A new cyanobacterial species with a protective effect on lettuce grown under salinity stress: Envisaging sustainable agriculture practices

Abstract

In this work, a new terrestrial cyanobacterial species, Oculatella lusitanica LEGE 161147, was isolated and characterized using a polyphasic approach. Morphologically, O. lusitanica shares characteristics with different Oculatella species (mainly with O. crustae-formantes), lacking distinctive features. However, the phylogeny based on the 16S rRNA gene sequence and the 16S-23S ITS secondary structures support the establishment of this isolate as a new species. O. lusitanica is placed within a clade mainly composed by other Oculatella terrestrial strains; however, it forms a separate lineage. In addition, our species differs from the other Oculatella described so far by lacking the V2 helix within the ITS region. Since cyanobacteria are known to release compounds that promote plant growth and/or increase their tolerance to stresses, the effect of this newly described cyanobacterial species on Lactuca sativa (lettuce) plants development and salinity stress resistance was evaluated. Our results showed that, although the cyanobacterium had no impact on plant growth under the conditions tested, it was able to mitigate the deleterious salinity stress effects on plant size, root and aerial part fresh weight, by eliciting the non-enzymatic antioxidant response system (proline, H2O2 and reduced glutathione). In addition, the microorganism was able to induce a priming effect on lettuce plants by stimulating defensive mechanisms under non-stress conditions, and enhances the activity of nitrogen metabolism-related enzymes glutamate dehydrogenase, glutamine synthetase and nitrate reductase. These results indicate that this native terrestrial cyanobacterial species could be employed as a tool in sustainable agricultural practices.

Albertania and Egbenema gen. nov. from Nigeria and the United States, expanding biodiversity in the Oculatellaceae (cyanobacteria)

“…The type genus of the family, Oculatella , is mostly a soil genus (Becerra‐Absalón et al, 2020; Jung et al, 2020; Mikhailyuk et al, 2022; Osorio‐Santos et al, 2014; Vinogradova et al, 2017). Other taxa were found in subaerial habitats such as caves (Chakraborty et al, 2021; Zammit et al, 2012) or wet walls or hard man‐made substrates such as clay pots (Brito et al, 2022; Mai et al, 2018). A few taxa have been described from aquatic environments (Jahodářová, Dvořák, Hašler, Holušová, & Poulíčková, 2017; (Jahodářová, Dvořák, Hašler, & Poulíckova, 2017; Osorio‐Santos et al, 2014; Strunecký et al, 2020).…”

“…nuda, Til. torsiva, (Mai et al, 2018), and Oculatella lusitanica (Brito et al, 2022). Soils are similar to but harsher than subaerial habitats, yet they numerous species in the family Oculatellaceae, including, in the genus Oculatella, O.…”

Potential of microalgae and cyanobacteria to improve soil health and agricultural productivity: a critical view

“…Likewise, Naorem and Udayana 140 considered cyanobacteria as add-ons of the beneficial soil microbiota to remediate salt-affected soils under organic farming. In a recent report, Brito et al 141 showed that the soil application of a new terrestrial cyanobacterial species ( Oculatella lusitanica LEGE 161147) on lettuce ( Lactuca sativa L. cv Marvel of Four Seasons) had a limited priming effect. However, there were beneficial effects by mitigating the deleterious salinity stress by eliciting non-enzymatic antioxidant ( i.e.…”

Cyanobacteria as a Valuable Natural Resource for Improved Agriculture, Environment, and Plant Protection

“…Moreover, photosynthetic pigments, relative water, stability of membrane, carbohydrates, proline, ascorbic acid, glutathione, N, P, and K+ion content, superoxide dismutase, and catalase activities were also stimulated compared to control plants. Furthermore, Brito et al ( 2022 ) found that the cyanobacterial species Oculatella lusitanica LEGE stimulated salinity stress resistance in lettuce plants by increasing the non-enzymatic antioxidant system (H 2 O 2 , proline, and reduced glutathione). Regarding drought cases, soils inoculated by Spirulina meneghiniana and Anabaena oryzae improved lettuce plants’ growth as compared with non-inoculated soil plants (Ibraheem, 2007 ).…”