Pectin modifications promote haustoria development in the parasitic plantPhtheirospermum japonicum

Abstract

Parasitic plants are globally prevalent pathogens with important ecological functions but also potentially devastating agricultural consequences. Common to all parasites is the formation of the haustorium which requires parasite organ development and tissue invasion into the host. Both processes involve cell wall modifications. Here, we investigated a role for pectins during haustorium development in the facultative parasitic plant Phtheirospermum japonicum. Using transcriptomics data from infected Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa), we identified genes for multiple P. japonicum pectin methylesterases (PMEs) and their inhibitors (PMEIs) whose expression was upregulated by haustoria formation. Changes in PME and PMEI expression were associated with tissue-specific modifications in pectin methylesterification. While de-methylesterified pectins were present in outer haustorial cells, highly methylated pectins were present in inner vascular tissues, including the xylem bridge that connects parasite to host. Specifically blocking xylem bridge formation in the haustoria inhibited several PME and PMEI genes from activating. Similarly, inhibiting PME activity using chemicals or by overexpressing PMEI genes delayed haustoria development. Our results suggest a dynamic and tissue-specific regulation of pectin contributes to haustoria initiation and to the establishment of xylem connections between parasite and host.

Melting the wall: plant parasitism entails pectin modification

“…External application of epiBL not only decreased haustoria formation, but also reduced the expression of above selected PjPMEs and PjPMEIs . 1 Additionally, LM19 and LM20 antibodies-based immunohistochemical staining of haustoria showed reduced accumulation of both unmethylesterified and highly methylesterified pectins after epiBL treatment. Interestingly, P. japonicum could efficiently infect BRl1-EMS-SUPPRESSOR 1 mutants (bes1–2 and bes1-D) having modified brassinosteroid signaling.…”

“…The size of the scale bar is 100 µM in each microscopic figure. The figure is adapted and modified from an open-access article by Leso et al, (2023) 1 that permits unrestricted use.…”

“… 2 , 3 In a recent study, Leso et al revealed the mechanism of haustoria development and parasitism by P. japonicum . 1 The authors identified a total of 60 PjPMEs and 62 PjPMEIs using available proteome data 8 and revealed their homology with the AtPME and AtPMEI sequences of the host plant Arabidopsis thaliana . The expression profiling using the transcriptome data of time-course infection at the haustorium development site of A. thaliana , and intrusive cells and non-intrusive cells of rice revealed increased expression of several PjPMEs and PjPMEIs in both plants.…”

Exploring Information Exchange between Thesium chinense and Its Host Prunella vulgaris through Joint Transcriptomic and Metabolomic Analysis

“…The haustorium plays a crucial role in the interaction between parasitic plants and their hosts. Early in the commensal process, it facilitates the parasite’s attachment and invasion of the host, and subsequently, it enables the uptake of nutrients, hormones and signaling molecules [ 4 ]. The symplastic continuity allows for the transfer of macromolecules and genetic materials between the hosts and the parasites [ 5 ].…”

Exploring information exchange betweenThesium chinenseand its hostPrunella vulgaristhrough joint transcriptomic and metabolomic analysis

“…During the interaction with their hosts, the haustorium exhibits dynamic changes in its functions. Early in the commensal process, the haustorium aids parasite in host attachment and invasion, and subsequently, it facilitates the uptake of nutrients, hormones and signaling molecules [5] . The resulting symplastic continuity enables macromolecules or genetic materials such as RNA to be transferred between the hosts and the parasites [6] .…”