Understanding the role(s) of the ABI3 transcription factor in vegetative desiccation tolerance towards the development of downstream applications
Abstract
Vegetative desiccation tolerance is a rare phenomenon, appearing in phylogenetically distant lineages, implying multiple independent evolutionary origins. According to transcriptomic studies, there are seed related genes that are activated in leaf tissues during water shortage stress in desiccation tolerant angiosperms, although many of these genes are also substantially expressed in desiccation-sensitive species during water-deficit stress response. Abscisic acid insensitive 3 (ABI3) is a well-known transcription factor has been shown to play a critical role in seed desiccation tolerance (DT) in Arabidopsis thaliana. ABI3 expression is induced by drought stress in Arabidopsis thaliana, and it activates the expression of downstream genes that are involved in stress response. Overexpression of ABI3 has been shown to increase drought tolerance in Arabidopsis, suggesting that ABI3 is a key regulator of this trait. The role of ABI3 in vegetative desiccation tolerance is still being elucidated, but it is certain that ABI3 plays a critical role in this process. In this research study, the AB13 1kb promoter was compared against other transcription factors such as FUSCA3, RAV1 and ABF1 (all known to play a role in DT) by comparative bioinformatics, involving the use of Galaxy Bioinformatics for database creation, NCBI BLAST and PLACE promoter analysis. The aim was to specifically target the Cis-Regulatory Elements that are involved in DT. Cis-Regulatory Elements are small coding regions of DNA that code for different response type elements such as drought and water stress, temperature stress and photosynthesis. Several Cis-Regulatory Elements were identified; LTRECOREATCOR15, PRECONSCRHSP70A, ACGTATERD1 and PROLAMINBOXOSGLUB1, all of which are thought to play a critical role of activating genes that are directly involved in seed and vegetative desiccation tolerance. Understanding the role of ABI3 in vegetative desiccation tolerance will provide new insights into the mechanisms of drought tolerance and will contribute to the development of downstream applications to improve crop performance under drought conditions. The flipping of gene switches could help engineer agricultural crops that can survive harsh droughts with very little rainfall. The creation of a resurrection phenotype in crops will allow agriculture to expand.