Abstract

The constantly increasing demand for agricultural produce from organic and conventional farming calls for new, sustainable, and biocompatible solutions for crop protection. The overuse of fungicides leading to contamination of both produce and environment and the emergence of plant pathogenic fungi that are resistant to conventional treatments warrant the need for new methods to combat fungal infections in the field. We here deliver the follow-up study to our research on the Photodynamic Inactivation (PDI) of plant pathogenic bacteria (Glueck et al. in Photochem Photobiol Sci 18(7):1700–1708, 2019) by expanding the scope to fungal pathogens. Both fungal species employed in this study—Alternaria solani and Botrytis cinerea—cause substantial crop and economic losses. Sodium magnesium chlorophyllin (Chl, approved as food additive E140) in combination with Na2EDTA and the chlorin e6 derivative B17-0024 holding cationic moieties serve as eco-friendly photoactive compounds. Effectiveness of the antifungal PDI was measured by inhibition of growth of mycelial spheres (average diameter 2–3 mm) after incubation with the photosensitizer for 100 min and subsequent illumination using a LED array (395 nm, 106.6 J cm−2). One hundred micromolar Chl combined with 5 mM Na2EDTA was able to successfully photokill 94.1% of A. solani and 91.7% of B. cinerea samples. PDI based on B17-0024 can completely inactivate A. solani at 10 times lower concentration (10 µM); however, for B. cinerea, the concentration required for complete eradication was similar to that of Chl with Na2EDTA (100 µM). Using a plant compatibility assay based on Fragaria vesca, we further demonstrate that both photosensitizers neither affect host plant development nor cause significant leaf damage. The plants were sprayed with 300 µL of treatment solution used for PDI (one or three treatments on consecutive days) and plant growth was monitored for 21 days. Only minor leaf damage was observed in samples exposed to the chelators Na2EDTA and polyaspartic acid, but overall plant development was unaffected. In conclusion, our results suggest that sodium magnesium chlorophyllin in combination with EDTA and B17-0024 could serve as effective and safe photofungicides.Graphical abstract

Highlights

  • Since the industrial revolution, our society must cope with an ever-growing world population on one hand and a decline in available arable land per person on the other hand [1, 2]

  • This study is a continuation of our previous work published in Photochemical and Photobiological Sciences in 2019 [16] by extending the application spectrum of Photodynamic Inactivation with chlorin molecules from bacterial to fungal phytopathogens

  • In face of expiring approvals for substances used in plant protection as well as the rising demand of organically farmed agricultural produce and considering the strict regulations regarding plant protection that come with it, Photodynamic Inactivation (PDI) might emerge at exactly the right time to present an alternative approach for fighting fungal phytopathogens

Read more

Summary

Introduction

Our society must cope with an ever-growing world population on one hand and a decline in available arable land per person on the other hand [1, 2]. According to the American Phytopathological Society, the global production of tomato was about 159 million tons and the production of potato 375 million tons in 2011 [3]. Phytopathogenic fungi have the potential to spread by air, animals, contaminated soil or water and have the potential to obliterate entire harvests. This situation is further aggravated by the rise of resistant fungal strains

Objectives
Methods
Results
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.