Phyllosphere Keystone Beneficial Specialists Enhance Yield in Nutrient Deficiency-Resistant Sorghum Cultivars

Area of Science:

• Plant Science
• Microbiology
• Agronomy

Background:

• The phyllosphere (plant leaf surface) microbiome is crucial for crop productivity but remains understudied compared to root and soil microbiomes.
• Understanding host genotype's role in shaping phyllosphere microbial communities is vital for sustainable agriculture.

Purpose of the Study:

• To investigate how sorghum (Sorghum bicolor) host genotype mediates phyllosphere microbial community assembly, keystone taxa enrichment, and crop yield.
• To identify specific microbial groups associated with nutrient deficiency resistance and their correlation with yield outcomes.

Main Methods:

• Comparative analysis of phyllosphere microbiomes from sorghum cultivars resistant and susceptible to nutrient deficiency under field conditions.
• Assessment of microbial community structure (β-diversity), co-occurrence networks, and abundance of keystone beneficial specialists (KBS).
• Structural equation modeling to elucidate the interplay between soil properties, KBS, host genotype, and yield.

Main Results:

• Significant differences in phyllosphere microbiome β-diversity were observed between resistant and susceptible sorghum cultivars.
• Resistant cultivars exhibited more modular microbial networks enriched in KBS (Bacteroidia, Bacilli), which positively correlated with yield.
• Susceptible cultivars showed lower, more dispersed KBS abundance, negatively correlating with yield, indicating a genotype-dependent effect.

Conclusions:

• Sorghum genotype significantly shapes the phyllosphere microbiome, influencing the abundance of keystone beneficial specialists (KBS) and ultimately impacting crop yield.
• Keystone beneficial specialists (KBS) represent a host-driven microbial mechanism linking phyllosphere composition to sorghum yield.
• These findings suggest KBS as potential targets for microbiome-informed breeding strategies or foliar microbial applications to enhance crop productivity.