RESPONSES OF POTATO TO HEAT STRESS AND INFECTION WITH VIRUS Y
Every potato gourmet is convinced that it is common in his country, and in fact, the potato is one of the basic ingredients of the menu around the world. It comes from South America, and it landed in Europe in the 16th century thanks to Pizarro and made himself at home for good. In recent years, as a cultivated plant, it was at the forefront of the world in terms of production volume, next to wheat, rice and maize. China and India are in the lead among the world leaders in potato cultivation.
Potatoes land on the tables in many forms and without a doubt the most popular of them are fries, mashed potatoes or simply potatoes “from the water". The palates of people around the world have also won the popular chips.
In Silesia, they eat zimioki, in Poznań they eat pyry, and at the Highlanders’, they eat grula. The demand for potatoes in Poland has been consistently high for several hundred years. In 2021, 7.1 million tons of potatoes were harvested in our country from an area of 0.2 million hectares! Potato breeding is so common that it should come as no surprise that it has also become the subject of much research, especially those which are able to improve their cultivation and avoid the threats that await it from viruses, bacteria, and the climate.
VIRUS Y
The ubiquitous viruses affect not only the human race but also fauna and flora. One of the most dangerous viruses found in potato cultivation (also found in tomato, pepper, and tobacco) is the potato virus Y (PVY). It is common in all regions where this perennial is grown. Contaminated seed potatoes are the main source of potato viruses. The virus is transmitted by over 40 species of aphids in an unstable manner.
What symptoms indicate infection of the potato with the virus described? First of all, superficial rings or arched circles on the potato peel take on light brown color and can delve into the flesh.
Potato plants, in addition to viruses, including virus Y, are exposed to various environmental stresses that can modulate plant-pathogen interactions and potentially cause a further reduction in crop productivity. In order to obtain new information on the phenotypic, physiological, and molecular reactions of contrasting potato genotypes to the individual (virus or heat stress) and combined (virus + heat) stresses, scientists from the Institute of Bioorganic Chemistry of the Russian Academy of Sciences and from the Institute of Physicochemical Biology of the Moscow University Lomonosov investigated the problem. They analyzed the expression of genes encoding pathogenesis-related (PR) proteins and heat shock proteins in two potato cultivars differing in tolerance to elevated temperature and susceptibility to the Y virus. In the simplest terms, they checked how stress and heat increase the risk of Y virus infection of potatoes.
In plants of the Chicago cultivar (heat-sensitive and susceptible to the Y virus), the increase in temperature caused a decrease in the expression of the PR gene, which correlated with the severity of infection with the Y virus (virus accumulation and symptom production). On the other hand, in the Gala variety (thermotolerant and resistant to Y virus), which showed a greater increase in PR gene expression in response to infection with the Y virus, the temperature had no effect on the level of PR transcripts. It’s worth pointing out that over time, the potato plant has evolved many mitigation strategies to deal with heat stress.
THE ROLE OF THE PHYTOTRON CHAMBER
A significant stage for the study was the storage of potato seedlings in a place that would provide ideal conditions for their growth. A place that will create the right temperature, humidity and simulate the right time of day and night. A specialized laboratory device that allows you to control temperature, humidity, and lighting is nothing more than a climatic chamber with a phytotron system. The phytotron chamber has a day and night simulation system with smooth adjustment of the light intensity. As a result, in the described study, potato plants were stored in conditions where the photoperiod was set 16/8 h day/night at 60% relative humidity and 250 μmol m-2 s-1 light intensity. Such a device allows for wide application in climatic research, giving full control of the conditions inside the unit. We often refer to this device as a dynamic climate change chamber.
During the research, scientists of the Institutes mentioned the above-stored plants in a phytotron chamber produced by Pol-Eko-Aparatura. In its offer, Pol-Eko-Aparatura has units with light located in the door and sidewalls, only in the sidewalls, only in the door, and as a panel with over-shelf lighting. The latter was used by the above Institutes for the described research. The over-shelf lighting ensures an even light intensity over the entire shelf, thanks to which all plants have the same conditions for vegetation, and the research is more reliable, giving reliable results. The Pol-Eko-Aparatura phytotron chamber is often used for research purposes by institutes, research centers, and universities.
Pol-Eko-Aparatura is pleased that thanks to the devices developed by the company, it is possible to conduct research that affects the everyday life of each of us. An example is the described study, which certainly increases the awareness of potato growers about the dangers and how to deal with them.