ACC Deaminase Producing Methylobacterium oryzae CBMB20 and Exogenous Trehalose Application Alleviate Salinity Stress in Arabidopsis

Abstract

Farming communities are very concerned about salt stress because of its negative impact on crop productivity. This study evaluated the ability of the Methylobacterium oryzae CBMB20 and exogenous trehalose treatments on Arabidopsis thaliana growth under salt stress conditions. A. thaliana growth was enhanced using M. oryzae CBMB20 as a bioinoculant in both saline and nonsaline environments. In addition to better photosynthetic efficiency and endogenous trehalose content, the inoculation of M. oryzae CBMB20 produced improved growth parameters, such as increased rosette fresh weight and shoot length. Reduced levels of proline and malondialdehyde (MDA) under salt stress (150 mM NaCl) further indicated that the inoculated plants had enhanced tolerance to salinity. GFP-tagged M. oryzae CBMB20 was also used in spatial distribution experiments, which showed that the bacteria colonized A. thaliana's root, shoot, and hypocotyl. By increasing shoot length and total fresh weight, the exogenous application of trehalose also markedly enhanced plant growth. Proline and MDA contents were decreased by exogenous trehalose during salt stress, while the endogenous trehalose concentration in A. thaliana remained unaffected. The use of trehalose and M. oryzae CBMB20 can both have a good impact on plant development and stress tolerance in saline environments.