Structural changes in Medicago truncatula root nodules caused by short-term aluminum stress

Aluminum in the form of Al³⁺ is one of the most toxic heavy metal pollutants in nature and its effects are primarily root-related. Roots of Medicago truncatula exposed to 50 μM of AlCl₃ for 2 h and 24 h were examined by light and electron microscopy. Changes in the appearance of the host cells, infection threads and bacteroidal tissue occurred during the first 2 h of Al stress. Microscopic observations showed that aluminum: (1) induced thickening of plant cell and infection threads (ITs) walls, (2) stimulated IT enlargement, (3) caused disturbances in bacterial release from the ITs, (4) modified cell vacuolation and induced synthesis of granular material and its deposition in the cytoplasm, (5) and caused structural alterations of organella and bacteroids.     

Applications of <Emphasis Type="Italic">in vitro</Emphasis> culture systems for commercial sugarcane production and improvement

Sugarcane breeding, while key to continued improvement of pest and disease resistance and to increasing sucrose and biomass yields, is constrained by the length of time taken to release a new cultivar (10–14 yr). Forty years of international research into sugarcane in vitro culture has delivered many well-developed systems that are routinely applied to research and commercial activities, namely: (a) micropropagation of genotypes; (b) production of disease-free material from excised apical meristems; (c) international germplasm exchange; (d) generation of somaclones; (e) rapid disease and pest resistance screening; and (f) germplasm conservation. This review outlines several in vitro techniques, discussing how protocols have been tailored to address pertinent research issues and exploring possible commercial applications in the sugar industry to reduce the time frame to release a new cultivar and decrease demands on resources such as land and labour.     

Differences in response to drought stress among highbush blueberry plants propagated conventionally and by tissue culture

Abstract

The effects of drought stress on the morphological and physiological features of highbush blueberry Brigitta Blue plants were investigated. The plants were propagated conventionally by stem cutting (SC) and tissue culture (TC). Micropropagated plants originating from axillary (TC-Ax) and adventitious (TC-Ad) shoots were separated. An additional group consisted of plants propagated several times by stem cuttings, derived from TC mother plants (TC/SC). Different concentrations of polyethylene glycol (PEG) (3% and 7%) were applied to induce drought stress. Parameters such as dry and fresh weight, water content, shoot elongation as well as chlorophyll fluorescence and content were measured. The effect of PEG treatment varied in plants of different origin. Shoot elongation was mainly inhibited in SC plants, whereas TC/SC plants exhibited a stronger reduction of photosystem II efficiency. Fm and Fv differences between TC plants propagated by axillary or adventitious shoots were also observed under control conditions. These epigenotypes also differed in shoot elongation under 7% PEG treatment. The obtained results confirmed the influence of the propagation method of highbush blueberry plants not only on morphological traits, but also on the physiological status.     

Distinct redox state regulation in the seedling performance of Norway maple and sycamore

Journal of Plant Research - Norway maple and sycamore, two Acer genus species, have an important ecological value and different sensitivity to stressing factors being currently aggravated by...     

Glioma 2021 WHO Classification: The Superiority of NGS Over IHC in Routine Diagnostics

Molecular Diagnosis & Therapy - The accurate detection of genetic variants such as single substitutions (IDH1/2, TERT), chromosomal abnormalities (CDKN2A, 1p/19q deletions, and EGFR...     

The effect of physical training on the N-methyl-N-nitrosourea-induced mammary carcinogenesis of Sprague–Dawley rats

The impact of physical activity on carcinogenesis has been demonstrated in many studies. Taking into account the discrepant results of physical exercise on the cell proliferation and apoptosis of breast cancer, we aimed to examine the impact of physical training on N-methyl-N-nitrosourea-(MNU)-induced mammary carcinogenesis. Fifty female rats were divided into four groups according to the intensity of physical activity they undertook. The number of developed tumors, tumor volume, and histopathological diagnoses were noted. Apoptosis and cell proliferation were studied by the number of TUNEL-positive and Ki-67-expressing cells. We demonstrated a statistically significant decrease in the tumor number between all trained groups and the control group. The results were most pronounced in the group with a moderate intensity of training. Moreover, we showed a decrease in tumor volume as training intensity increased, though the differences were not statistically significant. The mean number of TUNEL-positive cancer cells was significantly higher in the training groups than in the control group. These data suggest that physical training, especially of moderate intensity, may alleviate MNU-induced mammary carcinogenesis. The results could suggest that physical exercise-induced apoptosis may be a protective mechanism.