Abstract:
Bioactive compounds play a pivotal role in orchestrating the defense mechanisms of
plants, one such potent bioactive compound is dodecanoic acid, which is found to be
present in wild papaya genotypes like Vasconcellea candamarcensis and Vasconcellea
Cauliflora, but conspicuously absent in cultivated varieties of papaya. This compound
demonstrates promising antiviral activity against Papaya Ring Spot Virus (PRSV). This
study concentrated on synthesis of nanoemulsion of this bioactive compound which
is known for its inherent hydrophobic properties, necessitating conversion into a
hydrophilic form through advanced techniques such as High Energy Homogenization
and Ultra-Sonication. The resulting nanoemulsion exhibited remarkable characteristics,
with a z-average diameter of 52.30 nm, showcasing a distinct spherical droplet
structure, as corroborated by TEM imaging. In assessing its efficacy, plant bioassays
with eight treatments each replicated thrice, were conducted under controlled
glasshouse conditions using mechanical inoculation methods with 45 days old seedlings
of TNAU papaya CO.8 variety. Strikingly, pre-inoculation and co-inoculation with the
nanoemulsion prevented any manifestation of PRSV infection symptoms in papaya
seedlings and also has positive effects on plant growth. However, in the post-inoculation,
seedlings treated with the dodecanoic acid nanoformulation displayed symptoms of
PRSV infection. Further rigorous investigations are underway to pinpoint the optimal
concentration of the nanoformulation for effectively combatting PRSV infection across
various growth stages. Additionally, comprehensive analysis of its molecular properties
is being pursued to unravel the mechanisms underlying its antiviral activity.
