scholarly journals Effect of Phosphinothricin on Transgenic Downy Birch (Betula pubescens Ehrh.) Containing bar or GS1 Genes

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1067 ◽  
Author(s):  
Vadim G. Lebedev ◽  
Konstantin V. Krutovsky ◽  
Konstantin A. Shestibratov

Weeds are a big problem in agriculture and forestry, and herbicides are the main tools to control them. Phosphinotricin (ammonium glufosinate, PPT) is one of the most effective non-selective herbicides, to which weeds hardly gain resistance, but the reasons for its effect and toxicity to plants are still unclear, and especially, it is little studied in trees, including transgenic ones. We studied the physiological responses of downy birch (Betula pubescens Ehrh.) containing the herbicide resistance bar gene or the cytosol glutamine synthetase GS1 gene (the target enzyme of the herbicide) to PPT-based Basta herbicide treatment in various doses under open-air conditions during two years. Birch saplings with the bar gene were resistant to a double field dose (10 L/ha), but the expression of the GS1 gene only slightly increased resistance compared to the control. Herbicide treatment increased the ammonium level in leaf tissue by 3–8 times, but this, apparently, was not the main cause of plant death. Among leaf pigments, chlorophyll B was the most resistant to PPT, and carotenoids were the most sensitive. Responses of birch trees with the GS1 gene (accumulation of ammonium, pigment content, and dehydration) during treatment with a low dose of herbicide were less pronounced than in control plants. One-year-old control and transgenic plants with the GS gene died after 2.5 L/ha treatment, and two-year-old plants lost foliage after such treatment but remained alive and developed buds four weeks after treatment. Herbicide treatment of plants with the bar gene did not cause significant deviations in height (first year) or the accumulation of aboveground biomass (second year). The obtained results improve our understanding of the effect of PPT on woody plants and can be used both to clarify mechanisms of herbicide action and in plantation forestry.

2020 ◽  
Vol 15 (7-8) ◽  
pp. 476-482
Author(s):  
P. M. Evlakov ◽  
O. A. Fedorova ◽  
T. A. Grodetskaya ◽  
O. V. Zakharova ◽  
A. A. Gusev ◽  
...  

2018 ◽  
Vol 15 ◽  
pp. 28-44
Author(s):  
Dhirendar Kumar Pradhan ◽  
Christine Cahalan ◽  
Sunita Ulak

Climate is one of the major factors that govern the distribution of tree species. Climate change has already affected the growth, structure and distribution of trees and woodlands. Global climate change projections are wetter winters, drier summers and significance changes in temperature regimes in the next few decades. The main objective of this study was to experimentally demonstrate the effects of decline in summer rainfall, as predicted by UKCP09/IPCC, on height and diameter growth in two co-occurring silver birch (Betula pendula Roth) and downy birch (Betula pubescens Ehrh) and provide further understanding of the changes in growth and development in response to a decrease in water availability. One-year-old seedlings were grown in a temperature-controlled greenhouse for eight weeks in a split-plot experimental design. Their height and diameter were measured and analyzed. Result showed that plant height and diameter was significantly reduced with increased water stress. B. pendula showed higher physiological traits indicating that this species can perform better than B. pubescensin water-deficit conditions.


Botany ◽  
2014 ◽  
Vol 92 (7) ◽  
pp. 477-484 ◽  
Author(s):  
Mikhail V. Kozlov ◽  
Elena L. Zvereva

Although the premature abscission of leaves damaged by herbivores has been discovered decades ago, the reduction in leaf life span caused by herbivory remains poorly documented, and the sources of variation in the magnitude of this effect have only rarely been studied. We aimed at exploring the effects of several herbivore species (at their background densities) and simulated herbivory on the leaf life span of downy birch, Betula pubescens Ehrh. Leaves damaged by herbivores abscised on average 12.6 days earlier and punched leaves 3.5 days earlier than the intact leaves of the control shoots. Different herbivores reduced the life span of the birch leaves from 0% to 27% depending on the intensity and timing of the damage but not on the insect feeding guild. The reduction in leaf life span was greater when the damage was imposed on expanding and growing leaves compared with mature leaves. However, the effect of herbivore species remained significant after accounting for intensity and timing of damage. This fact, together with greater reduction in leaf life span due to natural herbivory compared with mechanical damage, indicates that premature abscission in response to injury is considerably enhanced by insect-specific elicitors.


Silva Fennica ◽  
1981 ◽  
Vol 15 (1) ◽  
Author(s):  
K. Bhat ◽  
Ari Ferm ◽  
Matti Kärkkäinen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. A. Salinero-Fort ◽  
F. J. San Andrés-Rebollo ◽  
J. Cárdenas-Valladolid ◽  
M. Méndez-Bailón ◽  
R. M. Chico-Moraleja ◽  
...  

AbstractWe aimed to develop two models to estimate first AMI and stroke/TIA, respectively, in type 2 diabetes mellitus patients, by applying backward elimination to the following variables: age, sex, duration of diabetes, smoking, BMI, and use of antihyperglycemic drugs, statins, and aspirin. As time-varying covariates, we analyzed blood pressure, albuminuria, lipid profile, HbA1c, retinopathy, neuropathy, and atrial fibrillation (only in stroke/TIA model). Both models were stratified by antihypertensive drugs. We evaluated 2980 patients (52.8% women; 67.3 ± 11.2 years) with 24,159 person-years of follow-up. We recorded 114 cases of AMI and 185 cases of stroke/TIA. The factors that were independently associated with first AMI were age (≥ 75 years vs. < 75 years) (p = 0.019), higher HbA1c (> 64 mmol/mol vs. < 53 mmol/mol) (p = 0.003), HDL-cholesterol (0.90–1.81 mmol/L vs. < 0.90 mmol/L) (p = 0.002), and diastolic blood pressure (65–85 mmHg vs. < 65 mmHg) (p < 0.001). The factors that were independently associated with first stroke/TIA were age (≥ 75 years vs. < 60 years) (p < 0.001), atrial fibrillation (first year after the diagnosis vs. more than one year) (p = 0.001), glomerular filtration rate (per each 15 mL/min/1.73 m2 decrease) (p < 0.001), total cholesterol (3.88–6.46 mmol/L vs. < 3.88 mmol/L) (p < 0.001), triglycerides (per each increment of 1.13 mmol/L) (p = 0.031), albuminuria (p < 0.001), neuropathy (p = 0.01), and retinopathy (p = 0.023).


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jacques P. Brown ◽  
Jonathan D. Adachi ◽  
Emil Schemitsch ◽  
Jean-Eric Tarride ◽  
Vivien Brown ◽  
...  

Abstract Background Recent studies are lacking reports on mortality after non-hip fractures in adults aged > 65. Methods This retrospective, matched-cohort study used de-identified health services data from the publicly funded healthcare system in Ontario, Canada, contained in the ICES Data Repository. Patients aged 66 years and older with an index fragility fracture occurring at any osteoporotic site between 2011 and 2015 were identified from acute hospital admissions, emergency and ambulatory care using International Classification of Diseases (ICD)-10 codes and data were analyzed until 2017. Thus, follow-up ranged from 2 years to 6 years. Patients were excluded if they presented with an index fracture occurring at a non-osteoporotic fracture site, their index fracture was associated with a trauma code, or they experienced a previous fracture within 5 years prior to their index fracture. This fracture cohort was matched 1:1 to controls within a non-fracture cohort by date, sex, age, geography and comorbidities. All-cause mortality risk was assessed. Results The survival probability for up to 6 years post-fracture was significantly reduced for the fracture cohort vs matched non-fracture controls (p < 0.0001; n = 101,773 per cohort), with the sharpest decline occurring within the first-year post-fracture. Crude relative risk of mortality (95% confidence interval) within 1-year post-fracture was 2.47 (2.38–2.56) in women and 3.22 (3.06–3.40) in men. In the fracture vs non-fracture cohort, the absolute mortality risk within one year after a fragility fracture occurring at any site was 12.5% vs 5.1% in women and 19.5% vs 6.0% in men. The absolute mortality risk within one year after a fragility fracture occurring at a non-hip vs hip site was 9.4% vs 21.5% in women and 14.4% vs 32.3% in men. Conclusions In this real-world cohort aged > 65 years, a fragility fracture occurring at any site was associated with reduced survival for up to 6 years post-fracture. The greatest reduction in survival occurred within the first-year post-fracture, where mortality risk more than doubled and deaths were observed in 1 in 11 women and 1 in 7 men following a non-hip fracture and in 1 in 5 women and 1 in 3 men following a hip fracture.


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