Multiple variation patterns of terpene synthases in 26 maize genomes

Area of Science:

• Plant Molecular Biology
• Genomics
• Biochemistry

Background:

• Terpenoids are crucial for plant defense against pests and herbivores.
• Terpene synthases (TPS) are key enzymes in terpenoid biosynthesis.
• Understanding TPS gene families in maize is vital for crop improvement.

Purpose of the Study:

• To identify and characterize terpene synthase (TPS) genes in a maize pan-genome.
• To investigate the evolutionary dynamics and expression patterns of TPS genes.
• To assess the impact of structural variations on TPS gene function and expression.

Main Methods:

• Pan-genome analysis of 26 high-quality maize genomes.
• Ka/Ks value evaluation to assess selection pressures.
• Analysis of RNA-sequencing data from maize under pest attack (Ostrinia furnacalis).
• Identification and characterization of structural variations (SV) affecting TPS genes.

Main Results:

• Identified 31 TPS genes, categorized as core, dispensable, near-core, and private.
• TPS25 exhibited positive selection in some varieties; six ZmTPS genes underwent purifying selection.
• Significant differences in ZmTPS25 expression were observed between genes with and without SV.
• Ten differentially expressed ZmTPS genes were identified in response to Ostrinia furnacalis feeding, with 9 being core genes.
• Many atypical TPS genes, affected by SV, were found across different maize genomes.

Conclusions:

• The study provides a comprehensive catalog of maize TPS genes and their genomic distribution.
• Structural variations significantly influence TPS gene structure and expression, potentially affecting plant defense.
• These findings offer valuable insights into the functional diversity of ZmTPS genes and their role in pest resistance.