Natural sciences [2022-07-05]

Fungi and bacteria in the service of plants

— Marcin Behrendt

Many-year old grains are to help mitigate the results of progressing global degradation of the environment and loss of biodiversity.  The ideas on the use of microorganisms in agricultural crops are being researched by the biologists of NCU within the Project NAPENDRIV.

In the result of climatic changes and the decrease of acreage, the system of plant growing is still evolving.  The agriculture is aiming at industrialization and focuses on fast production.  What then could be done to make it in accordance with the nature?  In order to complete this task, it is necessary to find new grounds for cultivation.  One of the ways of developing new terrains for agriculture is the use of high salinity grounds, which exist in large numbers. An example of such grounds in our regions are the areas of Ciechocinek and Inowrocław.   Too high salinity also refers to many other areas in the world and it is linked with the negative activity of the man, such as inappropriate irrigation, deforestation, and intensive fertilization.  Salinity may lead to physiological draught for plants: a plant which is grown in the ground with too low osmotic potential cannot collect water from the environment in which it grows.  This leads to decrease of crops. 

For years, the biologists of NCU have been challenged to deal with the issue of increasing plant immunity to salination through their inoculation with selected microorganisms which exist in extremely salinized areas. It is the microbiome of those areas which affects the growth of plants growing in salinized soil or affected with a draught, which has been proved by the NCU scientists.

Microbiome is a natural set of organisms which are characteristic for a certain species of plants.  In most cases, it is selectively chosen by the plant from the surrounding soil environment. When the soil undergoes degradation or is exposed to long lasting draught, the microbiome in soil changes, and, in order to survive, the plant must adjust to the new conditions. What may occur helpful in the adaptation to unfavorable conditions is the microorganisms, which have already been inhabiting the plant's tissues, i.e., they were present in seeds or have been implemented into the plant in the course of inoculation.

Our research focuses on discovering the natural microbiome of plants in the context of their immunity to stress – explains prof. dr. habil Katarzyna Hrynkiewicz, the director of Chair of Microbiology in the Faculty of Biological and Veterinary Sciences, NCU.  – By the way, we isolate bacteria and fungi which are characteristic for their particular properties promoting the growth of plants in adverse environmental conditions.

The team of professor Hrynkiewicz has, for instance, taken under thorough study the plant Salicornia europaea, which is protected species in Poland, but in some other countries used as a vegetable or a culinary ingredient.

– We have examined this plant both in the context of its natural microbiome and also for the microorganisms adapted to high salination. Having examined those microorganisms, they were used for inoculation, which means for transferring to cultivated plants. We supposed that those specific microorganisms isolated from the natural conditions, from a halophilous plant may, in unfavorable environmental conditions of salination or draught, stimulate the plant's growth, which leads to bigger crops.

In 2021, within the project “Grain cultivation based on nature as a model of sustaining functional biodiversity in future agriculture" (NAPERDIV), the biologists began research on the plant Thinopyrum intermedium (intermediate common wheat), which can be grown in a multiple year cycle.  It is already sowed experimentally in various areas all over Europe, beginning with Sweden down to warmer regions of our continent.  Multiple year systems, similar to natural ecosystems, especially meadows, are an innovative idea which serves to promote nature-based agriculture.

In the currently functioning standards of agriculture, there applies one-year cycle grain cultivation, which involves the ground preparation, sowing, fertilization, spraying, and harvest. After that, the whole cycle starts again.  In this way, farmers interfere in the structure of the soil, and in consequence in its microbiome. The new approach means decrease of labor supplies and reduction of costs for the environment: the level of soil structure destruction and the amount of means for plant protection against pathogens will drop.  In addition, multiple-year cropping has a good impact on soothing climate changes and guarantees a stable plant cover for the soil. Due to this, cultivation can be more profitable and ecological. Therefore, I am trying to promote this project not only in a scientific context, but also among farmers and seed distribution companies – says professor Katarzyna Hrynkiewicz.

NAPERDIV is an international project in which eight teams take part: from Germany, Austria, Belgium, France, Sweden and Romania.  Each team delas with a different issue.  The scientists from Toruń coordinate team of "Crop-associated microbiome", which is responsible for the interaction between plants and microorganisms.  Besides professor Hrynkiewicz, there are postdoc Makoto Kanasugi, PhD from Japan; Edyta Deja-Sikora, PhD; and Bliss Furtado, PhD.  The latter was a doctoral student who carried out earlier research in the European project HORYZONT 2020.  She dealt with Salicornia, the examination of fungus microbiome and the isolation of fungus microorganisms which could stimulate the growth of cultivated plants.  The main focus was on endophytic fungi.  Having selected the best ones which can stimulate the growth, Bliss Furtado transferred them onto grassy plants.  The research was conducted in cooperation with Danish company DLF Seeds A/S.  There Doctor Furtado did a three-month internship during which she took a lot of tests on the use of microbiological inoculants in order to increase plants' tolerance for unfavorable environmental conditions.  Now, with the team from NCU, she examines the soil and plant microbiome, the balance and changes in the microbiome and tries to establish the way in which the microbiome will alleviate the changes. The results of NAPERDIV project may become the basis for legal changes in European Union referring to the agricultural production.  They will contribute to the increase of food safety and creation of new species of plants.  The project will last until 2024.

- An additional aspect of application will be isolation of the microorganisms from the plant existing in the microbiome for a longer period of time and having a positive impact on cultivated plants – concludes professor Hrynkiewicz. – We do hope these bacteria and fungi, selected from hundreds of strains, will be able to be used in inoculation as natural microorganisms which can help in plant growth.