How do bacteria affect crops? Interview with dr Weronika Babińska-Wensierska

fot. Marcel Jakubowski

Dr Weronika Babinska-Wensierska is the first person to graduate from the Intercollegiate Doctoral School of Biotechnology at UG and MUG, and she defended her PhD with honours. We invite you to read a conversation on the state of natural water bodies and the impact of bacteria on agricultural land.

 

Julia Bereszczyńska: - In your doctoral thesis, you looked, among other things, at the issue of natural water bodies as potential sources of bacteria, which in turn cause the symptoms of wet rot and blackleg on potatoes. What is the status of reservoirs in Pomerania in this respect?

Dr Weronika Babinska-Wensierska: - Prof. Ewa Łojkowska's team has been conducting monitoring studies for the occurrence of bacteria of the Pectobacterium and Dickeya genera in potato fields in Poland since 1996. Continuing this research, I decided to investigate Pomeranian lakes as part of my PhD thesis to determine whether these water bodies could be a source of Pectobacterium spp. or Dickeya spp. and contribute to their spread in the environment. During the two-year monitoring, I surveyed nine lakes and took water samples as a qualified diver not only from the surface but also from depths of 5 m, 10 m, 15 m and 20 m. In addition, bottom sediment samples from a depth of 20 m and water samples taken near the shore were included in the analysis. Concerning the status of water bodies in Pomerania, I can only comment on the presence of pectinolytic bacteria in them. Based on the surveys carried out, we know that bacteria of the genera Dickeya and Pectobacterium are only found on the surface of water bodies. In addition, of the nine lakes studied, we were only able to isolate pectinolytic bacteria from two. It is also worth noting that this research was the first time that water bodies were monitored for bacteria at different depths.

 

- Is irrigation of potato fields with groundwater a good or bad idea?

- Based on the research described in question 1, it was shown that pectinolytic bacteria were only isolated from the water surface near the shore. On this basis, it can be assumed that the use of water drawn from greater depths instead of from the surface for crop irrigation may help to reduce the spread of pectinolytic bacteria on agricultural land.

 

- Are the bacteria in the Pectobacteriaceae family that you studied dangerous to humans? If so, what can they cause? Can the consumption of an infected potato have any health consequences?

- Bacteria in the family Pectobacteriaceae, including genera such as Dickeya and Pectobacterium, do not usually pose a direct threat to humans. They are mainly plant pathogens, causing diseases such as blackleg and wet rot, especially in potatoes. If a potato infected with these bacteria were eaten, it would not be harmful to human health. However, potato tubers showing symptoms of blackleg and wet rot are characterised by, among other things, macerated tissue and an unpleasant odour, and I would therefore recommend eating healthy-looking vegetables, including potatoes, to avoid the potential risks associated with infection with other microorganisms or toxic substances.

 

- In your thesis, you stated that the severity of diseases caused by bacterial plant pathogens is also dependent on environmental conditions. What exactly are the conditions that influence this?

- Many environmental factors can influence the development and severity of plant diseases caused by bacterial pathogens such as Dickey's and Pectobacterium. Soil moisture - if high, this favours the development of pectinolytic bacteria. Temperature - optimum temperatures that favour bacterial growth can affect the severity of plant diseases. This is usually around 28ºC, although this varies between species. Agricultural practices - the way crops are grown, the use of fertilisers, and other agricultural practices can affect plant health and susceptibility to infection. Also, proper hygiene of agricultural machinery so as not to introduce bacterial pathogens into the field and thus into the potato tubers at harvest.

 

- Looking at agriculture, both in Pomerania and nationally, are these bacteria wreaking havoc on crops? How does this affect harvest? Are the losses large?

- As far as I am aware, no statistics are kept when it comes to losses caused by bacteria of the genera Dickeya and Pectobacterium in Poland. However, in general, bacteria of the Pectobacteriaceae family cause significant damage to plant crops, especially potatoes. Dickeya and Pectobacterium spp. in 2012 were listed among the ten most dangerous phytopathogens in terms of the economic losses they cause. In contrast, other data, from Israel, report yield reductions of between 20% and 25% for different potato varieties as a result of Dickeya spp. in fields.

 

- Thinking about the issue more globally, what challenges do we face in terms of controlling the spread of plant diseases?

- Controlling the spread of plant diseases is a significant challenge, and several key aspects deserve attention, especially in a global context. Globalisation of trade and transport: increased international trade in plants, seeds and agricultural products favours long-distance transmission of pathogens. Border control and quarantine measures are key but require coordinated international action. Climate change: changes in climatic conditions can affect the spread of plant diseases as new areas become more friendly to pathogens or are more susceptible. This requires adaptation of control strategies to changing environmental conditions. Resistance to plant protection products: excessive and inappropriate use of plant protection products can lead to the evolution of resistance in pathogens. It is necessary to develop new control methods and rotate different active substances to maintain their effectiveness. Monitoring and early detection: plant disease monitoring systems and early detection of new pathogens are crucial for rapid response and containment.

 

- Thank you very much for the interview.

Julia Bereszczyńska, photo by Marcel Jakubowski/Press Office