The bacterium Acinetobacter soli was initially discovered in the forest soil of Baekwoon Mountain in the Republic of Korea. The strain A.soli Y-3 is well-known for its ability to produce L-asparaginase, the broader functionalities of A.soli remain unexplored. This study investigated the effect of A.soli, isolated from tomato plants with green wilt symptom, on tomato plants by introducing the bacteria at seed stage, 2-leaf stage and 4-leaf stage. The germination rate, stem height, root length and leaf number were recorded. The introduction of this bacterium into seeds during the seed stage did not affect germination rate but significantly enhanced stem height from the bacterial density of 2.5 x 104 CFU/mL and root length of tomato plants at bacterial densities ranging from 2.5 x 105 CFU/mL to 2.5 x 107 CFU/mL. Conversely, infection at the 2-leaf stage from a density of 2.5 x 104 CFU/mL led to a reduction in root length. Infection at the 4-leaf stage from the same density resulted in decreased stem height and leaf count. A.soli exhibited the capacity to induce auxin activity without gibberellic acid activity. This research sheds light on the multifaceted interaction between A.soli and tomato plants, paving the way for a deeper understanding of their potential applications in agriculture.
