scholarly journals Rootstock-Dependent Response of Hass Avocado to Salt Stress

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1672
Author(s):  
Silit Lazare ◽  
Yafit Cohen ◽  
Eitan Goldshtein ◽  
Uri Yermiyahu ◽  
Alon Ben-Gal ◽  
...  

Salt stress is a major limiting factor in avocado (Persea americana) cultivation, exacerbated by global trends towards scarcity of high-quality water for irrigation. Israeli avocado orchards have been irrigated with relatively high-salinity recycled municipal wastewater for over three decades, over which time rootstocks were selected for salt-tolerance. This study’s objective was to evaluate the physiological salt response of avocado as a function of the rootstock. We irrigated fruit-bearing ‘Hass’ trees grafted on 20 different local and introduced rootstocks with water high in salts (electrical conductivity of 1.4–1.5 dS/m). The selected rootstocks represent a wide range of genetic backgrounds, propagation methods, and horticultural characteristics. We investigated tree physiology and development during two years of salt exposure by measuring Cl and Na leaf concentrations, leaf osmolality, visible damages, trunk circumference, LAI, CO2 assimilation, stomatal conductance, spectral reflectance, stem water potential, trichomes density, and yield. We found a significant effect of the rootstocks on stress indicators, vegetative and reproductive development, leaf morphogenesis and photosynthesis rates. The most salt-sensitive rootstocks were VC 840, Dusa, and VC 802, while the least sensitive were VC 159, VC 140, and VC 152. We conclude that the rootstock strongly influences avocado tree response to salinity exposure in terms of physiology, anatomy, and development.

2003 ◽  
Vol 3 (5-6) ◽  
pp. 321-327 ◽  
Author(s):  
M. Gallenkemper ◽  
T. Wintgens ◽  
T. Melin

Endocrine disrupting compounds can affect the hormone system in organisms. A wide range of endocrine disrupters were found in sewage and effluents of municipal wastewater treatment plants. Toxicological evaluations indicate that conventional wastewater treatment plants are not able to remove these substances sufficiently before disposing effluent into the environment. Membrane technology, which is proving to be an effective barrier to these substances, is the subject of this research. Nanofiltration provides high quality permeates in water and wastewater treatment. Eleven different nanofiltration membranes were tested in the laboratory set-up. The observed retention for nonylphenol (NP) and bisphenol A (BPA) ranged between 70% and 100%. The contact angle is an indicator for the hydrophobicity of a membrane, whose influence on the permeability and retention of NP was evident. The retention of BPA was found to be inversely proportional to the membrane permeability.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 845
Author(s):  
Helena Hnilickova ◽  
Kamil Kraus ◽  
Pavla Vachova ◽  
Frantisek Hnilicka

In this investigation, the effect of salt stress on Portulaca oleracea L. was monitored at salinity levels of 100 and 300 mM NaCl. At a concentration of 100 mM NaCl there was a decrease in stomatal conductance (gs) simultaneously with an increase in CO2 assimilation (A) at the beginning of salt exposure (day 3). However, the leaf water potential (ψw), the substomatal concentration of CO2 (Ci), the maximum quantum yield of photosystem II (Fv/Fm), and the proline and malondialdehyde (MDA) content remained unchanged. Exposure to 300 mM NaCl caused a decrease in gs from day 3 and a decrease in water potential, CO2 assimilation, and Fv/Fm from day 9. There was a large increase in proline content and a significantly higher MDA concentration on days 6 and 9 of salt stress compared to the control group. After 22 days of exposure to 300 mM NaCl, there was a transition from the C4 cycle to crassulacean acid metabolism (CAM), manifested by a rapid increase in substomatal CO2 concentration and negative CO2 assimilation values. These results document the tolerance of P. oleracea to a lower level of salt stress and the possibility of its use in saline localities.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
L. Osipova ◽  
O. Radionova ◽  
L. Tkachenko ◽  
T. Abramova

The analysis of the current state of processing of secondary raw materials of wine-making in Ukraine is given. It is proved that the latter is a rich source of biologically active compounds, including phenolic ones, which makes it possible to use it for the production of a wide range of products (raccoon, polyphenol extracts, tartaric acid, beverages, fertilizers, grape oil, cake, vitamin D, animal feed, food powder, abrasives) with high consumer value for various industries: food, pharmaceutical, perfume and cosmetics, chemical, feed, etc. In the light of modern research, the role of phenolic compounds as essential nutrition factors that cannot remain out of the field of view of physiologists, pharmacologists, and food hygiene specialists is shown. However, currently in Ukraine there are no specialized enterprises for complex processing of secondary raw materials of winemaking; traditional technologies are not effective from a technological, economic and environmental point of view, which indicates not rational use of resources and loss of material resources; there are no systematic studies on physical and chemical, microbiological, Toxicological composition in order to determine the optimal direction of its use. A limiting factor is also the lack of comparative analysis of innovative domestic and foreign technologies for processing secondary raw materials of winemaking. In the vast majority of cases, in particular, combs and pomace are taken out of control to agricultural land without special treatment, which leads to acid soil erosion and pollution of the environment with metabolites of micromycetes, increasing one of the global problems of mankind-environmental. At the present stage of technological development, there are a number of innovative developments in the field of processing secondary raw materials, in particular grape pomace, in order to obtain biologically active additives, the limiting factor for the introduction of which is the lack of domestic and expensive imported equipment. A promising way to solve the existing problems is to create a mechanism that will unite the interests of wineries (producers of secondary raw materials of winemaking), processing enterprises (producers of products from secondary raw materials of winemaking), scientists and potential consumers of innovative products. Consolidation of the above-mentioned institutions and enterprises is possible by creating clusters for the development and implementation of innovative technologies and equipment


2021 ◽  
Vol 29 (2) ◽  
pp. 324-337
Author(s):  
Elena S. Pinchuk

The article reviews the trends in the media industry landscape formation based on content as a source of economic processes taking place in the industry. A wide range of expert opinions, reflecting the current changes was collected and analyzed. The life cycle of content is examined and the key trends in its production, packaging, distribution and consumption are highlighted. The attention is focused on the economic and technological factors that determine each of the trends, for instance, a change in the model of media consumption, the development and distribution of OTT platforms as a new way of delivering content, as well as a rapid transition to a new technological level. The latest statistical data from Russian and foreign sources support the reviewed trends. There is a separate description of the coronavirus pandemic impact consequences on the global media and the Russian industry in particular, and the key aspects of the development of the industry are identified in the current period on its basis.


2004 ◽  
Vol 129 (2) ◽  
pp. 188-192 ◽  
Author(s):  
N. Bernstein ◽  
A. Meiri ◽  
M. Zilberstaine

In most crop species, growth of the shoot is more sensitive to salt stress than root growth. Avocado [Persea americana Mill.] is very sensitive to NaCl stress. Even low concentrations of salt (15 mm) inhibit tree growth and decrease productivity. Observations in experimental orchards have suggested that root growth in avocado might be more restricted by salinity than shoot growth. In the present study, we evaluated quantitatively the inhibitory effects of salt stress on growth of the avocado root in comparison to the shoot. Seedling plants of the West-Indian rootstock `Degania 117' were grown in complete nutrient solution containing 1, 5, 15, or 25 mm NaCl. The threshold NaCl concentration causing root and shoot growth reduction occurred between 5 and 15 mm. At all concentrations, root growth was much more sensitive to salinity than shoot growth. A concentration of 15 mm NaCl, which did not affect the rate of leaf emergence on the plant and decreased leaf biomass production only 10%, induced a 43% reduction in the rate of root elongation and decreased root volumetric growth rate by 33%. Under 25 mm NaCl, leaf biomass production, leaf initiation rate and leaf elongation rate were reduced 19.5%, 12%, and 5%, respectively, while root volumetric growth and root elongation rate were reduced 65% and 75%, respectively. This strong root growth inhibition is expected to influence the whole plant and therefore root growth under salinity should be considered as an important criterion for rootstocks' tolerance to NaCl.


Author(s):  
G. W. Bryan

The relationship between the ability of brackish water invertebrates to regulate Na and K and the extent to which the radioactive fission product 137Cs can be accumulated has been studied.The brackish water isopod Sphaeroma hookeri and the gastropod Potamopyrgus jenkinsi have been acclimatised to a wide range of sea-water dilutions. Unfed Sphaeroma can survive in sea-water concentrations of 100–2·5%, while Potamopyrgus can live fairly indefinitely in concentrations of 50–0·1%. Measurements of Na and K in the whole animals of both species and in the blood of Sphaeroma have been made. Salt movements are quite rapid and acclimatization to new media is achieved by both species in less than 10 h. Concentration factors for inactive K in particular increase to high values in the more dilute media.Uptake of the isotopes 42K and 137Cs from solution has been examined in both species over a range of sea-water concentrations. All of the body K is exchangeable with 42K and in Sphaeroma exchange of 42K between the blood and tissues is so rapid that the body surface appears to be the limiting factor in the uptake of the isotope. Both species exchange 42K more rapidly in the higher concentrations of sea water and one reason for this may be the existence of an exchange diffusion component of exchange which increases as the salinity of the medium is raised. Indirect evidence suggests that the excretion of 42K in urine is probably not an important factor in exchange.


Weed Science ◽  
2021 ◽  
pp. 1-27
Author(s):  
Aseemjot Singh ◽  
Gulshan Mahajan ◽  
Bhagirath Singh Chauhan

Abstract Wild mustard (Sinapis arvensis L.) is a widespread weed of the southeastern cropping region of Australia. Seed germination ecology of S. arvensis populations selected from different climatic regions may differ due to adaptative traits. Experiments were conducted to evaluate the effects of temperature, light, radiant heat, soil moisture, salt concentration, and burial depth on seed germination and seedling emergence of two [Queensland (Qld) population: tropical region; and Victoria (Vic) population: temperate region] populations of S. arvensis. Both populations germinated over a wide range of day/night (12 h/12 h) temperatures (15/5 to 35/25 C), and had the highest germination at 30/20 C. Under complete darkness, the Qld population (61%) had higher germination than the Vic population (21%); however, under the light/dark regime, both populations had similar germination (78 to 86%). At 100 C pretreatment for 5 min, the Qld population (44%) had higher germination than the Vic population (13%). Germination of both populations was nil when given pretreatment at 150 and 200 C. The Vic population was found tolerant to high osmotic and salt stress compared with the Qld population. At an osmotic potential of −0.4 MPa, germination of Qld and Vic populations was reduced by 85% and 42%, respectively, compared with their respective control. At 40, 80, and 160 mM sodium chloride, germination of the Qld population was lower than the Vic population. Averaged over the populations, seedling emergence was highest (52%) from a burial depth of 1 cm and was nil from 8 cm depth. Differential germination behaviors of both populations to temperature, light, radiant heat, water stress, and salt stress suggests that populations of S. arvensis may have undergone differential adaptation. Knowledge gained from this study will assist in developing suitable control measures for this weed species to reduce the soil seedbank.


Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 560 ◽  
Author(s):  
Muhammad Shehzad ◽  
Zhongli Zhou ◽  
Allah Ditta ◽  
Xiaoyan Cai ◽  
Majid Khan ◽  
...  

Abiotic stress is an important limiting factor in crop growth and yield around the world. Owing to the continued genetic erosion of the upland cotton germplasm due to intense selection and inbreeding, attention has shifted towards wild cotton progenitors which offer unique traits that can be introgressed into the cultivated cotton to improve their genetic performance. The purpose of this study was to characterize the Pkinase gene family in a previously developed genetic map of the F2 population derived from a cross between two cotton species: Gossypium hirsutum (CCRI 12-4) and Gossypium darwinii (5-7). Based on phylogenetic analysis, Pkinase (PF00069) was found to be the dominant domain with 151 genes in three cotton species, categorized into 13 subfamilies. Structure analysis of G. hirsutum genes showed that a greater percentage of genes and their exons were highly conserved within the group. Syntenic analysis of gene blocks revealed 99 duplicated genes among G. hirsutum, Gossypium arboreum and Gossypium raimondii. Most of the genes were duplicated in segmental pattern. Expression pattern analysis showed that the Pkinase gene family possessed species-level variation in induction to salinity and G. darwinii had higher expression levels as compared to G. hirsutum. Based on RNA sequence analysis and preliminary RT-qPCR verification, we hypothesized that the Pkinase gene family, regulated by transcription factors (TFs) and miRNAs, might play key roles in salt stress tolerance. These findings inferred comprehensive information on possible structure and function of Pkinase gene family in cotton under salt stress.


2020 ◽  
Vol 21 (18) ◽  
pp. 6616
Author(s):  
Yuliya Kloc ◽  
Marta Dmochowska-Boguta ◽  
Andrzej Zielezinski ◽  
Anna Nadolska-Orczyk ◽  
Wojciech M. Karlowski ◽  
...  

Glycogen synthase kinase 3 (GSK3) is a highly conserved kinase present in all eukaryotes and functions as a key regulator of a wide range of physiological and developmental processes. The kinase, known in land plants as GSK3/SHAGGY-like kinase (GSK), is a key player in the brassinosteroid (BR) signaling pathway. The GSK genes, through the BRs, affect diverse developmental processes and modulate responses to environmental factors. In this work, we describe functional analysis of HvGSK1.1, which is one of the GSK3/SHAGGY-like orthologs in barley. The RNAi-mediated silencing of the target HvGSK1.1 gene was associated with modified expression of its paralogs HvGSK1.2, HvGSK2.1, HvGSK3.1, and HvGSK4.1 in plants grown in normal and in salt stress conditions. Low nucleotide similarity between the silencing fragment and barley GSK genes and the presence of BR-dependent transcription factors’ binding sites in promoter regions of barley and rice GSK genes imply an innate mechanism responsible for co-regulation of the genes. The results of the leaf inclination assay indicated that silencing of HvGSK1.1 and the changes of GSK paralogs enhanced the BR-dependent signaling in the plants. The strongest phenotype of transgenic lines with downregulated HvGSK1.1 and GSK paralogs had greater biomass of the seedlings grown in normal conditions and salt stress as well as elevated kernel weight of plants grown in normal conditions. Both traits showed a strong negative correlation with the transcript level of the target gene and the paralogs. The characteristics of barley lines with silenced expression of HvGSK1.1 are compatible with the expected phenotypes of plants with enhanced BR signaling. The results show that manipulation of the GSK-encoding genes provides data to explore their biological functions and confirm it as a feasible strategy to generate plants with improved agricultural traits.


Ozone Therapy ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Giuseppe Vitali ◽  
Luigi Valdenassi

Ozone (O3) is a bluish-coloured gas with a characteristic odour that forms in the layers of the atmosphere, near electric shocks, sparks or lightning; the extremely high voltages reached during thunderstorms produce ozone from oxygen. The particular fresh, clean odour, the smell of spring rain is the result of the ozone reproduced by nature. Ozone comes from the Greek word ozein, which means to sense the odour of. Ozone is an essential gas for life on Earth, allowing the absorption of ultraviolet light emanating from the Sun; in fact, the ozone layer in the stratosphere protects against the harmful action of UV-B ultraviolet rays. The gas, not being stable over the long term, is therefore not produced in cylinders; it can currently be prepared through special, certified and authorised devices, which use small electric discharges to convert the oxygen into ozone. It is a molecule formed by three oxygen atoms (O3), with a negative electric charge. It has a short half-life, and will therefore decay after a certain time back to its original form: oxygen. Essentially ozone is nothing but oxygen (O2) with an extra oxygen atom, which has a high electrical charge. Ozone works according to the principle of oxidation. The oxidation mechanism follows two paths: i) Direct: contact of the molecule with the contaminant; ii) Indirect: the ozone decomposes into hydroxyl radicals, more powerful but short-lived. Both reactions occur simultaneously. When the static charged ozone molecule (O3) comes into contact with something capable of oxidising, the ozone molecule’s charge flows directly over it. This happens because ozone is very unstable and tends to change back into its original form (O2). Ozone can oxidise with all kinds of materials, but also with odours and microorganisms such as bacteria, viruses and fungi. The supplemental oxygen atom is released from the ozone molecule and binds to the other material. In the end, only the pure and stable oxygen molecule remains. Ozone is one of the strongest oxidation techniques available for oxidising solutes. The supplemental/added oxygen atom will bind (=oxidation) in a second to each component that comes into contact with ozone. It is used for a wide range of purification processes. It can be employed for disinfection in municipal wastewater and in drinking water treatment plants. However, ozone is increasingly used in the industrial sector. In the food industry, for example, it is used for disinfection, and in the textile and paper industry it is used to oxidise wastewater. The main benefit of ozone is its clean nature, because it only oxidises the materials, barely forming any by-products. Since ozone has a strong characteristic distinctive odour, even very low concentrations can be quickly perceived. This generally makes it safe to work with. Since Chlorine is still the best-known oxidising and disinfectant agent, ozone is often compared with chlorine. Unlike chlorine, antibiotics or various chlorine derivatives that have no effect, ozone acts on viruses and spores. In its sterilising action, ozone directly attacks bacteria by inducing a catalytic oxidation process on the mass of bacterial proteins, unlike chlorine which acts only through specific enzymatic poisoning of vital centres, a process which requires a longer time interval and sensitive quantity for its diffusion inside the cytoplasm. Regarding the virucidal action, it is interesting to keep in mind that with a residual ozone rate of 0.6 ppm (parts per million) and with a contact time of 2 minutes, the percentage of inactivation for bacteria and viruses present in the disinfection liquid is total. Ozone’s oxidising power is 120 times greater than that of chlorine.


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