Extracellular invertase is involved in the regulation of clubroot disease in Arabidopsis thaliana

Abstract

Clubroot disease of Brassicaceae is caused by an obligate biotrophic protist, Plasmodiophora brassicae. During root gall development, a strong sink for assimilates is developed. Among other genes involved in sucrose and starch synthesis and degradation, the increased expression of invertases has been observed in a microarray experiment, and invertase and invertase inhibitor expression was confirmed using promoter::GUS lines of Arabidopsis thaliana. A functional approach demonstrates that invertases are important for gall development. Different transgenic lines expressing an invertase inhibitor under the control of two root-specific promoters, Pyk10 and CrypticT80, which results in the reduction of invertase activity, showed clearly reduced clubroot symptoms in root tissue with highest promoter expression, whereas hypocotyl galls developed normally. These results present the first evidence that invertases are important factors during gall development, most probably in supplying sugars to the pathogen. In addition, root-specific repression of invertase activity could be used as a tool to reduce clubroot symptoms.

Infection byRhodococcus fasciansmaintains cotyledons as a sink tissue for the pathogen

“…To assess the impact of R. fascians on the source-sink dynamics of the germinating pea, expression of sucrose and amino acid transporter gene family members (SUT and AAP), cell wall invertase (CWINV) and SWEET were monitored. Enhanced expression of CWINV has been reported in several plant-pathogen interactions (Berger et al, 2007;Depuydt et al, 2009;Chandran et al, 2010;Siemens et al, 2011). Interaction between cytokinins and CWINV is well documented, in relation to both cell division (Roitsch and Gonz alez, 2004;Jameson and Song, 2016) and source-sink dynamics (Ehneß and Roitsch, 1997;Albacete et al, 2015).…”

Temporal Changes in Allocation and Partitioning of New Carbon as 11C Elicited by Simulated Herbivory Suggest that Roots Shape Aboveground Responses in Arabidopsis

“…In Arabidopsis, invertases are not only the main route of Suc metabolism but are essential for normal plant growth and development (Barratt et al, 2009). Invertases also play a crucial role in regulating the supply of photosynthate to naturally occurring sink tissues (Tang et al, 1999;Weschke et al, 2003;Heyer et al, 2004;Roitsch and González, 2004) and are known to be up-regulated during gall formation (Rehill and Schultz, 2003;Siemens et al, 2011) and after wounding and insect attack (Zhang et al, 1996;Ohyama et al, 1998;Rosenkranz et al, 2001;Arnold and Schultz, 2002).…”

Understanding the Role of Defective Invertases in Plants: Tobacco Nin88 Fails to Degrade Sucrose

“…Their function is most prominent in sinks with no plasmodesmatal connections between cells, such as developing seeds and pollen (Proels et al, 2006;Hirsche et al, 2009;Kang et al, 2009). The expression and activity of cwINVs are regulated by a number of stimuli that are known to affect carbohydrate requirements, such as phytohormones (Balibrea-Lara et al, 2004;Hayes et al, 2010) and pathogen infection (Benhamou et al, 1991;Siemens et al, 2011). The activity of cwINVs is not only tightly regulated at both transcriptional and posttranscription levels; at the posttranslational level as well, cwINVs can be targeted by endogenous compartment-specific inhibitor proteins (Rausch and Greiner, 2003;Ruan et al, 2009).…”