ERECTA, an LRR receptor‐like kinase protein controlling development pleiotropically affects resistance to bacterial wilt

Abstract

The last two authors contributed equally to this work. SummaryBacterial wilt, one of the most devastating bacterial diseases of plants worldwide, is caused by Ralstonia solanacearum and affects many important crop species. We show that several strains isolated from solanaceous crops in Europe are pathogenic in different accessions of Arabidopsis thaliana. One of these strains, 14.25, causes wilting symptoms in A. thaliana accession Landsberg erecta (Ler) and no apparent symptoms in accession Columbia (Col-0). Disease development and bacterial multiplication in the susceptible Ler accession depend on functional hypersensitive response and pathogenicity (hrp) genes, key elements for bacterial pathogenicity. Genetic analysis using Ler  Col-0 recombinant inbred lines showed that resistance is governed by at least three loci: QRS1 (Quantitative Resistance to R. solanacearum) and QRS2 on chromosome 2, and QRS3 on chromosome 5. These loci explain about 90% of the resistance carried by the Col-0 accession. The ERECTA gene, which encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) and affects development of aerial organs, is dimorphic in our population and lies close to QRS1. Susceptible Ler plants transformed with a wild-type ERECTA gene, and the LER line showed increased disease resistance to R. solanacearum as indicated by reduced wilt symptoms and impaired bacterial growth, suggesting unexpected cross-talk between resistance and developmental pathways.

Two New Alleles of the abscisic aldehyde oxidase 3 Gene Reveal Its Role in Abscisic Acid Biosynthesis in Seeds

“…Second, the aao3-1 mutation is present in a Ler background, whereas aao3-2 and aao3-3 mutations are in a Col background. The erecta mutant has a lesion in a Leu-rich repeat receptor-like kinase that affects development of aerial plant organs (Torii et al, 1996) and also leads to additional unexpected phenotypes (Godiard et al, 2003). Indeed, seeds of Ler ecotype are more sensitive to inhibition of germination by low exogenous concentrations of ABA than Col ecotype (data not shown).…”

Generation of Signaling Specificity in Arabidopsis by Spatially Restricted Buffering of Ligand–Receptor Interactions

“…The five uncharacterized EPFL family members could encode stomatal regulators, growth regulators, or ligands active in some other ERf-dependent process, such as bacterial or fungal pathogen resistance (Godiard et al, 2003;Llorente et al, 2005). In neither growth nor stomatal development does loss of the currently characterized EPFLs fully recapitulate the suite of defects generated by loss of the ERf.…”

“…This hypothesis might also account for the basal phenotypic variability observed in tmm single mutants. Alternatively, this variability might reflect the capacity of ERf receptors and/or their downstream mitogenactivated protein kinase cascade to transduce environmental cues and stresses (Godiard et al, 2003;Llorente et al, 2005;Nakagami et al, 2005), perhaps coupled with enhanced sensitivity to such cues and stresses in the absence of TMM. Independent of its cause, this variability must be considered when (A) Model for CHALf and EPF1/2 interactions with TMM and ERf receptors in different regions of wild-type and tmm seedlings.…”

“…Demonstration of ER functions in development (cell proliferation, cell fate specification, and tissue patterning in most aerial organs), in homeostasis, and in immunity indicate that ER is a central player in multiple signaling contexts (Godiard et al, 2003;Xu et al, 2003;Shpak et al, 2004Shpak et al, , 2005Masle et al, 2005;Pillitteri et al, 2007). ER is partially redundant with two close paralogs, ERECTA-LIKE1 (ERL1) and ERL2, and these three genes are known as the ER family (ERf).…”

Phylogenomic Analysis of the Receptor-Like Proteins of Rice and Arabidopsis

“…Arabidopsis CLAVATA1 (Clark et al, 1997) and RLK5/ HAESA (Walker, 1993) are involved in development. Interestingly, Arabidopsis ERECTA has been reported to play a role in both development and defense (Torii et al, 1996;Godiard et al, 2003).…”