The effect of a coating material containing organic photoluminophore (PL) on the growth and development of mustard Brassica juncea L. plants colonized with beneficial associative bacteria Pseudomonas putida KT2442 and Rhodococcus erythropolis X5 was studied in vitro and in vivo. Plants grown with the use of microbial bacterization in combination with a photoluminophore coating (PLC) had significantly faster growth rates in vitro (2.1 times faster, P. putida; 1.8 times faster, R. erythropolis) than those grown using PLC alone (1.2 times faster). The leaves of plants grown with PLC had higher contents of glucose and fructose (28.4 ± 0.3% more glucose and 60.4 ± 0.3% more fructose accumulated compared to plants grown without PLC). It was found that seed weights and seed number increased 1.9-fold and 1.6-fold, respectively, for plants grown with PLC and colonized with beneficial P. putida KT2442 bacteria. The stimulatory effect of PLC on photosynthetic parameters of Photosystem II (PSII) was observed in colonized plants grown in vitro. For the first time, it was shown that providing plants with a PLC for only 4 weeks may make it possible to support further plant growth without PLC to obtain higher yields in the future. Thus, PLCs that convert shorter-wavelength radiation into red light may induce enhancement of biochemical processes not only in plants but also in microorganisms that supply plants with growth regulators and other active compounds. The results indicate the need for further research to understand the mechanisms of photobiological and photoregulatory systems in the interaction of microbes and plants.