Plant growth-promoting bacteria improve Triticum aestivum L. growth and photosynthetic activity in sulfonamide-contaminated soil

Authors: AMMARA SALEEM, ASMA ZULFIQAR, SOHA A. ALAMOUDI, MADA F. ASHKAN, EMAN ALHOMAIDI

Abstract: Antibiotics are disseminated by grazing animals or their feces throughout agricultural areas. These antibiotics, as environmental pollutants, have a negative impact on plant growth and physiology. Sulfonamides are frequently used to protect livestock production, but they also have a considerable negative impact on plant growth and rhizospheric bacteria. Plants are sensitive to their surroundings, and they employ their internal biological systems to deal with the threats to their growth and development. Soil microbes, which are the most common inhabitants, have amazing metabolic capacities that enable them to overcome abiotic constraints. The effects of sulfonamide stress on wheat cultivar Chakwal-50 were studied in terms of morphological and biochemical processes, as well as stress mitigation by microorganisms isolated from wheat rhizospheric soil. This research looked at the effects of four new derived sulfonamides (SAs): 2-phenylsulfonyl hydrazine carbothioamide (TSBS-1), N,2-bis phenylhydrazine carbothioamide (TSBS-2), aminocarbonyl benzene sulfonamide (UBS-1), and N, N'-carboxyl dibenzene sulfonamide (UBS-2). Five rhizospheric bacterial strains were used: AC (Actinobacteria sp.), RS-3a (Bacillus sp.), RS-7a (Bacillus subtilis), RS-4a (Enterobacter sp.), and RS-5a (Enterobacter sp.). T. aestivum seeds were sterilized before being cultivated in soil polluted with various sulfonamide derivatives and inoculated with various bacterial strains under natural environmental conditions. To analyze the effect of sulfonamides on several aspects of plant growth, data from each antibiotic and bacterial strain was used to determine shoot fresh weight, root fresh weight, root and shoot length, number of leaves, and photosynthetic activity on the 15th day of germination. According to the results, Inoculation of Bacillus spp. (RS-3a) produced a maximum shoot fresh weight (FW) and shoot length by 8.14 g and 15.19 cm, respectively. Actinobacteria sp. (AC) had the highest chlorophyll value of 37 μg/g FW, while Bacillus spp. (RS-3a) increased carotenoid values with the average value of 550 μg/g FW by reducing sulfonamide stress. Following this preliminary screening, some bacterial strains were found to be promising plant growth promoting rhizobacteria for improving plant growth in a way that was both safe and effective.

Keywords: T. aestivum, growth parameters, sulfonamide stress, morphological parameters, total chlorophyll, carotenoid content

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