, Al, Mg, and Na in tissues. The iron (Fe) content was abundant in plants treated with NP30 and NP20, and the lowest in plants treated with NP10 and NP40. Together with, only NP30 was found to be significantly translocated to the leaves, where it was 393 mg/kg in DW, about 2.3 times that of control. These findings pointed out the size-dependent translocation of NPs. It seems that biological barriers in the vascular bundle appear to restrict the migration, especially for NPs with an average size of 40 nm and above in pumpkins. These findings are important for selecting the most suitable size of iron oxide NPs for use in agricultural practices.

Spatiotemporal evolutionary and mechanism analysis of grassland GPP in China

At the ecosystem level, Gross Primary Productivity (GPP) was defined as the organic compounds formed by plants that absorb atmospheric CO2 through photosynthesis and sequester carbon in plant bodies. How to accurately assess the spatiotemporal evolution of ecosystem carbon indicators has become a critical issue to be addressed. Chinese grasslands are located in a typical arid and semi-arid climate zone and are sensitive to global changes, which will inevitably have serious impacts on the function and structure of Chinese grasslands. Based on this, our paper takes Chinese grassland ecosystems as the research area, and used multi-source GPP dataset from terrestrial ecosystem model simulations and remote sensing satellite observations to quantitatively analyze the spatiotemporal evolution patterns of GPP in Chinese grasslands over the past 40 years. We combined trend analysis and breakpoint test, and then to analyze the mechanism components of GPP space–time variability. The main results are as follows: (1) The model and remote sensing estimated GPP results showed that more than 80% of Chinese grasslands show a significant increasing trend over the past 40 years, with growth rates ranging from 0.68 to 3.13 g C/m−2 year−1. (2) GPPmax also shows that more than 80% of Chinese grasslands are growing rapidly, with an overall growth rate of more than 0.1 g C/m−2 year−1 in each region. The overall long-term trends and interannual variability of multi-source GPP and GPPmax are generally consistent, yet vegetation dynamics in local areas are still uncertain. (3) The breakpoint test showed that ‘monotonically increasing’ was the largest breakpoint type of GPP in Chinese grasslands (33.09%), and the direction of change of GPP in Chinese grasslands before and after the breakpoint was also increasing. (4) GPPmax × CUP explained 91% of the temporal variability of annual-scale GPP in Chinese grasslands from a mechanistic view, and we found that the peak photosynthetic growth and the length of the phenological period synergistically controlled the interannual variability of GPP in Chinese grasslands. Under the scenario of rapid global change, our study accurately assessed the long-term dynamics of GPP and its mechanism-driven of grassland ecosystems in China, which is helpful for estimating and predicting the carbon budget of grassland ecosystems in China, and has important guiding significance for policy formulation to mitigate climate change.

Effective removal of chromium from aqueous solution by adsorption on powdered wool: In-silico studies of adsorption mechanism

• Molecular docking gives mechanism of adsorption of Cr(VI) on powdered wool. • Adsorption of Cr(VI) on powdered takes place at low pH and desorption at high pH. • Most of Cr(VI) is adsorbed on powdered wool within 30 s. • The process of adsorption is spontaneous and exothermic. • The Langmuir adsorption capacity of powdered wool for Cr(VI) is 23 mg/g. Industrial wastewater contains a significant quantity of Chromium (VI) which is greatly mobile in water and soil. It is genotoxic, carcinogenic and accumulates in plant and animal bodies. Current work reports the chromium removal by adsorption on powdered wool. Wool was powdered mechanically to 90–120 mesh size. Powdered wool before and after chromium adsorption was characterized using FTIR, BET, EDX, XRD, TGA, and FE-SEM. Powdered wool (175 mg) removed 99.43% of Cr(VI) from the solution at pH 2.1 on shaking for 3.5 min at 20 °C. Observed Langmuir adsorption capacity on powdered wool for Cr(VI) was 23 mg at 20 °C. Used powdered wool was regenerated by washing with pH 12.6 buffer solutions and reused without much decrease in its adsorption capacity up to three cycles (91.0% removal). Cr(VI) binding mechanism with powdered wool protein was studied using molecular docking and observed predominant interacting forces were hydrogen bonding and Van-der-Waals forces revealed.

A Short History of Plant Light Microscopy.

When the microscope was first introduced to scientists in the 17th century, it started a revolution. Suddenly, a whole new world, invisible to the naked eye, was opened to curious explorers. In response to this realization, Nehemiah Grew, an English plant anatomist and physiologist and one of the early microscopists, noted in 1682 "that Nothing hereof remains further to be known, is a Thought not well Calculated". Since Grew made his observations, the microscope has undergone numerous variations, developing from early compound microscopes-hollow metal tubes with a lens on each end-to the modern, sophisticated, out-of-the-box super-resolution microscopes available to researchers today. In this Overview article, I describe these developments and discuss how each new and improved variant of the microscope led to major breakthroughs in the life sciences, with a focus on the plant field. These advances start with Grew's simple and-at the time-surprising realization that plant cells are as complex as animals cells, and that the different parts of the plant body indeed qualify to be called "organs", then move on to the development of the groundbreaking "cell theory" in the mid-19th century and the description of eu- and heterochromatin in the early 20th century, and finish with the precise localization of individual proteins in intact, living cells that we can perform today. Indeed, Grew was right; with ever-increasing resolution, there really does not seem to be an end to what can be explored with a microscope. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC.

Laticifer growth pattern is guided by cytoskeleton organization.

Laticifers are secretory structures that produce latex, forming a specialized defense system against herbivory. Studies using anatomical approaches to investigate laticifer growth patterns have described their origin; however, their mode of growth, i.e., whether growth is intrusive or diffuse, remains unclear. Studies investigating how cytoskeleton filaments may influence laticifer shape establishment and growth patterns are lacking. In this study, we combined microtubule immunostaining and developmental anatomy to investigate the growth patterns in different types of laticifers. Standard anatomical methods were used to study laticifer development. Microtubules were labelled through immunolocalization of α-tubulin in three types of laticifers from three different plant species: nonanastomosing (Urvillea ulmacea), anastomosing unbranched with partial degradation of terminal cell walls (Ipomoea nil), and anastomosing branched laticifers with early and complete degradation of terminal cell walls (Asclepias curassavica). In both nonanastomosing and anastomosing laticifers, as well as in differentiating meristematic cells, parenchyma cells and idioblasts, microtubules were perpendicularly aligned to the cell growth axis. The analyses of laticifer microtubule orientation revealed an arrangement that corresponds to those cells that grow diffusely within the plant body. Nonanastomosing and anastomosing laticifers, branched or not, have a pattern which indicates diffuse growth. This innovative study on secretory structures represents a major advance in the knowledge of laticifers and their growth mode.

Effect of Nickel Ions on the Physiological and Transcriptional Responses to Carbon and Nitrogen Metabolism in Tomato Roots under Low Nitrogen Levels.

Nickel (Ni) is an essential trace element for plant growth and a component of the plant body that has many different functions in plants. Although it has been confirmed that nickel ions (Ni2+) havea certain regulatory effect on nitrogen (N) metabolism, there are not enough data to prove whether exogenous Ni2+ can increase the carbon (C) and N metabolism in the roots of tomato seedlingsunder low-nitrogen (LN) conditions. Therefore, through the present experiment, we revealed the key mechanism of Ni2+-mediated tomato root tolerance to LN levels. Tomato plants were cultured at two different N levels (7.66 and 0.383 mmol L−1) and two different Ni2+ levels (0 and 0.1 mg L−1 NiSO4 6H2O) under hydroponic conditions. After nine days, we collected roots for physiological, biochemical, and transcriptome sequencing analyses and found that the activities of N assimilation-related enzymes decreased at LN levels. In contrast, Ni2+ significantly increased the activities of N assimilation-related enzymes and increased the contents of nitrate (NO3−), ammonium (NH4+), and total amino acids. Through root transcriptomic analysis, 3738 differentially expressed genes (DEGs) were identified. DEGs related to C and N metabolism were downregulated after LN application. However, after Ni2+ treatment, PK, PDHB, GAPDH, NR, NiR, GS, GOGAT, and other DEGs related to C and N metabolism were significantly upregulated. In conclusion, our results suggest that Ni2+ can regulate the C and N metabolism pathways in tomato roots to alleviate the impact of LN levels.

Unravelling the Efficient Applications of Zinc and Selenium for Mitigation of Abiotic Stresses in Plants

Abiotic stress factors are considered a serious threat to various growth parameters of crop plants. Stressors such as drought, salinity, and heavy metals (HMs) hamper the chlorophyll content in plants, resulting in low photosynthesis, hinder the integrity of cell membranes, reduce biomass, and overall growth and development of crops which ultimately results in the sharp decline of crop yield. Under such stressful conditions, various strategies are employed to overcome hazardous effects. Application of Zinc (Zn) or Selenium (Se) in different forms is an effective way to alleviate the abiotic stresses in plants. Zn and Se play a pivotal role in enhancing the chlorophyll level to improve photosynthesis, reducing oxidative stress by limiting reactive oxygen species (ROS) production, controlling HMs absorption by plant roots and their accumulation in the plant body, maintaining homeostasis, and alleviating all the detrimental effects caused by abiotic stress factors. The current review is focused on the usefulness of Zn and Se application, their uptake, sensitization, and different defence mechanisms to relieve adverse effects of abiotic stresses (such as drought, salinity, and HMs) on crops. In this connection, research gaps have also been highlighted.

Effect of neighbourhood courtyard design on the outdoor thermal comfort in a tropical city

In the tropical city of Ha Tinh (Vietnam), the number of new developed neighbourhoods in the courtyard layout is increasing while the city is experiencing annual severe heat stress. The paper quantitatively analyses, by means of ENVI-Met simulation, the effect of neighbourhood courtyard landscape on the outdoor thermal comfort (OTC) in the tropical city of Ha Tinh (Vietnam). A sample 9-ha residential block was at first experimentally configured with four scenarios of courtyard, including (1) bare grass and perimetry location of high plants, (2) grass ground, fully occupied high trees, (3) water body and perimetry location of high plants, and (4) mixed ground surfaces of water, hard pavement and grass, and partly occupied high trees. The adding of tree canopies to the entire courtyard, consequently sufficient shades, as in case 2, contributes to the better OTC among the chosen scenarios by triggering the reduction of mean radiant temperature (Tmrt) (2.9°C) and physiological equivalent temperature (PET) (3.5°C) at the hottest hours as compared to the original configuration (case 1) during the summer days. Application of perimetry plants with either water (case 1) or bare grass (case 3) results in higher PET though full occupation of water body lowers the air temperature by roughly 1°C. The limited impact on OTC of local water body is counter-intuitive, yet important result to the practice of urban design. The worst OTC was observed in case 4 where almost half of the garden was sun-exposed and intended for hard-paved playground and water body. Increasing shades against solar radiation is the most important measure to deal with intensive heat problem. The study is an essential part of translating academic knowledge on urban climate into interventions on urban design for better climate resilience of neighbourhoods in Vietnam and by extend in other tropical countries.