This heavy burden is not lost on phage scientists eager to put their bacteria slayers to the test. Bacteriophages have the potential to be used in a targeted biocontrol approach, where a specific pathogen is eradicated without interfering with the plant’s biosystem. As with any other product used on plants, efficacy and safety can only be guaranteed after several laboratory and field trials for environmental impact. In some cases, such as bacterial soft rot in calla lily and bacterial wilt in tomato and tobacco, phage therapy has long been reported to be effective.
|Figures showing preliminary tests of the curative action of bacteriophage treatment targeting Ralstonia solanacearum. (A) tomato plant withered 7 days after inoculation with R. solanacearum. (B) healthy tomato plant following joint inoculation of R. solanacearum and bacteriophages. Experiments were carried out in greenhouses at the PVBMT research center on Reunion Island. The scale bar represents 10 cm. ⒸRéseau Bactériophage France|
On the other hand, there are numerous other phytopathogens with untapped potential to be explored for the phytopathogens such as citrus greening of oranges caused by Candidatus liberibacter (transmitted by psyllids) and canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae, which was reported to be controlled by streptomycin and thereby induces resistance. Reportedly, in 2005 the citrus greening hiked the cost of oranges to double in Florida, while 40% of orchards in New Zealand were infected by Pseudomonas syringae.
There is a quest to find a competent alternative approach for the devastating phytopathogens through phage therapy trials.
|ⒸHoltappels et al, 2021|
Recommendations can be laid by high throughput research along with preliminary and final field trials for the efficacy to be employed in the agri-ecosystem by a sustainable approach.
Bacteriophage-based biopesticides for Xanthomonads
Xanthomonas is a gram-negative bacteria belonging to the family Xanthomonadaceae. These are economically important bacteria that are pathogenic to more than 400 plant species. Of several devastating plant diseases caused by xanthomonads, few are a bacterial blight, the most serious disease of rice caused by X. oryzae. Together with pv. oryzicola, the causal agent of bacterial leaf streak, both pathogens frequently represent a limiting factor constraining rice production in tropical and subtropical regions, as mentioned by Niño-Liu Et al (2006). bacterial citrus cancer incited by X. citri subsp, which affects all commercial varieties of citrus. Bananas (all types) are affected by bacterial wilt caused by X. vasicola pv. musacearum and cassava are affected by bacterial wilt caused by X. phaseoli pv. manihotis are two majorly affected crops.
So why does this not take place in nature itself?
However, molecular gene design and bacteriophage engineering empower scientists with the ability to design and modify phages based on the application, allowing them to be manipulated to add values and characteristics such as a persistent lytic cycle.
Apparently, bacteriophages can provide us with a shimmering solution for deceased crop yield because of multiple drug-resistant phytopathogens. They provide us an approach to improve not only environmentally, but also socioeconomically.
Limitations of phage application on plants