The goal of the present study was to characterize anatomical and biochemical changes in rice plant roots in response to seed treatment with rhizobacteria (Burkholderia pyrrocinia(R-46) +Pseudomonas fluorescens(R-55)) andTrichoderma asperellum(Ta: mixture of strains T-06, T-09, T-12, and T-52). The experimental design was completely randomized, with six treatments (R-46, R-55, R-46 + R-55, Ta+ R-46 + R-55, Ta, and control) and ten replicates. Treatments Ta and R-46 + R-55 increased the root length and diameter as well as the cortex expansion and induced a 2% expansion of the aerenchymal space. Treatments Ta and R-46 increased the vascular cylinder diameter. The number of protoxylem poles and metaxylem vessel elements was increased by R-46 and R-55. The total phenol content increased with treatments Ta, R-46 + R-55, R-46, and R-55, and all the treatments increased the flavonoid content. The lignin content increased with the Ta and R-55 treatments. All the root architecture modifications resulting from the interaction between seedlings and bioagents (rhizobacteria andTrichodermaspp.) observed in the present study favored the root plasticity of rice seedlings.

The authors have investigated the effects of different doses of mineral fertilizers combined with co-inoculation of Bacillus subtilis and Trichoderma asperellum to promote plant growth and use efficient nutrients in a plant Urochloa (Syn. Brachiaria) brizantha cv. Marandu. Individual experiments with doses of the nutrients nitrogen (N), phosphorus (P), and potassium (K) were carried out. The experiment was conducted in a completely randomized design, factorial 35. With the treatments: control noninoculation, inoculation with Bacillus subtilisUFRA-92, and coinoculation (MIX) with T. asperellum (UFRA-06, UFRA-09, UFRA-12, and UFRA-52)+B. subtilis x nutrient omissions (0, 25, 50, 75, and 100). Each treatment had five replications. Biometric parameters, nutrient content, and nutrient use efficiency were evaluated. The results showed that the inoculants promoted growth in Marandu grass. The use of inoculants promoted growth and increased N, P, and K uptake by Marandu grass. Co-inoculation changed leaf area, shoot length, elongation rate, and leaf appearance for N and K and root dry mass for P. In addition, the co-inoculation combined with doses of 75 of N, 50 of P, and 50 of K increased the nutritional content of the leaves by 256 of N, 280 of P, and 29 of K and provided greater agronomic efficiency, with increments of 462 of N, 544 of P, and 177 of K, compared to the control treatment. We present the potential of co-inoculation of B. subtilis and T. asperellum to promote the growth of Urochloa under reduced fertilizer application. There was an improvement in plant growth and nutrient use efficiency.