From Antarctic DNA to stress tolerant crop plants – exploiting the why protein domain

Abstract

Screening of an Antarctic soil functional fosmid metagenomic library identified a novel bacterial gene, homologous to known Water Hypersensitivity (WHy) domains. The WHy domain is a typical component of Late Embryogenesis Abundant (LEA) proteins which occurs widely in both prokaryotes and in plant eukaryotes and are expressed under various stress conditions [1]. A phylogenetic analysis of multiple WHy homologues from different species suggested that the ancestral origin of this protein gene lies within the ancient archaea [1]. Our previous studies have shown that this bacterial protein elicits significant protection against freeze and cold stress in recombinant E. coli [2]. Expression of the WHy gene in Arabidopsis resulted in a wide range of statistically significant stress-tolerant phenotypic properties. These included an increase of up to 6-fold higher germination efficiency of transgenic recombinant seeds compared to the WT, and a 100 % survival rate of WHy gene-expressing plants compared to 0 % survival of adult WT plants after freeze shock. Similar improvements in survival rates were observed for recombinant plants in drought stress experiments. References Mertens J, Aliyu H, Cowan DA (2018). Applied and environmental microbiology, AEM-00539. Anderson D, Ferreras E, Trindade M, Cowan D (2015). FEMS Microbiology Letters, 362(15):fnv110.