Plant Growth-Promoting Potential of Deinococci spp. Evaluated Using Zea mays and Lens Culinaris Crops

Abstract

Microbial-mediated plant growth promotion is an eco-friendly and sustainable approach under unprecedented climatic conditions. Today, available beneficial microbes for plant growth promotion have some limitations such as required specific growth conditions, etc. However, a bacterium family Deinococci spp. identified has some extraordinary, radioresistance and desiccation tolerance capabilities, that can help it survive in extremely harsh conditions, irrespective of serious injury and unpredictable climatic conditions, making it special compared to other microbial bioagents. The present investigation demonstrated the plant growth-prompting potential of Deinoccci, in maize (Zea mays) and lentil (Lens culinaris) crops. The experiment was conducted both in in vitro (laboratory) and in vivo (glasshouse) conditions. The results indicate that different species of Deinococci exhibited varying responses in maize and lentil. For instance, the combined (seed bio-priming and soil pre-inoculation) application of D. radiodurans 38 in maize enhanced a significantly higher percentage of seed germination, maximum shoot (47.72 cm) and root (10.19 cm) length, fresh shoot (3.44 g) and root (0.39 g) weight, dry shoot (0.348 g) and root (0.095 g) weight, strong seedling vigor (5791.6) and R:S (0.214), while D. radiodurans R1 in lentil promote cent per cent seed germination, maximum shoot (24.3 cm) and root (7.94 cm) length, fresh shoot (0.40 g) and root (0.032 g) weight, dry shoot (0.085 g) and root (0.023 g) weight, strong seedling vigor (3028.6) and R:S (0.33) as compared to individual application. Overall, our findings suggested that the combined application of the Deinococci radiodurans 38 and R1 showed higher plant growth promotion in maize and lentil, respectively, as compared to other strains. This suggests that it could be potentially used as an efficient alternative to promote growth in maize and lentil crops for both seed germination and biomass development irrespective of unpredictable environmental conditions.