#ultrastructure

Expanded View

Microscopists strive for greater resolution – to pick out details as they zoom in further on life. But there are always limits, and cellular life often remains unseen inside tiny, seemingly 'invisible' ultrastructures. While some electron microscopes are up to the job, they're expensive, so here researchers try a different approach – rather than zooming in, why not stretch the cell? Blow it up, so its hidden details are easier to see, like the writing on a birthday balloon (although 20,000 times smaller). This new form of expansion microscopy embeds a human cancer cell in a cocktail of polymers which swell, stretching the cell while keeping some important features of cell division – chromosomes (highlighted in red) and spindle fibres (blue) in place. These techniques can be combined with more common confocal microscopes, allowing labs to examine elusive ultrastructure in healthy and diseased cells without the inflated costs.

Written by John Ankers

Image by Ons M’Saad

Department of Cell Biology, Yale School of Medicine, New Haven, CT, USA

Image copyright held by the original authors

Research published in Nature Communications, July 2020

The defeat of the fruits of fungal diseases is currently an important issue of plant science and is also of great economic importance. With the help of microscopic methods the leaves and fruits surface tissues of plants of four genera of the Maloideae subfamily were screened: Malus Mill., Pyrus L., Cydonia Mill., Mespilus L. and attempts were made to explain the dependence of mycosis damage on micro structural features. The species composition of fungi that cause damage to the Maloideae leaves and fruits in the Russia southern regions is analyzed. It is established that among pathogens with different types of parasitism there are common excitants, as well as highly specialized responses as on Mespilus germanica L. Higher resistance to the complex of fungal diseases, in comparison with apple and pear, was found in quince and medlar. This stability at the initial stage of the pathological process is associated with structural features such as micro morphology of the fruits and stomata cuticle in the abaxial epidermis of leaves. The leaves stomatal openings of medlar are narrow with raised outgrowths, on the surface of the fruits – the layered structure of the cuticular layer. Quince has a continuous cuticular cover. In the species least affected by mycoses, a high content of very-longchain fatty acids in the external tissues was revealed, which may be one of the factors of resistance to pathogens. In addition, the studied species revealed differences in the content of polyphenols, which can inhibit the development of pathogens at the stage of their penetration. Thus, during the study, using the example of the Maloideae subfamily, we identified several factors of passive immunity of plants. Conventionally, they can be divided into two groups: mechanical and chemical, working at various stages of pathogen penetration into plant organism. Author(s) Details Alexander S. Voronkov   Timiryazev Institute of Plant Physiology RAS, 127276, Moscow, Botanicheskaya St. 35, Russia. Tamara Kh. Kumachova Russian State Agrarian University – Moscow Timiryazev Agricultural Academy, 127550, Moscow, Timiryazevskaya St. 49, Russia. Tatiana V. Ivanova   Timiryazev Institute of Plant Physiology RAS, 127276, Moscow, Botanicheskaya St. 35, Russia.

View Book: -