Impact of Light-Emitting Diode (LED) Lighting and Microbial Inoculum on Rice Seedling Phenotype, Physiology, and Microbial Communities

Raising rice (Oryza sativa L.) seedlings under LED lighting reduces nursing space and labor while ensuring health and quality. This study compared rice seedlings grown under natural light (NL) and LED lighting (AL), with and without inoculation of the beneficial fungus Falciphora oryzae. The results showed that NL-grown seedlings had greater stem diameters and shoot and root weights. The AL treatment induced higher plant height in some cultivars and longer root lengths in others. Microbial inoculation minimally affected phenotypes but increased root length in one cultivar. Chlorophyll content was unchanged across the treatments, while malondialdehyde (MDA) levels rose under AL in one cultivar, and catalase (CAT) levels were elevated in two cultivars under AL. Microbial inoculation reduced CAT levels under AL. The AL + M treatment increased rhizosphere prokaryotic community evenness and altered prokaryotic compositions in the rhizosphere and root endosphere, with Burkholderia and Paraburkholderia taxa showing differential responses to the treatments. These findings underscore the role of microbial inoculation in enhancing rice seedling health and resilience under artificial lighting, contributing to sustainable agriculture and food security.