Phosphoribosylpyrophosphate synthetase as a metabolic valve advances Methylobacterium/Methylorubrum phyllosphere colonization and plant growth.

The proficiency of phyllosphere microbiomes in efficiently utilizing plant-provided nutrients is pivotal for their successful colonization of plants. The methylotrophic capabilities of Methylobacterium/Methylorubrum play a crucial role in this process. However, the precise mechanisms facilitating efficient colonization remain elusive. In the present study, we investigate the significance of methanol assimilation in shaping the success of mutualistic relationships between methylotrophs and plants. A set of strains originating from Methylorubrum extorquens AM1 are subjected to evolutionary pressures to thrive under low methanol conditions. A mutation in the phosphoribosylpyrophosphate synthetase gene is identified, which converts it into a metabolic valve. This valve redirects limited C1-carbon resources towards the synthesis of biomass by up-regulating a non-essential phosphoketolase pathway. These newly acquired bacterial traits demonstrate superior colonization capabilities, even at low abundance, leading to increased growth of inoculated plants. This function is prevalent in Methylobacterium/Methylorubrum strains. In summary, our findings offer insights that could guide the selection of Methylobacterium/Methylorubrum strains for advantageous agricultural applications.

Evaluation of the Two Typical Diamide Insecticide-Induced Oxidative Damages and the Molecular Mechanism Underlying Their Toxicity in Triticum aestivum.

As the typical representatives of diamide insecticides, excessive exposure to flubendiamide and chlorantraniliprole for plants may inevitably pose threats to plant growth and food safety. However, the underlying toxic mechanisms remain unclear. Here, glutathione S-transferase Phi1 from Triticum aestivum was employed as the biomarker to assess oxidative damages. First, flubendiamide displayed much stronger binding affinity with TaGSTF1 than chlorantraniliprole in consistent with molecular docking results, and flubendiamide also exerted more evident effects on the structure of TaGSTF1. Then, glutathione S-transferase activities of TaGSTF1 declined after interaction with these two insecticides, especially for flubendiamide with more hazardous influence. At last, the adverse impacts on the germination and growth of wheat seedlings were further evaluated with more apparent inhibition of flubendiamide. Hence, this study may illustrate the detailed binding mechanisms of TaGSTF1 with these two typical insecticides, evaluate the destructive impacts on plant growth, and further assess the threat to agriculture.