Photoinactivation of Pseudomonas syringae pv. actinidiae in kiwifruit plants by cationic porphyrins
- 234 Downloads
The studied cationic porphyrins formulation allows an effective photoinactivation of Pseudomonas syringae pv. actinidiae in kiwifruit leaves under sunlight irradiation, without damaging the plant.
Pseudomonas syringae pv. actinidiae (Psa) is a Gram-negative phytopathogenic bacterium responsible for canker on kiwifruit plant. Over the last decade, this bacterium dramatically affected the production of this fruit worldwide, causing significant economic losses. In general, Psa control consists in the application of copper which are toxic and persist in the environment. The application of antimicrobial photodynamic therapy (aPDT) as an alternative to inactivate Psa has already been demonstrated in recent studies that showed a 4 log Psa reduction using the cationic porphyrin Tetra-Py+-Me as photosensitizer (PS) and 3 consecutive cycles of treatment with a light irradiance of 150 mW cm−2. The present work aimed to evaluate the photodynamic efficiency of a new formulation constituted with five cationic porphyrins as PS in Psa inactivation. This new formulation was prepared to have as main component the tri-cationic porphyrin which is considered one of the most efficient photosensitizers in the photoinactivation of microorganisms. The in vitro study with a PS concentration of 5.0 µM and low irradiance, showed a 7.4 log photoinactivation after 60 min. Posteriorly, several assays were performed with the PS at 50 µM on kiwifruit leaves (ex vivo), under different conditions of light and inoculation. The ex vivo assays with artificially contaminated leaves showed a 2.8 and 4.5 log inactivation with low irradiance and sunlight, respectively, after 90 min. After a second treatment with sunlight, a 6.2 log inactivation was achieved. The photoinactivation on naturally contaminated leaves was about 2.3 log after 90 min sunlight irradiation. Ten consecutive cycles of phototreatment in sub-lethal conditions showed that Psa does not develop resistance, nor recover viability. The results suggest that aPDT can be an alternative to the current methods used to control Psa, since it was possible to inactivate this bacterium under sunlight, without damaging the leaves.
KeywordsAntimicrobial photodynamic therapy Pseudomonas syringae Cationic porphyrins Kiwi Resistance development
The authors are thankful to the University of Aveiro, to FCT/MEC for the financial support to the Centre for Environmental and Marine Studies (CESAM) unit (Project Pest-C/MAR/LA0017/2013) and QOPNA research Unit (FCT UID/QUI/00062/2013), through national founds and, co-financed by the FEDER, within the PT2020 Partnership Agreement, and to the Portuguese NMR Network. MM thank to the Fundação para a Ciência e a Tecnologia FCT for her doctoral Grant (SFRH/BD/112517/2015).
- Beresford RM, Tyson JL, Henshall WR (2017) Development and validation of an infection risk model for bacterial canker of Kiwifruit, using a multiplication and dispersal concept for forecasting bacterial diseases. Phytopathology 107:184–191. https://doi.org/10.1094/PHYTO-04-16-0166-R CrossRefPubMedGoogle Scholar
- de Menezes HD, Rodrigues GB, Teixeira SP et al (2014b) In vitro photodynamic inactivation of plant-pathogenic fungi Colletotrichum acutatum and Colletotrichum gloeosporioides with novel phenothiazinium photosensitizers. Appl Environ Microbiol 80:1623–1632. https://doi.org/10.1128/AEM.02788-13 CrossRefPubMedPubMedCentralGoogle Scholar
- de Menezes HD, Tonani L, Bachmann L et al (2016) Photodynamic treatment with phenothiazinium photosensitizers kills both ungerminated and germinated microconidia of the pathogenic fungi Fusarium oxysporum, Fusarium moniliforme and Fusarium solani. J Photochem Photobiol B Biol 164:1–12. https://doi.org/10.1016/j.jphotobiol.2016.09.008 CrossRefGoogle Scholar
- Fresh Plaza (2017a) Seeka sufrió grandes perjuicios durante el brote de Psa. http://www.freshplaza.es/article/109047/Nueva-Zelanda-Seeka-sufrió-grandes-perjuicios-durante-el-brote-de-Psa. Accessed 21 Aug 2017
- Fresh Plaza (2017b) Kiwi bacteriosis - increased virulence compared to 2010.http://www.freshplaza.com/article/179242/Kiwi-bacteriosis-increased-virulence-compared-to-2010. Accessed 21 Aug 2017
- INDUSTRIER NORDOX (2007) Ficha técnica—Cobre nordox® 75 wg. http://www.nordox.no/plant-protection/nordox-75-wg/. Accessed 13 Apr 2018
- James DC (2008) Advances in photodynamic therapy: basic, translational, and clinical, 1st edn. Eng Med BiolGoogle Scholar
- Kiwifruit Vine Health (2015) Psa-V Seasonal management wall chart 2016–17. http://www.kvh.org.nz/vdb/document/99346. Accessed 28 Nov 2016
- Kiwifruit Vine Health (2016) Psa-V Best Practice Guide. http://www.kvh.org.nz/vdb/document/101436. Accessed 4 Nov 2016
- Kiwifruit Vine Health (2017) Psa-V. http://www.kvh.org.nz/about_Psa. Accessed 18 Apr 2017
- Marciel L, Mesquita MQ, Ferreira R et al (under final revision) An efficient formulation based on cationic porphyrins to photoinactivate Staphylococcus aureus and Escherichia coli. Future Med ChemGoogle Scholar
- Renzi M, Mazzaglia A, Balestra GM (2012) Widespread distribution of kiwifruit bacterial canker caused by the European Pseudomonas syringae pv. actinidiae genotype in the main production areas of Portugal. Phytopathol Mediterr 51:402–409Google Scholar
- Schulin, R, Johnson, A, Frossard E (1995) Copper. In: Alloway BJ (ed) Heavy metals in soils, 2nd edn. Blackie Academic and Profissional, London, pp 175–197Google Scholar
- University of Sidney (2003) Disease management: Chemical Control. http://bugs.bio.usyd.edu.au/learning/resources/PlantPathology/disease_mgmt/chemical_ctrl.html. Accessed 21 Aug 2017
- Wicaksono WA, Jones EE, Casonato S et al (2018) Biological control of Pseudomonas syringae pv. actinidiae (Psa), the causal agent of bacterial canker of kiwifruit, using endophytic bacteria recovered from a medicinal plant. Biol Control 116:103–112. https://doi.org/10.1016/j.biocontrol.2017.03.003 CrossRefGoogle Scholar