A unique, hereditary symbiosis exists between the water fern Azolla and cyanobacteria that reside within a cavity in the dorsal leaf-lobe of the plant. This association has been studied extensively, and questions have frequently been raised regarding the number and diversity of cyanobionts (cyanobacterial symbionts) among the different Azolla strains and species. In this work, denaturating gradient gel electrophoresis (DGGE) and a clone library based on the 16S rRNA gene were used to study the genetic diversity and host specificity of the cyanobionts in 35 Azolla strains covering a wide taxonomic and geographic range. DNA was extracted directly from the cyanobacterial packets, isolated after enzymatic digestion of the Azolla leaves. Our results indicated the existence of different cyanobiont strains among Azolla species, and diversity within a single Azolla species, independent of the geographic origin of the host. Furthermore, the cyanobiont exhibited host-species specificity and showed most divergence between the two sections of genus Azolla, Azolla and Rhizosperma. These findings are in agreement with the recent redefinition of the taxon Azolla cristata within the section Azolla. With regard to the taxonomic status of the cyanobiont, the genus Anabaena of the Nostocaceae family was identified as the closest relative by this work.
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http://dx.doi.org/10.1111/j.1529-8817.2007.00448.x | DOI Listing |
Front Plant Sci
December 2024
Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, India.
Maize ( L.) is an important cereal crop grown in arid and semiarid regions of the world. During the reproductive phase, it is more frequently exposed to drought stress, resulting in lower grain yield due to oxidative damage.
View Article and Find Full Text PDFHeliyon
October 2024
School of Environment, College of Engineering, Faculty of Environment, University of Tehran, P.O. Box 14155-6135, Tehran, Iran.
In today's world, environmental concerns about plastic pollution of aquatic and terrestrial ecosystems are at the forefront of many conversations. However, a solution that is gaining momentum is bioplastics. Bioplastics come from sustainable biological sources such as plants, bio-waste, or microorganisms, rather than non-renewable fossil fuels like petroleum or natural gas.
View Article and Find Full Text PDFHeliyon
October 2024
School of Plant and Horticultural Science, Hawassa University, Ethiopia.
Environ Sci Pollut Res Int
December 2024
School of Quantitative Sciences, Universiti Utara Malaysia, 06010, Sintok, Kedah, Malaysia.
The potential of two different aquatic macrophytes, Azolla pinnata R.Br. and Lemna minor L.
View Article and Find Full Text PDFEcotoxicology
November 2024
Federal University of São Carlos, Araras, São Paulo State, Brazil.
Long-residual herbicides can negatively impact aquatic ecosystems through surface runoff and leaching. This study evaluated the acute toxicity of indaziflam, sulfentrazone, clomazone, and tebuthiuron on Lemna minor and Azolla caroliniana. Experiments were conducted in the laboratory using a completely randomized design (CRD) with six concentrations of each herbicide across four replicates.
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