Unveiling novel genes in Fern genomes for the design of stress tolerant crops

Ferns are the second largest vascular plant lineage after angiosperms, shaping the plant biodiversity on our planet for more than 360 million years. Understanding the biological function of fern genes and their potential uses for agriculture, environment and health has been hampered by the lack of high-quality genome sequence of fern. The last five years have seen the assembly of reference fern genomes of Salvinia cucullata (0.26 ​Gb, n ​= ​9), Azolla filiculoides (0.75 ​Gb, n ​= ​22), Adiantum capillus-veneris (4.83 ​Gb, n ​= ​30), Alsophila spinulosa (6.27 ​Gb, n ​= ​69) and Ceratopteris richardii (7.46 ​Gb, n ​= ​39). These high-quality genome sequences will make significant contribution to the better understanding of evolution, ecology, functional genomics, and the diverse applications of ferns. Here, I review the physiological and some aspects of limited molecular mechanisms of abiotic (mainly heavy metal, drought, and shade) and biotic (pests and pathogens) tolerance in different fern species. The potential use of the fern genome toward crop abiotic and biotic stress tolerance is suggested. Thus, deciphering the genetic diversity and novel functional genes of ferns will provide tremendous boost to the knowledge advancement and the biotechnological applications of unique fern genes and proteins for sustainable agricultural production and environmental protection.