Modeling photosynthetic resource allocation connects physiology with evolutionary environments.

Area of Science:

• Plant Physiology
• Evolutionary Biology
• Biomathematics

Background:

• Biological resource allocation is shaped by natural selection across ancestral and current environments.
• Understanding the balance between adaptation to past versus present conditions is crucial for plant science.

Purpose of the Study:

• To investigate the extent to which resource allocation patterns in C3, C4, and C3-C4 intermediate plants (Flaveria genus) are adapted to current conditions versus ancestral environments.
• To quantify the impact of environmental factors and evolutionary history on photosynthetic resource allocation and plant performance.

Main Methods:

• Development of a detailed mathematical model of carbon fixation, incorporating environmental parameters and energy/nitrogen partitioning.
• Assessment of environment-dependent plant physiology and performance based on resource allocation patterns.
• Comparison of model performance for C4 plants optimized for ancestral versus experimental growth conditions.

Main Results:

• Models of C4 plants optimized for ancestral conditions outperformed those for experimental conditions, suggesting limited phenotypic plasticity.
• The model predicts C4 species require greater nitrogen reallocation between photosynthetic components than C3 species to adapt to new environments.
• Resource distribution patterns in C4 plants appear to reflect optimality in ancestral environments.

Conclusions:

• Observed resource allocation patterns in C4 plants may still reflect optimality in ancestral environments, offering a way to infer past environmental conditions.
• C4 plants exhibit lower phenotypic plasticity compared to C3 plants, indicating a potential constraint in adapting to rapidly changing environments.
• This study quantifies the interplay between evolutionary history and environmental influences on photosynthetic resource allocation.