Cell-free supernatant of Devosia sp. (strain SL43) mitigates the adverse effects of salt stress on soybean (Glycine max L.) seed vigor index

Abstract

Soil salinity is a major constraint for soybean production worldwide, and the exploitation of plant growth-promoting bacteria (PGPB) and their bioactive metabolite(s) can improve plant salinity tolerance. With this objective, two experiments were performed, aiming to test 4 culture media (YEM(A), TYE(A), TS(A), and LB(A)) for growing a novel Devosia sp. (strain SL43), and then evaluating cell-free supernatants (CFS) from the Devosia sp. on germination of soybean (Glycine max L.) seeds under salinity stress. Soybean seeds were subjected to three salinity levels (0, 100, and 125 mM NaCl) and 6 levels of Devosia sp. CFS dilution (0, 1:1, 1:100, 1:250, 1:500, 1:1000). The results indicated that 125 mM NaCl concentration caused the greatest reduction in the total number of germinated seeds (15%), germination rate (43.6%), root length (55.2%), root weight (39.3%), and seed vigor (68%), and it also increased mean germination time by 71.9%. However, Devosia-CFS improved soybean germination, and the greatest effect was obtained at 1:1 dilution. Under the highest salinity level, application of CFS at 1:1 dilution increased final germination (17.6%), germination rate (18.6%), root length (162.2%), root weight (239.4%), seed vigor index (318.7%), and also shortening mean germination time by 19.2%. The results indicated that seed vigor index was positively correlated with other traits except for mean germination time. Our study suggested that the highest productivity of Devoisa sp. was obtained from the YEM medium. Results also suggested that CFS produced by the novel Devosia sp. (SL43 strain) can successfully alleviate salt stress effects on soybean seed germination and manipulating the chemical composition of the growth medium can influence the effectiveness of these bioactive metabolites.

Differential Impacts of Road De-icers on Freshwater Bacterial Communities

“…The relative abundance of Devosia, another Gram− bacterium, was also increased in the HM samples, with members of this taxon known to tolerate brackish conditions [70]. Devosia can be associated with green algae which is consistent with its increased abundance as the chl a levels increased 3.4-fold, serving as a diazotroph by fixing nitrogen, but it can also facilitate the maintenance of ion homeostasis, which may be significant in the mixed salts of the "eco-friendly" de-icer [71,72]. Since members of Devosia can be halophilic and this genus was found at the highest relative abundance in the HM samples, we cannot exclude that it too was a contaminant in the M de-icer formulation.…”

Regulation of Photosynthetic Capacity and Ion Metabolism of Oilseed Rape under Salt Stress by Prohexadione-Calcium Priming

“…Studies have concluded that germination index, vigor index, and seedling fresh weight can be used as effective indicators for screening salt tolerance in oilseed rape at the germination stage [26]. Some scholars have found that sorghum seed shoot length, root length, germination potential, and germination rate showed a sequential decrease with increasing salt concentration and different degrees of delayed germination [27]. The results of the present study were similar to it; with increasing salt concentration germination index and vigor index continued to decline, and the average germination time increased, inhibiting the vigor of oilseed rape seeds and weakening the germination ability (Figure 1).…”