Role of Carbohydrate Reserves in the Development of Root Suckers in Populustremuloides

1973 ◽  
Vol 3 (2) ◽  
pp. 243-250 ◽  
Author(s):  
George A. Schier ◽  
John C. Zasada

The role of carbohydrate reserves in initial sucker growth from excised roots of Alaskan and Utahan aspen (Popnlustremuloides Michx.) was investigated by correlating the seasonal variation in sucker production in darkness with the concentration of total nonstructural carbohydrates (T.N.C.) in the roots. Sucker numbers were not correlated with T.N.C. content. Dry weight of suckers per cutting (D.W./C) was a function of T.N.C. percentage and the number of suckers per cutting (No./C). In the additive model, D.W./C = b0 + b1 (No./C) + b2 (T.N.C), T.N.C. was a significant contributor to sucker dry weight. Although dry weight per cutting increased as the number of suckers became larger, dry weight per sucker decreased. Within geographic area, number and dry weight of suckers and T.N.C. percentage were related to both date of collection and clone of origin. Seasonal trends in T.N.C. content were similar in the Utahan and Alaskan roots studied.

1982 ◽  
Vol 60 (3) ◽  
pp. 195-200 ◽  
Author(s):  
James A. Bunce

Net photosynthetic rates, stomatal and mesophyll conductances to CO2 uptake, water soluble and total nonstructural carbohydrates contents, specific leaf weights of fully expanded source leaves, and elongation rates of rapidly expanding leaves were measured on 2 days during a period of water stress in soybean and sunflower plants in a controlled environment. Compared with control plants, elongation rates of expanding leaves and translocation rates of dry weight from source leaves in the light were more reduced by stress than were net photosynthetic rates of source leaves. Over the 8-h light period, the dry weight increase of source leaves was up to 23 mg dm−2 (1.5 × control) higher in stressed plants, but was not in all cases higher in stressed than control plants. In stressed plants a smaller fraction of the increase in dry weight in source leaves in the light was in nonstructural carbohydrates. At the end of the light period, water soluble and total nonstructural carbohydrates were up to 9 mg dm−2 higher in stressed than control leaves in sunflower, but were not higher in soybean. No differences in carbohydrate contents at the end of the light period were found in sunflower between the 2 days of stress, although stress became more severe in terms of lower rates of photosynthesis, translocation, and leaf elongation. The approximately threefold reductions in net photosynthetic rates in stressed leaves were related to both lower stomatal and lower mesophyll conductances. Mesophyll conductances of stressed leaves were not significantly correlated with water soluble carbohydrate content, total nonstructural carbohydrate content, or specific leaf weight in either species.


1979 ◽  
Vol 57 (20) ◽  
pp. 2140-2144 ◽  
Author(s):  
Scott J. Roseff ◽  
John M. Bernard

Seasonal changes in total nonstructural carbohydrates (TNC) levels in aboveground and belowground tissues of Carex lacustris were determined. TNC concentrations of aboveground tissues averaged 15–20% of the dry weight throughout the year, ranging from 31.3% in newly emerged shoots in September to 3.1% in mostly dead shoots in December. Belowground, TNC concentrations ranged from a low of 16.4% in young rhizomes in midsummer to a high of 44.9% in late October.TNC content of shoots was 68.5 g/m2 on May 5, increasing to a peak of 224.5 g/m2on August 5. Levels declined to a low of 31.6 g/m2 by December 5, of which 74% was found in young shoots about to overwinter. Belowground TNC was 107.5 g/m2 on May 8, declined somewhat into June, then increased to a maximum of 240 g/m2 on October 24. The data indicate these belowground reserves are important for the species to overwinter successfully.The difference between the minimum TNC content of the sedge biomass in late May and the peak in October represented a gain over the summer of approximately 205 g/m2.


Weed Science ◽  
1996 ◽  
Vol 44 (3) ◽  
pp. 566-569 ◽  
Author(s):  
Harry T. Cralle ◽  
Rodney W. Bovey

Greenhouse experiments were conducted to assess the storage of nonstructural carbohydrates in the stems and roots of honey mesquite and their mobilization and utilization following defoliation by hand or clopyralid. All leaves were removed by hand from one group of plants while leaving stems intact. Another group received a foliar spray of clopyralid at a sublethal acid equivalent rate of 0.07 kg ha−1. Samplings at treatment on day 0 and at 14, 28, 42, and 58 d after treatment measured leaf area; dry weight of leaves, stems, and roots; and grams and percent total nonstructural carbohydrates in stems and roots. Controls accumulated dry weight and grams total nonstructural carbohydrates in stems and roots, while maintaining a constant percent total nonstructural carbohydrates throughout the experiment. Percent and grams total nonstructural carbohydrates in stems and roots of hand defoliated plants decreased by about one-half from day 0 to 14 as new leaf growth occurred, but increased and returned to pretreatment levels on day 28. A similiar, though slower, pattern of decline and recovery of total nonstructural carbohydrates in stems and roots occurred in response to defoliation by clopyralid. These results showed that the nonstructural carbohydrates in stems and roots of honey mesquite were important sources of carbohydrates to support new leaf regrowth following defoliation by hand or herbicide.


1972 ◽  
Vol 52 (5) ◽  
pp. 763-768
Author(s):  
A. JOHNSTON ◽  
S. SMOLIAK ◽  
D. B. WILSON

Seedlings of crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schult.), cult Summit, slender wheatgrass (Agropyron trachycaulum (Link) Malte), cull Primar, pubescent wheatgrass (Agropyron trichophorum (Link) Richt.), cult Greenleaf, and quack-grass (Agropyron repens (L.) Beauv.) were grown in the greenhouse for 6 weeks. Each week 20 plants of each species were harvested for growth analysis. Dry weight accumulation in A. trichophorum and A. repens exceeded that in A. desertorum and A. trachycaulum, although net assimilation rate and relative growth rate did not differ among species. A. trichophorum excelled in total weight of roots, total leaf weight, leaf area, and leaf area ratio; A. repens excelled in total sheath weight, total weight of topgrowth, and percent total nonstructural carbohydrates. We suggest that the desirable characteristics of A. repens should be utilized in Canadian grass-breeding programs.


2017 ◽  
Vol 7 (4) ◽  
pp. 30-34 ◽  
Author(s):  
O. A. Didur ◽  
Yu. L. Kulbachko ◽  
V. Y. Gasso

<p>The problem of transformation of natural landscapes resulted from the negative technogenic impact is highlighted. It is shown that mining enterprises are powerful anthropo-technical sources of organic and inorganic toxicants entering the environment. Their wastes pollute all components of the ecosystems and negatively influence human health by increasing a risk of disease. The nature of the accumulation of trace elements (Fe, Cu, Zn, Ni, Cd, and Pb) by invertebrate animals of various functional groups under conditions of anthropo-technogenic pressure was studied. The sample plots were located on self-overgrowing sites with ruderal vegetation located in the immediate vicinity of the Mangan ore-dressing and processing enterprise (Dnipropetrovsk region). It is quite naturally that among the studied biogenic microelements (Fe, Cu, Zn and Ni), the phyto-, zoo-, and saprophages in the investigated zone of technogenic pollution most actively accumulate Fe:<em> </em>22758, 17516 and 18884 mg/kg dry weight on average, respectively. There are significant differences (p ≤ 0.05) in the content of studied microelements between saprophages and phytophages. The saprophages accumulate such trace metals as Mn, Cu, Zn and Cd in high quantities, but Ni and Pb – in smaller ones. The saprophagous functional group of invertebrates is an active agent of detritogenesis, in the conditions of modern nature management it acts as a powerful element of ecosystem engineering (habitat transformation), the main ecological role of which is to modify the habitat of other soil biota. In addition, the saprophages fulfil their concentrating geochemical function. They actively participate in the most important soil biochemical process: the formation of humus, the migration of microelements along trophic chains, the biological cycle in general, and provide such supporting ecosystem services as increasing soil fertility and nutrient cycling.</p>


2010 ◽  
Vol 27 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Martin Šlachta ◽  
Jan Frelich ◽  
Tomáš Tonka

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping dataAn analysis of data on the dry weight biomass of coprophagous beetles in standardized dung (4.5 l) was conducted in order to characterize the spatial and the seasonal distribution of the beetles' biomass in cattle pastures and to elucidate their function in dung decomposition. Nested Anova with factors of farm, site (nested in farm), seasonal period and year was used to evaluate the effect of these factors on the biomass of four functional species groups: the dung dwellers ofScarabaeidae(subfamilyAphodiinae), the dung dwellers ofHydrophilidae, the small tunnellers ofScarabaeidae(subfamilyCoprinae) and the large tunnellers ofGeotrupidae. The spatial variation of biomass (between the sites and the farms) was insignificant (P>0.05) in the two dung-dweller groups and in the large-tunnellers group. On the other hand, a significant (P<0.05) seasonal variation of biomass was found in all but the large tunneller group. In dung dwellers, the spring biomass was formed mainly by two species,Aphodius prodromusandA. sphacelatus. In summer, most of the biomass was accounted for bySphaeridium lunatum, S. scarabaeoidesandA. rufipes. In the two tunneller groups,Onthophagus fracticornis, Geotrupes stercorariusandG. spinigerformed a majority of the biomass in dung.


2021 ◽  
Vol 13 (9) ◽  
pp. 5074
Author(s):  
Urooj Kanwal ◽  
Muhammad Ibrahim ◽  
Farhat Abbas ◽  
Muhammad Yamin ◽  
Fariha Jabeen ◽  
...  

Phytoremediation is a cost-effective and environmentally friendly approach that can be used for the remediation of metals in polluted soil. This study used a hedge plant–calico (Alternanthera bettzickiana (Regel) G. Nicholson) to determine the role of citric acid in lead (Pb) phytoremediation by exposing it to different concentrations of Pb (0, 200, 500, and 1000 mg kg−1) as well as in a combination with citric acid concentration (0, 250, 500 µM). The analysis of variance was applied on results for significant effects of the independent variables on the dependent variables using SPSS (ver10). According to the results, maximum Pb concentration was measured in the upper parts of the plant. An increase in dry weight biomass, plant growth parameters, and photosynthetic contents was observed with the increase of Pb application (200 mg kg−1) in soil while a reduced growth was experienced at higher Pb concentration (1000 mg kg−1). The antioxidant enzymatic activities like superoxide dismutase (SOD) and peroxidase (POD) were enhanced under lower Pb concentration (200, 500 mg kg−1), whereas the reduction occurred at greater metal concentration Pb (1000 mg kg−1). There was a usual reduction in electrolyte leakage (EL) at lower Pb concentration (200, 500 mg kg−1), whereas EL increased at maximum Pb concentration (1000 mg kg−1). We concluded that this hedge plant, A. Bettzickiana, has the greater ability to remediate polluted soils aided with citric acid application.


Medicina ◽  
2021 ◽  
Vol 57 (7) ◽  
pp. 723
Author(s):  
Gustavo Cernera ◽  
Marika Comegna ◽  
Monica Gelzo ◽  
Marcella Savoia ◽  
Dario Bruzzese ◽  
...  

Background and objectives: ischemic stroke (IS) is among the most frequent causes of death worldwide; thus, it is of paramount relevance to know predisposing factors that may help to identify and treat the high-risk subjects. Materials and Methods:we tested nine variants in genes involved in thrombotic pathway in 282 patients that experienced IS and 87 that had transient ischemic attacks (TIA) in comparison to 430 subjects from the general population (GP) of the same geographic area (southern Italy). We included cases of young and child IS to evaluate the eventual differences in the role of the analyzed variants. Results: we did not observe significant differences between TIA and the GP for any of the variants, while the allele frequencies of methylene-tetrahydrofolate reductase (MTHFR) C677T, beta-fibrinogen -455G>A and factor (FXIII) V34L were significantly higher in patients with IS than in the subjects from the GP. No significant interaction was observed with sex. Conclusions: the present data argue that some gene variants have a role in IS and this appears to be an interesting possibility to be pursued in large population studies to help design specific strategies for IS prevention.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 788
Author(s):  
Shaban R. M. Sayed ◽  
Shaimaa A. M. Abdelmohsen ◽  
Hani M. A. Abdelzaher ◽  
Mohammed A. Elnaghy ◽  
Ashraf A. Mostafa ◽  
...  

The role of Pythium oligandrum as a biocontrol agent against Pythium aphanidermatum was investigated to avoid the harmful impacts of fungicides. Three isolates of P. oligandrum (MS15, MS19, and MS31) were assessed facing the plant pathogenic P. aphanidermatum the causal agent of Glycine max damping-off. The tested Pythium species were recognized according to their cultural and microscopic characterizations. The identification was confirmed through sequencing of rDNA-ITS regions including the 5.8 S rDNA. The biocontrol agent, P. oligandrum, isolates decreased the mycelial growth of the pathogenic P. aphanidermatum with 71.3%, 67.1%, and 68.7% through mycoparasitism on CMA plates. While the half-strength millipore sterilized filtrates of P. oligandrum isolates degrade the pathogenic mycelial linear growth by 34.1%, 32.5%, and 31.7%, and reduce the mycelial dry weight of the pathogenic P. aphanidermatum by 40.1%, 37.4%, and 36.8%, respectively. Scanning electron microscopy (SEM) of the most effective antagonistic P. oligandrum isolate (MS15) interaction showed coiling, haustorial parts of P. oligandrum to P. aphanidermatum hyphae. Furthermore, P. oligandrum isolates were proven to enhance the germination of Glycine max seedling to 93.3% in damping-off infection using agar pots and promote germination of up to 80% during soil pot assay. On the other hand, P. oligandrum isolates increase the shoot, root lengths, and the number of lateral roots.


2010 ◽  
Vol 70 (4) ◽  
pp. 668-674 ◽  
Author(s):  
P Dieudé ◽  
M Guedj ◽  
J Wipff ◽  
B Ruiz ◽  
G Riemekasten ◽  
...  

BackgroundRecent evidence has highlighted a potential role of interleukin 1β (IL-1β) in systemic sclerosis (SSc). NLRP1 provides a scaffold for the assembly of the inflammasome that promotes the processing and maturation of pro-IL-1β. In addition, NLRP1 variants were found to confer susceptibility to autoimmune disorders.ObjectiveTo study a possible association of the NLRP1 rs6502867, rs2670660 and rs8182352, rs12150220 and rs4790797 with SSc in the European Caucasian population.MethodsNLRP1 single nucleotide polymorphisms were genotyped in 3227 individuals comprising a discovery set (870 SSc patients and 962 controls) and a replication set including individuals from Germany (532 SSc patients and 324 controls) and Italy (527 SSc patients and 301 controls), all individuals being of European Caucasian origin.ResultsConditional analyses revealed a significant association for the NLRP1 rs8182352 variant with both anti-topoisomerase-positive and SSc-related fibrosing alveolitis (FA) subsets under an additive model: p=0.0042, OR 1.23 (95% CI 1.07 to 1.41) and p=0.0065 OR 1.19 (95% CI 1.05 to 1.36), respectively. Logistic regression analysis showed an additive effect of IRF5 rs2004640, STAT4 rs7574865 and NLRP1 rs8182352 risk alleles on SSc-related FA.ConclusionsOur results establish NLRP1 as a new genetic susceptibility factor for SSc-related pulmonary fibrosis and anti-topoisomerase-positive SSc phenotypes. This provides new insights into the pathogenesis of SSc, underlining the potential role of innate immunity in particular in the FA-positive SSc subphenotype, which represents a severe subset of the disease.


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