Bacillus subtilis var. natto promotes tobacco plant growth under normal conditions and in the presence of sodium bicarbonate

Abstract

The coastal areas of western Taiwan feature acidic and saline soils with low fertility. Sodium bicarbonate (NaHCO3), produced readily by carbon capture and storage technologies, could be suitable for the neutralization of acidic soils, but its effects on plant growth and the ability of Bacillus subtilis var. natto to confer salinity tolerance remain unclear. In this study, we examined the potential of sodium bicarbonate and B. subtilis var. natto (NTU18) to improve the growth of tobacco (Nicotiana tabacum L.) under salt stress conditions. We found that salt stress was the main factor affecting tobacco growth, resulting in shorter roots and shoots, a reduced leaf area and leaf number, and clustered dark green leaves. The addition of sodium bicarbonate exacerbated the symptoms of salinity stress. Inoculating the soil with B. subtilis did not enhance salinity tolerance, but intriguingly it increased shoot and root growth under normal conditions and in the presence of sodium bicarbonate. The mechanism of growth promotion mediated by the bacteria is unknown and should be investigated in more detail.

Keywords

• acidic soil
• bacillus subtilis var. natto
• nicotiana tabacum
• saline soil
• sodium bicarbonate