Journal of Tropical Oceanography ›› 2023, Vol. 42 ›› Issue (6): 89-100.doi: 10.11978/2023036CSTR: 32234.14.2023036

• Marine Biology • Previous Articles     Next Articles

Adaptive mechanisms of iron limitation on the marine Synechococcus based on comparative genomics

MU Rong(), ZHU Zhu(), ZHANG Ruifeng   

  1. School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
  • Received:2023-03-23 Revised:2023-04-28 Online:2023-11-10 Published:2023-11-28
  • Supported by:
    National Natural Science Foundation of China(41890801); International Cooperation in Science and Technology Innovation between Governments(2022YFE0136500)

Abstract:

Low solubility and limited source of iron in seawater are the main growth limiting factors for phytoplankton in 40%of the global ocean. Marine Synechococcus is a picocyanobacteria with global distribution and is one of the most important contributors to marine prime productivity. Affected by the source and concentration of iron in coastal and oceanic environments, marine Synechococcus has different adaptive mechanisms to iron limitation. In this study, we performed a comparative genomic analysis of 29 whole genome sequenced marine Synechococcus. The results showed that marine Synechococcus had high genetic diversity and belonged to four genera of Cyanobiaceae under the GTDB (Genome Taxonomy Database) taxonomy, and these four genera corresponded well to the subtype under NCBI (National Center for Biotechnology Information) taxonomy. The results of functional annotation showed that the number and types of unique genes differed between coastal and oceanic Synechococcus, and unique gene of coastal strains are more involved in inorganic ion transport and metabolism. Further analysis of iron limitation-related genes in marine Synechococcus revealed that the coastal strain had stronger abilities of iron uptake, homeostasis regulation and storage than the oceanic strains, and had a better ability to sense and respond to environmental changes. In this study, we reviewed the evolutionary relationships and taxonomic positions of marine Synechococcus using comparative genomics, and identified the differences in the genome and adaptive mechanisms of coastal and oceanic strains in response to iron limitation, to provide a basis for better understanding of the environmental adaptation of marine Synechococcus.

Key words: Comparative genomics, marine Synechococcus, iron limitation, adaptive mechanisms