Plant Beneficial Deep-Sea Actinobacterium, Dermacoccus abyssi MT1.1T Promote Growth of Tomato (Solanum lycopersicum) under Salinity Stress Rangseekaew, Pharada Barros Rodríguez, Adoración Manzanera Ruiz, Maximino Enrique Dermacoccus abyssi Marine actinobacteria Plant growth promoting actinobacteria Plant growth promoting actinomycetes Genomic analysis Salt tolerance Salinity stress Biosafety Sustainable agriculture Bioinoculants This research study was funded by the Spanish Ministry for Economy and Competitiveness and the European Union, within the context of the research project CGL2017-91737-EXP and by the Andalusian Regional Government and the European Union (research project P18-RT-976) and by the European Union through the Erasmus+ program and partially supported by Chiang Mai University. PR is grateful to the Graduate School, Chiang Mai University, for the TA/RA scholarship for 2019-2021. Salt stress is a serious agricultural problem threatens plant growth and development resulted in productivity loss and global food security concerns. Salt tolerant plant growth promoting actinobacteria, especially deep-sea actinobacteria are an alternative strategy to mitigate deleterious effects of salt stress. In this study, we aimed to investigate the potential of deep-sea Dermacoccus abyssi MT1.1T to mitigate salt stress in tomato seedlings and identified genes related to plant growth promotion and salt stress mitigation. D. abyssi MT1.1T exhibited plant growth promoting traits namely indole-3-acetic acid (IAA) and siderophore production and phosphate solubilization under 0, 150, 300, and 450 mM NaCl in vitro. Inoculation of D. abyssi MT1.1T improved tomato seedlings growth in terms of shoot length and dry weight compared with non-inoculated seedlings under 150 mM NaCl. In addition, increased total soluble sugar and total chlorophyll content and decreased hydrogen peroxide content were observed in tomato inoculated with D. abyssi MT1.1T. These results suggested that this strain mitigated salt stress in tomatoes via osmoregulation by accumulation of soluble sugars and H2O2 scavenging activity. Genome analysis data supported plant growth promoting and salt stress mitigation potential of D. abyssi MT1.1T. Survival and colonization of D. abyssi MT1.1T were observed in roots of inoculated tomato seedlings. Biosafety testing on D. abyssi MT1.1T and in silico analysis of its whole genome sequence revealed no evidence of its pathogenicity. Our results demonstrate the potential of deep-sea D. abyssi MT1.1T to mitigate salt stress in tomato seedlings and as a candidate of eco-friendly bio-inoculants for sustainable agriculture. 2022-04-18T09:14:23Z 2022-04-18T09:14:23Z 2022-01-26 info:eu-repo/semantics/article Rangseekaew, P... [et al.]. Plant Beneficial Deep-Sea Actinobacterium, Dermacoccus abyssi MT1.1T Promote Growth of Tomato (Solanum lycopersicum) under Salinity Stress. Biology 2022, 11, 191. [https://doi.org/10.3390/biology11020191] http://hdl.handle.net/10481/74315 10.3390/biology11020191 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI