Salinity tolerance in Spergularia marina

1985 ◽  
Vol 63 (10) ◽  
pp. 1762-1768 ◽  
Author(s):  
John M. Cheeseman ◽  
P. Bloebaum ◽  
Carol Enkoji ◽  
Linda K. Wickens
Keyword(s):  
Fresh Water ◽  
Higher Plants ◽  
Specific Effect ◽  
Distribution Patterns ◽  
Growth Stimulation ◽  
Solution Culture ◽  
Ion Content ◽  
Physiological Basis ◽  
Leaf Surface Area ◽  
Spergularia Marina

Attributes of the coastal halophyte Spergularia marina (L.) Griseb. that make it useful for studies of the physiological basis for salt tolerance in fully autotrophic higher plants are discussed. Growth, morphological, and ion-content characteristics are presented to serve as a background for subsequent studies of transport physiology. Plants were grown in solution culture on dilutions of artificial seawater or on the same solution without NaCl ("fresh water") from the time at which they could be conveniently transferred as seedlings (about 2 weeks old) to the onset of flowering about 5 weeks later. Eighteen days after transfer, plants growing on 0.2 × seawater were larger, being nearly twice the size of plants on fresh water. A Na+ specific effect was indicated, as the major part of the growth stimulation (54%) resulted from a 1 mM NaCl supplementation of "fresh water." Succulence was not a consideration in the growth response: root length was directly proportional to weight as was leaf surface area and neither was affected by salinity. Total Na+ plus K+ per gram root or shoot showed little variation with salinity from 1 to 180 mM Na+ levels. In roots, the relative Na+ and K+ contents were also little affected by salinity, but in the shoots, increasing salinity resulted in higher Na+ and lower K+ contents. Distribution within the shoots of 0.2 × plants showed no regions either free of or exceptionally high in Na+. The ion content and distribution patterns are compared with those in a number of other halophytes.

scholarly journals Leaf Trichome Distribution Pattern in Arabidopsis Reveals Gene Expression Variation Associated with Environmental Adaptation

Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 909
Author(s):  
Shotaro Okamoto ◽  
Kohei Negishi ◽  
Yuko Toyama ◽  
Takeo Ushijima ◽  
Kengo Morohashi
Keyword(s):  
Gene Expression ◽  
Distribution Pattern ◽  
Higher Plants ◽  
Reaction Diffusion ◽  
Distribution Patterns ◽  
Environmental Adaptation ◽  
Stochastic Variation ◽  
Biological Relevance ◽  
Homogeneous Cell ◽  
Multicellular Organisms

Gene expression varies stochastically even in both heterogenous and homogeneous cell populations. This variation is not simply useless noise; rather, it is important for many biological processes. Unicellular organisms or cultured cell lines are useful for analyzing the variation in gene expression between cells; however, owing to technical challenges, the biological relevance of this variation in multicellular organisms such as higher plants remain unclear. Here, we addressed the biological relevance of this variation between cells by examining the genetic basis of trichome distribution patterns in Arabidopsis thaliana. The distribution pattern of a trichome on a leaf is stochastic and can be mathematically represented using Turing’s reaction-diffusion (RD) model. We analyzed simulations based on the RD model and found that the variability in the trichome distribution pattern increased with the increase in stochastic variation in a particular gene expression. Moreover, differences in heat-dependent variability of the trichome distribution pattern between the accessions showed a strong correlation with environmental factors to which each accession was adapted. Taken together, we successfully visualized variations in gene expression by quantifying the variability in the Arabidopsis trichome distribution pattern. Thus, our data provide evidence for the biological importance of variations in gene expression for environmental adaptation.

Mineral Cycling and Lichens: The Physiological Basis

1991 ◽  
Vol 23 (3) ◽  
pp. 293-307 ◽  
Author(s):  
Dennis H. Brown ◽  
Rosalie M. Brown
Keyword(s):  
Toxic Metal ◽  
Distribution Patterns ◽  
Essential Elements ◽  
Mineral Matter ◽  
Physiological Basis ◽  
Wet And Dry Deposition ◽  
Mineral Cycling ◽  
Physiological Processes ◽  
Field And Laboratory Conditions

AbstractA number of physiological processes relevant to the role of lichens in mineral cycling are discussed. Consideration is given to the cellular location of positively-charged cations, showing (a) the benefits of quantifying intracellular elements for the interpretation of toxic metal stress, and (b) how distribution patterns of physiologically essential elements may be altered by desiccation and rehydration under field and laboratory conditions. The quantitative significance of these dynamic processes associated with metal uptake and loss requires verification under field conditions. A modified sequential elution procedure is proposed that enables quantification of insoluble paniculate mineral matter (acquired by wet and dry deposition) in addition to soluble elements in intercellular, extracellular-exchangeable and intracellular sites.

Characterization of manganese use efficiency in UK wheat cultivars grown in a solution culture system and in the field

2005 ◽  
Vol 143 (2-3) ◽  
pp. 151-160 ◽  
Author(s):  
W. Z. JIANG ◽  
C. R. IRELAND
Keyword(s):  
Spring Wheat ◽  
Crop Improvement ◽  
Dry Weight ◽  
Solution Culture ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Apparent Quantum Yield ◽  
Physiological Basis ◽  
Use Efficiency ◽  
Wheat Lines

The aim of the research was to describe and characterize the physiological basis of Mn use efficiency among a range of old and modern UK wheat cultivars grown in Mn-depleted solution culture and to ascertain whether the existence of Mn use efficiency conferred a yield advantage under manganese stress conditions in the field. Results of solution culture experiments demonstrated that the old spring wheat cv. Maris Butler is relatively Mn efficient when grown in Mn-deficient conditions in comparison with both a modern winter wheat, cv. Claire, and a modern spring wheat, cv. Paragon. The mean dry weight gain of plants of cv. Maris Butler grown in Mn-depleted nutrient solution was 0·49 of that shown by plants in Mn-sufficient culture, whereas in cvs. Paragon and Claire the equivalent values were 0·38 and 0·21 respectively. When grown in Mn-deficient soil in a farm-based field trial, cv. Maris Butler showed significantly improved (P<0·05) dry matter accumulation and grain yield compared with other spring wheats including cv. Paragon. There was no significant variation in leaf Mn content between the cultivars examined, either under sufficient or depleted Mn supply; however, cv. Maris Butler showed both a relatively high maximum light-saturated rate of photosynthesis and a high photosynthetic apparent quantum yield (based on O2 evolution) when grown under Mn deficiency. It is argued that the apparent Mn use efficiency of cv. Maris Butler is related to superior internal utilization of Mn, resulting in an increased photosynthetic photosytem II efficiency rather than improved Mn uptake and accumulation. The results suggest that the wheat cultivar Maris Butler may provide a potentially useful source of parental material for future crop improvement programmes designed to produce wheat lines resistant to depleted Mn supply.

scholarly journals Induction of orientation of bacterial cellulose microfibrils by a novel terpenoid from Acetobacter xylinum

1973 ◽  
Vol 135 (1) ◽  
pp. 145-149 ◽  
Author(s):  
W. Geoffrey Haigh ◽  
Hans J. Förster ◽  
Klaus Biemann ◽  
Neil H. Tattrie ◽  
J. Ross Colvin
Keyword(s):  
Higher Plants ◽  
Specific Effect ◽  
Ring System ◽  
Acetobacter Xylinum ◽  
Cellulose Microfibrils ◽  
Common Mechanism ◽  
Bacterial Cells ◽  
Total Lipids ◽  
Crude Lipid ◽  
Saponifiable Fraction

1. The bacterium Acetobacter xylinum produces extracellular cellulose microfibrils that form a pellicle in the medium enmeshing the bacterial cells. These microfibrils may show some localized alignment, which can be seen as birefringence when the culture is viewed between crossed Polaroid sheets. 2. An increase in birefringence can be induced by the addition of small amounts of certain classes of lipids, particularly sterols, to the cultures. 3. A crude lipid extract from Acetobacter cells induced greatly increased birefringence when added to fresh cultures of this organism. 4. When the bacterial lipids were fractionated, most of the activity was recovered in a complex, polar lipid. The lipid is secreted into the medium during growth and is unstable. The non-saponifiable portion of this lipid is shown to be a 1:1 mixture of a saturated and a monounsaturated C35 tetrahydroxy terpene with a hopane ring system in the accompanying paper by Förster et al. (1973). The saturated molecule is referred to as tetrahydroxybacteriohopane. 5. Tetrahydroxybacteriohopane is itself capable of inducing birefringence in cultures as is 22-hydroxyhopane, which was also isolated from the non-saponifiable fraction of the total lipids. 6. The mechanism of induction of birefringence (orientation of microfibrils) is not known. This is unlikely to be a specific effect, since all the above compounds are active (intact lipid, tetrahydroxybacteriohopane, 22-hydroxyhopane), as are other classes of lipid. It is suggested, however, that a common mechanism may be involved and that similar compounds may be concerned with control of microfibril alignment in the cells of higher plants.

Some biological effects of volatiles emanating from wood

1970 ◽  
Vol 48 (4) ◽  
pp. 719-735 ◽  
Author(s):  
P. F. Rice
Keyword(s):  
Higher Plants ◽  
Biological Effects ◽  
Nutrient Status ◽  
Growth Stimulation ◽  
Test Organisms ◽  
Growth Promoting ◽  
Dose Levels ◽  
Fixed Period ◽  
Fungus Growth

Early in vitro observations on the biological activity of volatiles from heat-dried woods indicated two major properties: one of retarding growth of higher plants and another of stimulating growth of a wood-inhabiting Basidiomycete. For the purpose of determining the chemical nature of the active volatiles and their parent sources principally in red pine wood (Pinus resinosa), these two properties were investigated separately with the aid of bioassay techniques. Two test organisms were used: germinated kidney beans (Phaseolus vulgaris) and the fungus Fomes annosus. Various dose levels of volatile sources were suspended over the test organisms for a fixed period of time, after which growth was measured.Experimental evidence indicated that bean growth inhibition and fungus growth stimulation could be attributed to volatile autoxidation products derived from certain unsaturated fatty components of wood. In particular, linoleic acid appeared to be a major phytoactive source. A number of aliphatic aldehydes, reported in the literature as fat autoxidation products, were found to be phytotoxic to beans in appropriate quantities, but none had any growth promoting properties on the fungus. Also, indications were that fungus response to wood volatiles was largely independent of the nutrient status of the substrate, provided a suitable nutrient complement was present. It was proposed that yet unidentified non-aldehydic substances, or specific untested aldehydes, functioned as the growth factors.

Gastropod communities associated with different morphologies of the intertidal seaweed Hormosira banksii

2019 ◽  
Vol 70 (2) ◽  
pp. 280 ◽  
Author(s):  
F. Gemelli ◽  
C. R. Johnson ◽  
J. T. Wright
Keyword(s):  
Morphological Traits ◽  
Specific Effect ◽  
Distribution Patterns ◽  
North Coast ◽  
Physical Conditions ◽  
The North ◽  
Intertidal Seaweed ◽  
Abundance And Diversity ◽  
The Relationship ◽  
Thallus Length

Hormosira banksii is an important intertidal habitat-forming seaweed in southern Australia that shows large variation in morphology. We examined the relationship between morphological variation in Hormosira and associated gastropod community structure, abundance and diversity in Tasmania, southern Australia. We sampled both Hormosira and gastropods from sites in two habitats (coast and estuary), two times (February–March and October–November) at two regions (northern and eastern Tasmania). There were distinct Hormosira morphs on the north coast (small individuals), east coast (intermediate sized individuals) and in estuaries (large individuals). Multivariate analysis showed that gastropod communities varied among the different algal morphologies, and suggest an influence of morphological traits, specifically thallus length, vesicle number and size, on the distribution patterns of gastropod species. Despite the finding of distinct gastropod communities associated with the different Hormosira morphs, because the different morphs occur in different locations with different physical conditions, we cannot unequivocally attribute the differences in gastropod communities to seaweed morphology per se. Nonetheless, our results confirm that H. banksii is an important foundation species in the intertidal zone and suggest a habitat-specific effect of algal morphological traits on gastropods.

Tolerance of aluminium toxicity in annual Medicago species and lucerne

2008 ◽  
Vol 48 (4) ◽  
pp. 499 ◽  
Author(s):  
B. J. Scott ◽  
M. A. Ewing ◽  
R. Williams ◽  
A. W. Humphries ◽  
N. E. Coombes
Keyword(s):  
Average Length ◽  
Aluminium Toxicity ◽  
Solution Culture ◽  
Al Tolerance ◽  
Physiological Basis ◽  
Root Regrowth ◽  
Selection Intensities ◽  
Annual Medicago ◽  
Medicago Species ◽  
Relative Root

A rapid (7 day) solution-based screening test was developed using 15 annual Medicago cultivars and one M. sativa. Based on a relative root regrowth after exposures to aluminium (Al), Zodiac (M. murex), Orion (M. sphaerocarpos) and the M. polymorha cultivars Santiago, Cavalier and Serena had the greatest Al tolerance. Herald (M. littoralis) and Rivoli (M. tornata) were most sensitive. Ranking for Al tolerance from the solution culture correlated well (r = 0.80) with ranking for tolerance of the 16 genotypes grown in an acidic soil (unlimed pHCa 4.1). We screened 17 Australian populations of lucerne (M. sativa) using a 24 h ‘pulse’ of 75 µmol/L Al, and a three day ‘recovery’ of 10 µmol/L Al. We identified and recovered plants with a root regrowth of ≥5 mm in all 17 populations with selection intensities of 2 to 4%. Four of these selected populations (Aurora, UQL-1, A513 and TO2-011) were polycrossed within each population to produce four populations of seed from the cycle 1 selections. The length of root regrowth under Al stress was improved for all four populations of cycle 1 selection (P ≤ 0.001; from 2.6 mm for the original populations to 6.3 mm for the cycle 1 selections). In a subsequent experiment the cycle 2 selections from Aurora, UQL-1 and TO2-011 had significantly greater root regrowth than both the cycle 1 selections (P ≤ 0.001; 8.3 cf. 6.6 mm) and the unselected populations (3.0 mm). The selections from TO2-011 appeared to have greater improvement in the average length of root regrowth after 2 cycles of selection. Selected germplasm was more tolerant than GAAT in our evaluation. Based on estimation of realised heritability, it seemed likely that higher selection intensities would give more rapid improvements in tolerance. Our studies have not investigated the physiological basis of any tolerance of Al which we observed.

scholarly journals The Use of Microalgae and Cyanobacteria in the Improvement of Agricultural Practices: A Review on Their Biofertilising, Biostimulating and Biopesticide Roles

2021 ◽  
Vol 11 (2) ◽  
pp. 871
Author(s):  
Ana L. Gonçalves
Keyword(s):  
Bioactive Compounds ◽  
Higher Plants ◽  
Agricultural Practices ◽  
Growth Stimulation ◽  
Environmental Problems ◽  
Worldwide Population ◽  
Photosynthetic Microorganisms ◽  
Phosphorus And Potassium ◽  
Different Levels ◽  
Cyanobacterial Biomass

The increase in worldwide population observed in the last decades has contributed to an increased demand for food supplies, which can only be attained through an improvement in agricultural productivities. Moreover, agricultural practices should become more sustainable, as the use of chemically-based fertilisers, pesticides and growth stimulants can pose serious environmental problems and lead to the scarcity of finite resources, such as phosphorus and potassium, thus increasing the fertilisers’ costs. One possible alternative for the development of a more sustainable and highly effective agriculture is the use of biologically-based compounds with known activity in crops’ nutrition, protection and growth stimulation. Among these products, microalgal and cyanobacterial biomass (or their extracts) are gaining particular attention, due to their undeniable potential as a source of essential nutrients and metabolites with different bioactivities, which can significantly improve crops’ yields. This manuscript highlights the potential of microalgae and cyanobacteria in the improvement of agricultural practices, presenting: (i) how these photosynthetic microorganisms interact with higher plants; (ii) the main bioactive compounds that can be isolated from microalgae and cyanobacteria; and (iii) how microalgae and cyanobacteria can influence plants’ growth at different levels (nutrition, protection and growth stimulation).

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