The formation of nitrogen fixing root nodules by Medicago truncatula and Sinorhizobium meliloti requires communication between both organisms and coordinated differentiation of plant and bacterial cells. After an initial signal exchange, the bacteria invade the tissue of the growing nodule via plant-derived tubular structures, called infection threads. The bacteria are released from the infecti...

The location of lipopolysaccharides produced by Xanthomonas axonopodis pv. manihotis during pathogenesis on cassava (Manihot esculenta) was determined by fluorescence and electron microscopy immunolabeling with monoclonal antibodies. During the early stages of infection, pathogen lipopolysaccharides were detected on the outer surface of the bacterial envelope and in areas of the plant middle la...

The plant cell wall is one of the first physical interfaces encountered by plant pathogens and consists of polysaccharides, of which arabinan is an important constituent. During infection, the necrotrophic plant pathogen Botrytis cinerea secretes a cocktail of plant cell-wall-degrading enzymes, including endo-arabinanase activity, which carries out the breakdown of arabinan. The roles of arabin...

Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen ...

Ralstonia solanacearum is a soil and water-borne pathogen that can infect a wide range of plants and cause the devastating bacterial wilt disease. To successfully colonize a host, R. solanacearum requires the type III secretion system (T3SS), which delivers bacterial effector proteins inside the plant cells. HrpG is a central transcriptional regulator that drives the expression of the T3SS and ...

Plants contain numerous CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (ESR) (CLE) genes encoding small secreted peptide hormones that function in a variety of developmental and physiological processes. The first known Arabidopsis CLE gene was originally discovered through the analysis of clv3 mutants, which exhibit fasciated stems and an increased number of floral organs. In total, 32 CLE genes hav...

Degradation of pectin, a major component of plant cell wall, is important for fungal necrotrophs to achieve a successful infection. The activities of pectin methylesterases (PMEs) from both plants and pathogens and the degree and pattern of pectin methylesterification are critical for the outcome of plant-pathogen interaction. Partial degradation of pectin by pectin degrading enzymes releases o...

Polygalacturonase-inhibiting proteins are leucine-rich repeat proteins that inhibit fungal endopolygalacturonases. The interaction of polygalacturonase-inhibiting protein with endopolygalacturonases limits the destructive potential of endopolygalacturonases and may trigger plant defense responses induced by oligogalacturonides. We examined the expression of fungal pg and plant Pvpgip genes in b...

To allow rhizobial infection of legume roots, plant cell walls must be locally degraded for plant-made infection threads (ITs) to be formed. Here we identify a Lotus japonicus nodulation pectate lyase gene (LjNPL), which is induced in roots and root hairs by rhizobial nodulation (Nod) factors via activation of the nodulation signaling pathway and the NIN transcription factor. Two Ljnpl mutants ...