A Phage Therapy Model for the Prevention of Pseudomonas syringae pv. actinidiae Infection of Kiwifruit Plants

Abstract

Great efforts have been made with chemicals and pesticides to contain the spread of Pseudomonas syringae pv. actinidiae (Psa) responsible for kiwifruit canker. Unfortunately, only partial results were obtained for this bacterial pandemic and alternative remedies were proposed to avoid soil pollution and the onset of antibiotic resistance. Among these, phage therapy represents a possible tool with low environmental impact and high specificity. Several phages have been isolated and tested for the capacity to kill Psa in vitro, but experiments to verify their efficacy in vivo are still lacking. In the present study, we demonstrated that the phage φPSA2, previously characterized, contains the spread of Psa inside plant tissue and reduces the symptoms of the disease. Our data are a strong indication for the efficiency of this phage treatment and open the possibility of developing a phage therapy based on φPSA2 to counteract the bacterial canker of kiwifruit.

Scientific and technological advances in the development of sustainable disease management tools: a case study on kiwifruit bacterial canker

“…Recently, the efficacy of phage therapy in mitigating KBC was validated in planta , using several phages from the Podoviridae family ( Flores et al., 2020 ; Song et al., 2021 ; Fiorillo et al., 2023 ). Flores et al.…”

“…More recently, the phage φPSA2 (characterized in Di Lallo et al. (2014) ), also from the Podoviridae family, demonstrated capacity to counteract Psa colonization capacity inside plant tissues and to reduce KBC symptoms in kiwifruit plants ( Fiorillo et al., 2023 ). Hence, combinations of phages must be tested for their suitability to incorporate cocktails with increased antibacterial action.…”

“…Recently, the efficacy of phage therapy in mitigating KBC was validated in planta, using several phages from the Podoviridae family (Flores et al, 2020;Song et al, 2021;Fiorillo et al, 2023). Flores et al (2020) showed Psa load reduction and fewer KBC symptoms after the application of a phage cocktail applied to two-year-old 'Hayward' plants artificially inoculated with Psa.…”

“…For example, Song et al (2021) observed that the phage PPPL-1 significantly reduced the KBC symptoms in six-week-old grafted plants grown in pots (with 'Hayward' and 'Haehyang' as rootstock and scion, respectively), while not confirming enhanced antibacterial capacity of a cocktail combining this phage with two other with known lytic activity against Psa. More recently, the phage jPSA2 (characterized in Di Lallo et al (2014)), also from the Podoviridae family, demonstrated capacity to counteract Psa colonization capacity inside plant tissues and to reduce KBC symptoms in kiwifruit plants (Fiorillo et al, 2023). Hence, combinations of phages must be tested for their suitability to incorporate cocktails with increased antibacterial action.…”

A Genome-Wide Analysis of the Pentatricopeptide Repeat Protein Gene Family in Two Kiwifruit Species with an Emphasis on the Role of RNA Editing in Pathogen Stress

“…Bacterial canker was first reported on Actinidiae chinensis var. deliciosa in Shizuoka, Japan, in 1984, and today, it has been reported worldwide, including in China, Chile, and European countries [ 3 , 4 , 5 ]. Most current kiwifruit cultivars are mainly derived from Actinidia chinensis ( Ach ), such as ‘HongYang’, ‘Hort 16A’, ‘Gold3’, and ‘Hayward’, which are generally sensitive to Psa.…”