Exploring heat stress in crops

Question- One of the key topics of your research with Tradecorp is the mode of action of biostimulants. Biostimulants are a trending topic and understanding the way they work is a cutting-edge area of research. Did you have previous experience working with or studying biostimulants and their mode of action? Or was this an innovative project for your research team?

Answer: In our group, we had already worked on several biostimulant projects with companies as well as collaborations with other national and international research institutions. Prof. Antonio Ferrante has been working on biostimulant research for the last 15 years.

Q- This project started a few years ago and, in fact, some of the initial results were presented at the Biostimulants Congress that New AG International organised in Barcelona in November 2019. What were the objectives and expectations you defined at the beginning of the project?

A: The main objective of this project and the related activities was to evaluate the effectiveness of different algae-based and amino acids based biostimulants in managing heat stress.

Q- In the previous question, you talked about the objectives of the project. What types of tests did you carry out for the research and how have you used the results to obtain in depth insights?

A: We adopted a combined research approach including molecular biology, physiology, histochemical and chemical tests to better understand the mode of action and also the plant response to the application of biostimulants, as well as in combination with heat stress. By using RNA sequencing technologies and bioinformatic analysis we individuated the most representative gene families, which were supposedly involved in the plant response to stress and biostimulants.

We initially studied the large amounts of information that were obtained from these analyses and some of the most important physiological pathways involved were then individuated. Based on this information, data was combined with the results of the chemical analyses (e.g. metabolites) and from the in vivo evaluation of the plants' health status (e.g. by the analysis of chlorophyll a fluorescence). Different responses to both stress and biostimulants were also observed at cellular level through the histochemical evaluation and this data was related to the variation in the expression of the relative genes and transcription factors.

Q- In the research, one of the more advanced methods used was transcriptomic analysis which is used to obtain an in-depth understanding of how plant pathways are activated when exposed to different conditions. Do you think these analyses are useful when studying biostimulants? What kind of insights do transcriptomic analyses provide that cannot be obtained from other types of tests?

A: Yes, this strategy is particularly useful when approaching a topic that is not yet completely understood. The later individuation of genes and transcription factors potentially involved in the response to a certain factor/treatment is an option because this analysis has been performed following a non-targeted approach. Other methodologies like real time PCR (RT-PCR) gene expression analysis or analytical chemistry-based approaches work well when there is a more specific target and there are more clues on what to look for. The "omics" approach gives a much broader vision of what's happening at the molecular level. Afterwards, further research can be performed by confirming the findings obtained with the transcriptomic analysis, using other more specific research techniques such as qPCR and biochemical assays.

Q- Through the Biostimulation 360 programme and other communication actions, Tradecorp is emphasising the importance of correct timing when applying biostimulants. What does your research reveal about the importance of timing in terms of application? Do the insights gained from different studies with other type of abiotic stress also apply in the case of heat stress?

A: The timing of biostimulant application is very important, since the efficacy of the products is related to the activation of specific pathways that belong to plants' primary or secondary metabolisms. Earlier (biostimulant) applications can lead to a lack of response when the stress occurs, given that plants can degrade the bioactive molecules. Conversely, applications that come too late can lead to low responses, as the stress can damage the crop when inducing the physiological and biological responses.

Q- In the research carried out with Tradecorp, you have focused on the effects of heat stress on Arabidopsis thaliana. Why Arabidopsis? Will you be working with other types of plants/crops that are used in commercial agriculture?

A: Arabidopsis is one of the best plant models to be used in this kind of experiments. Its genome is well known, and the identification of genes and functions is quite easy compared to other crop species. As a first step into the identification of the main pathways involved in plant responses to these biostimulants, Arabidopsis was the right choice. Once the main mode of action and the most important pathways activated by the treatment have been identified, it will be much easier to move to a commercial crop and to try to confirm those findings.

Q- And talking about what matters to growers, we know results can vary greatly from the lab to real field conditions. Is your research only taking place in the lab or are you also performing trials in what we could call "real field conditions"? Do you have facilities to perform these field experiments?

A: In our University and related facilities we can grow plants and carry out tests at various levels including growing chambers, experimental greenhouses as well as in open fields, under real commercial conditions.

Q- The University of Milan has been collaborating with Tradecorp on this project since 2018. What are your plans for the future? Do you have any other upcoming collaborative projects with Tradecorp? If yes, can you tell us a bit about them?

A: The next steps will be experimentation in real production contexts, by testing different biostimulant formulations on important commercial crops such as rocket and soybean. This will be based on the results and knowledge obtained from the previous experimental trials. These research activities aim to verify whether the information collected in the model plant system can be transferred to cultivated plants.

Q- Finally, could you reveal some more details from the Heat Stress project and any recent advances you have made since you presented your work in Barcelona?

A: We are now defining the last details before submitting a manuscript (for a scientific paper) outlining the most promising results from our first round of experiments and we sincerely hope that it will be published soon. A data analysis of transcriptional profiles reveals that specific pathways related to heat shock proteins (HSPs) were activated and could play a key role in the reduction of cell damage and functionality.

Source: Ag News

Photo Credit: <a href='https://www.freepik.com/photos/food'>Food photo created by freepic.diller - www.freepik.com</a>

Source: Ag News