Genes responsible for long lifespan of banyan, peepal trees identified

Genes responsible for long lifespan of banyan, peepal trees identified

Subject : Science and Technology

Context:

• Researchers at the Indian Institute of Science Education and Research (IISER) Bhopal have carried out whole genome sequencing of banyan ( Ficus benghalensis) and peepal ( Ficus religiosa) from leaf tissue samples. They also undertook a comprehensive genome-wide phylogenetic analysis with 50 other angiosperm plant species, including four other sequenced Ficus species.

Research analysis:

• 17 genes of the Banyan tree and 19 genes of the peepal tree have been identified.
• These genes are having multiple signs of adaptive evolution (MSA) that plays a pivotal role in the long-term survival of these two Ficus species.
• The genes with MSA came about in response to the population bottleneck faced by both trees around 0.8 million years ago.
  • Genes showing multiple signs of adaptive evolution in banyans were mainly associated with root development, leaf formation, metabolism, pollen tube and seed development and other developmental processes.
  • The MSA genes of peepal trees were mainly associated with root development, reproduction, and metabolism.
• The comparative evolutionary analysis performed across 20 phylogenetically closer  Eudicot species revealed adaptive evolution in genes involved in major cellular mechanisms associated with long-time survival such as phytohormones signalling, senescence pathways, fig-wasp coevolution, and stress tolerance.
• Gene family expansion/contraction analysis revealed that the highly expanded gene families of both species were involved in disease resistance functions in plants.
• In the case of the banyan tree, 15 of 17 MSA genes were also associated with tolerance against environmental stress — drought, oxidative stress, and pathogens. In peepal trees, 17 out of 19 MSA genes were associated with stress tolerance activities.
  • Stress tolerance mechanisms are also responsible for the medicinal properties of these trees.
• In addition, the researchers identified seven genes involved in two pathways that produce volatile organic compounds in floral scents which attract wasps for pollination.