Suppresses Tomato Root Growth by Downregulation of a Wall-Associated Receptor Kinase.

The root architecture of a range of host plants is altered in response to infection. This work aimed to identify host genes involved in root development during infection. A deficient mutant of the type III secretion system regulator was created in GMI1000. The mutant was impaired in virulence but showed a similar suppressive effect as wild-type GMI1000 on tomato root development. Based on comparative transcriptome analysis, 209 genes were found that showed the same changed expression pattern in GMI1000 and mutant infected roots relative to uninoculated roots. Among them, the wall-associated receptor kinase was substantially downregulated in GMI1000 and mutant infected roots. Knockdown of led to a shorter primary root length and fewer lateral roots in tomato as well as in . The is a pivotal target suppressed by to shape the altered root development during infection.