Crop improvement using hornwort genomeDate: 17 March 2020 Tags: Miscellaneous
An international team has sequenced three hornwort genomes, providing insights into the genetics underlying the unique biology of the group, a representative of the earliest land plants.
Some 500 million years ago, when our continents were connected in a single land mass and most life existed underwater, hornworts (Anthoceros) were one of the first groups of plants to colonize land.
One of the researchers' goals was to find genes that play a role in hornworts' method of concentrating carbon dioxide inside chloroplasts, which boosts the plants' ability to make sugar resulting in increased yield.
Hornworts are unique among land plants in this capability, but some species of algae share the trait. The researchers thus compared the hornwort genomes with those of algae and found one gene, LCIB, that is shared by the two groups of plants but not with other land plants.
If this carbon-concentrating mechanism could be installed in crop plants, then they could grow larger with the same amount of fertilizer.
Hornworts live in symbiosis with fungi and cyanobacteria providing phosphorus and nitrogen to the plant. The researchers also identified 40 genes that may promote the hornworts' source of nitrogen, which comes from an interdependent relationship with cyanobacteria - a unique feature in land plants.
If this capability of hornworts can be transferred to crop plants, many tons of nitrogen fertilizer could be saved. Such a reduction in fertilizer could benefit the environment, since excess agricultural nitrogen frequently enters waterways, where it can cause deadly algal blooms.
Hornworts, liverworts and mosses were among the first plants to colonize land, but how the three groups were related had previously not been clear. The research shows clearly that hornworts, liverworts and mosses are all more closely related to each other than they are to vascular plants.