Patterns and evolution of ACGT repeat cis-element landscape across four plant genomes

Area of Science:

• Plant molecular biology
• Genomics
• Bioinformatics

Background:

• Transcription factor binding is crucial for gene regulation, with cis-elements like ACGT motifs playing a key role.
• Specificity is maintained by sequence, inter-motif distance, and spacer characteristics.
• ACGT elements are important cis-elements that often regulate gene expression synergistically.

Purpose of the Study:

• To analyze the conservation of co-occurring ACGT core elements in plant promoters across monocot and dicot species.
• To investigate the relationship between spacer distance and ACGT element conservation.
• To identify conserved spacer regions and regulatory conditions for promoters with multiple ACGT elements.

Main Methods:

• Comparative analysis of ACGT element distribution and spacer lengths in promoters of *Oryza sativa*, *Sorghum bicolor*, *Arabidopsis thaliana*, and *Glycine max*.
• Identification of conserved spacer regions and sequence preferences using data from *A. thaliana* and *O. sativa*.
• Correlation of ACGT element patterns with gene expression data, particularly in response to stress.

Main Results:

• Specific predominant spacer lengths were observed between co-occurring ACGT elements, though not universally conserved across species.
• Local regions of high correlation in spacer lengths were found among monocots and dicots.
• A preference for G at the start and C at the end of spacer sequences was identified, indicating the prevalence of the G-box motif.
• Co-occurring ACGT elements were linked to gene regulation in response to exogenous stress.
• Conservation of ACGT (N) ACGT patterns in orthologous genes suggests parallel evolution of these cis-elements.

Conclusions:

• This is the first study comparing ACGT element occurrence and conservation across four plant species.
• Preferred spacer distances suggest potential roles in unidentified physiological functions.
• Variations in correlation patterns between monocots and dicots may reflect differences in transcriptional regulation.
• Co-occurring ACGT elements are involved in stress responses, with regulation varying based on ACGT (N) ACGT motif.
• Findings provide a resource for optimizing spacer length and sequence in promoter design.