Exploring the Relationship Between Pattern-Triggered Immunity and Quantitative Resistance to pv. in Maize.

Bacterial leaf streak (BLS) of maize is an emerging foliar disease of maize in the Americas. It is caused by the gram-negative nonvascular bacterium pv. . There are no chemical controls available for BLS, and thus, host resistance is crucial for managing pv. . The objective of this study was to examine the genetic determinants of resistance to pv. in maize, as well as the relationship between other defense-related traits and BLS resistance. Specifically, we examined the correlations among BLS severity, severity for three fungal diseases, flg-22 response, hypersensitive response, and auricle color. We conducted quantitative trait locus (QTL) mapping for pv. resistance using the maize recombinant inbred line population Z003 (B73 × CML228). We detected three QTLs for BLS resistance. In addition to the disease resistance QTL, we detected a single QTL for auricle color. We observed significant, yet weak, correlations among BLS severity, levels of pattern-triggered immunity response and leaf flecking. These results will be useful for understanding resistance to pv. and mitigating the impact of BLS on maize yields.