Increased callose deposition in plants lacking DYNAMIN-RELATED PROTEIN 2B is dependent upon POWDERY MILDEW RESISTANT 4

Abstract

Callose deposition within the cell wall is a well-documented plant immune response to pathogenic organisms as well as to pathogen-/microbe-associated molecular patterns (P/MAMPs). However, the molecular mechanisms that modulate pathogen-induced callose deposition are less understood. We reported previously that Arabidopsis plants lacking the vesicle trafficking component DYNAMIN-RELATED PROTEIN 2B (DRP2B) display increased callose deposition in response to the PAMP flg22. Here, we show that increased number of flg22-induced callose deposits in drp2b leaves is fully dependent on the callose synthase POWDERY MILDEW RESISTANT 4 (PMR4). We propose that in addition to functioning in flg22-induced endocytosis of the plant receptor, FLAGELLIN SENSING 2, DRP2B may regulate the trafficking of proteins involved in callose synthesis, such as PMR4, and/or callose degradation.

Exocyst components promote an incompatible interaction between Glycine max (soybean) and Heterodera glycines (the soybean cyst nematode)

“…The results presented here reveal that the expression of certain exocyst genes (EXOC7-H4-1) occurs outside of the boundary of the parasitized root cells. In A. thaliana, the vesicle transport machinery involving the exocyst acts at some level to facilitate callose deposition 18,19,52,85,[95][96][97][98][99][100][101][102] . Systemic processes outside of the vicinity of infection as well as structural modifications of G. max roots, including callose deposition and cell wall modification, have been observed 33,34,51,103 .…”

An expanded role of the SNARE-containing regulon as it relates to the defense process that Glycine max has to Heterodera glycines

“…The work presented here experimentally tests components that would be expected to function within the regulon, but lie outside of the genetically defined apparatus (Humphry et al 2010). The selected genes encoding myosin XI and callose synthase (CS) relate to their previously reported defense roles and how the roles relate to vesicle trafficking (Ellinger et al 2013;Ellinger, Glöckner, et al 2014;Ellinger, Sode, et al 2014;Yang et al 2014;Peremyslov et al 2015;Leslie et al 2016;De Benedictis et al 2018;Sassmann et al 2018;Wang et al 2018). Furthermore, an examination of CS has been performed due to our previous observations that have shown an apparent increase in callose labeling at sites of engineered resistance in transgenic lines overexpressing GmSYP121-1 (GmSYP121-1-OE), leading to a successful defense response while in contrast GmSYP121-1-RNAi transgenic lines exhibit an impaired defense response and an apparent decrease in callose at sites of successful parasitism (Sharma et al 2016).…”

The Ralstonia solanacearum effector RipN suppresses plant PAMP‐triggered immunity, localizes to the endoplasmic reticulum and nucleus, and alters the NADH/NAD+ ratio in Arabidopsis

“…Five‐week‐old Arabidopsis leaves were infiltrated with 1 μ m flg22, collected 10 h later, stained with aniline blue and visualized with a fluorescence microscope, as described previously (Leslie et al. , ). Callose deposits were calculated using ImageJ software.…”