Genome sequence of Mangrove species

News: Scientists at the DBT-Institute of Life Sciences, Bhubaneswar and SRM-DBT Partnership Platform for Advanced Life Sciences Technologies, SRM Institute of Science and Technology, Tamil Nadu have reported for the first time a reference-grade whole genome sequence of a highly salt-tolerant and salt-secreting true-mangrove species, Avicennia marina.

Details:

  • Avicennia marinais one of the most prominent mangroves species found in all mangrove formations in India. It is a salt-secreting and extraordinarily salt-tolerant mangrove species that grows optimally in 75% seawater and tolerates >250% seawater.
  • It is among the rare plant species, which can excrete 40% of the salt through the salt glands in the leaves, besides its extraordinary capacity to exclude salt entry to the roots.
  • This study assumes significance as agriculture productivity globally is affected due to abiotic stress factors such as limited water availability and salinization of soil and water. Availability of water is a significant challenge to crop production in dryland areas, accounting for ~40 percent of the world’s total land area. Salinity, is prevalent in ~900 million hectares globally (with an estimated 6.73 million ha in India), and it is estimated to cause an annual loss of 27 billion USD.
  • The genomic resources generated in the study will pave the way for researchers to study the potential of the identified genes for developing drought and salinity tolerant varieties of important crop species of the coastal region that is significant for India with 7,500m of coastline and two major island systems.

What are Mangroves?

  • Mangroves are a special type of vegetation. And they are found in the intertidal regions where freshwater and saltwater intermix, in the bays, estuaries, creeks, and lagoons.
  • They are the salt-tolerant variety of plants, which can survive in harsh conditions. And they are economically and ecologically significant.
  • They represent the littoral forest ecosystem. Low lying areas of tropical and subtropical regions (Between 24 degrees North and 38 degrees South) are home to Mangroves
  • They are also called Halophytes – They are salt-tolerant.
  • The trees that grow in Mangrove Forests are generally 8-20 meters high. These trees have thick leaves.
  • They are confined to tropical and subtropical regions as they need high solar radiation to filter saline water through their roots. They have blind roots which are called Pneumatophores. These roots help these trees to respire in anaerobic soils.  The seeds of Mangrove Forests trees germinate in the trees itself before falling – This is called Viviparity mode of reproduction
  • Mangrove Forests trees project different types of roots:
    • Prop – They are down into the water
    • Air – They are vertically configured up from the mud
    • Stilt – These roots emerge from the main trunk of the tree; also called adventitious roots
  • There are types of Mangroves:
    • Red – Found along the coastlines
    • Black – Major feature of such mangrove trees is their dark bark. They have access to more oxygen.
    • White – Compared to Red and Black mangroves; they grow at the highest elevation.
  • The major mangroves in India are found at:
    • Sundarban Groves
    • Mahanadi Mangroves
    • Krishna Godavari Mangroves
    • Mangroves of Gujarat
    • Ratnagiri Mangroves
    • Goa Mangroves
    • Cauvery Deltaic Mangroves
    • Krishan-Godavari Mangroves
    • Andaman Nicobar Mangroves