Raising Beet Tolerance to Salinity through Bioaugmentation with Halotolerant Endophytes

• Main Authors: Sonia Szymańska, Jarosław Tyburski, Agnieszka Piernik, Marcin Sikora, Justyna Mazur, Hrynkiewicz Katarzyna
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Agronomy
• Subjects: PGPE—plant growth-promoting endophyte; salt stress; <i>Beta vulgaris</i>; <i>Kushneria marisflavi</i>; <i>Pseudomonas stutzeri</i>
• Online Access: https://www.mdpi.com/2073-4395/10/10/1571

Increasing land salinization in recent decades has led to a decrease in crop productivity worldwide. We hypothesized that bioaugmentation of beetroot (<i>Beta vulgaris</i>) with halotolerant endophytic bacterial strains isolated from the obligatory halophytic plant <i>Salicornia europaea</i> L. may mitigate salt stress in new host plants. Therefore, we investigated the effects of inoculation with <i>Pseudomonas stutzeri</i> ISE12 or <i>Kushneria marisflavi</i> CSE9 on <i>B. vulgaris</i> growth in substrates enriched with various NaCl concentrations (0, 50, 150, 300 mM). The results of this study indicated that bioaugmentation with either bacteria resulted in improved growth parameters and increased chlorophyll content, as well as decreased proline and hydrogen peroxide concentrations, in <i>B. vulgaris</i> organs. However, <i>K. marisflavi</i> CSE9 was more efficient in achieving salt stress mitigation than <i>P. stutzeri</i> ISE12. In conclusion, the range of salinity tolerance seems to be a key parameter in the selection of strains for beet inoculation. The selected halotolerant endophytes (<i>P. stutzeri</i> ISE12 and <i>K. marisflavi</i> CSE9) isolated from the roots of obligatory halophytic <i>S. europaea</i> may be employed for plant growth promotion, especially in saline areas, and have potential applications in sustainable agriculture.