Intraspecific plant-soil feedbacks alter root traits in a perennial grass

Area of Science:

• Plant-soil interactions
• Plant genetics
• Microbiome research
• Climate change adaptation

Background:

• Drought is a significant environmental stressor for plants and their associated microbiomes.
• Climate change is projected to increase the frequency and severity of drought events.
• Plant genomes can adapt to long-term drought, leading to genetic variation in drought tolerance.

Purpose of the Study:

• To investigate if genetic changes in plants due to drought affect rhizosphere microbial colonization patterns.
• To determine if these microbial changes feedback to influence plant drought responses.
• To test the hypothesis that plant genetic variation influences plant-soil feedback under drought.

Main Methods:

• Utilized 33 rhizosphere soils conditioned by 33 genotypes of *Tripsacum dactyloides* (eastern gamagrass) from native populations across a precipitation gradient.
• Conducted a fully factorial experiment using these soils as inocula to test plant responses under drought and well-watered conditions.
• Assessed variation in aboveground (shoot length, weight) and belowground (root anatomy, architecture) traits, and aerenchyma area.

Main Results:

• Watering treatment primarily affected aboveground plant traits.
• Belowground root traits were more influenced by the conditioning plant genotype.
• Aerenchyma area showed an interaction effect between watering treatment and conditioning plant genotype; both factors altered plant physiology and microbiome.

Conclusions:

• Plant genetic variation influences rhizosphere microbiome composition and plant-soil feedback dynamics.
• Intraspecies plant-soil feedback, driven by local adaptation, is critical for predicting plant responses to climate change.
• Understanding these dynamics is essential for effective restoration and agricultural strategies in changing climates.