Homologs of CsLOB1 in citrus function as disease susceptibility genes in citrus canker

The lateral organ boundary domain (LBD) genes encode a group of plant-specific proteins that function as transcription factors in regulating plant growth and development. Citrus sinensis lateral organ boundary 1 (CsLOB1) is a member of the LBD family and functions as a disease susceptibility (S) gene in citrus bacterial canker (CBC). Thirty-four LBD members have been identified from Citrus sinensis genome. We assessed the potential for additional members of the LBD genes in citrus to function as surrogates for CsLOB1 in CBC and compared host gene expression upon induction of different LBD genes. Using custom designed TAL effector (dTALe), two members of the same clade as CsLOB1, named CsLOB2 and CsLOB3, were found to be capable of functioning similarly to CsLOB1 in CBC. RNA sequencing and quantitative RT-PCR analyses revealed a set of cell wall metabolic genes that are associated with CsLOB1, CsLOB2 and CsLOB3 expression and may represent downstream genes involved in CBC. This article is protected by copyright. All rights reserved.