Relationships between protein-encoding gene abundance and corresponding process are commonly assumed yet rarely...

Area of Science:

• Microbiology
• Ecology
• Genomics

Background:

• Enzyme-catalyzed reactions require specific genes and transcripts.
• A direct relationship between gene/transcript abundance and process rates is commonly assumed in ecological studies.
• Understanding this relationship is crucial for interpreting 'omics' data in environmental contexts.

Purpose of the Study:

• To meta-analytically assess the relationship between gene/transcript abundance and corresponding ecosystem process rates.
• To investigate if factors like habitat type or gene characteristics influence this relationship.
• To identify knowledge gaps in linking molecular data to ecosystem functions.

Main Methods:

• Conducted a meta-analysis of published studies.
• Identified studies quantifying gene/transcript abundance for carbon or nitrogen cycling enzymes.
• Extracted data on both molecular abundance and process rates from 59 relevant studies.

Main Results:

• A significant but weak positive correlation was found between gene abundance and process rates within studies.
• Accounting for habitat type, gene differences, or reaction components did not strengthen the correlation.
• A large proportion of studies (415 identified, 59 used) lacked paired molecular and process rate data.

Conclusions:

• The assumed direct link between gene/transcript abundance and ecosystem process rates is only weakly supported.
• Ecological and methodological factors likely mediate the relationship between molecular data and ecosystem functions.
• Further research is needed on transcription, translation, and enzyme kinetics in natural environments to bridge the 'omics' to ecosystem process gap.