Citrus Genotype Modulates Rhizosphere Microbiome Structure and Function Under Drought Stress

Area of Science:

• Plant Science
• Microbiology
• Soil Science

Background:

• Drought stress negatively impacts citrus growth and alters soil microbial communities.
• The specific role of these microbes in plant drought tolerance is not well understood.

Purpose of the Study:

• Investigate rhizosphere microbial structure, soil enzyme activities, and physicochemical properties in drought-tolerant (DR) and drought-sensitive (DS) citrus under drought.
• Determine how microbial communities contribute to citrus drought tolerance.

Main Methods:

• Utilized high-throughput sequencing to analyze rhizosphere microbial communities.
• Assessed soil enzymatic activities (catalase, urease, acid phosphatase) and physicochemical properties.
• Performed correlation analyses between microbial shifts and soil nutrient availability.

Main Results:

• Drought significantly altered microbial composition, reducing bacterial diversity and enriching stress-tolerant/pathogenic bacteria and fungi.
• The DR variety showed a more stable bacterial network with beneficial fungi (Penicillium, Trichoderma) and mycorrhizal fungi enrichment.
• Soil catalase and urease decreased, while acid phosphatase increased significantly in DR under drought.

Conclusions:

• Citrus drought tolerance is linked to a more resilient and cooperative rhizosphere microbiome.
• Host-specific microbial recruitment plays a critical role in plant adaptation to drought stress.
• Findings support the use of microbiome modulation for sustainable agriculture and crop resilience.