A nuclear contortionist: the mitotic migration ofMagnaporthe oryzaenuclei during plant infection

Abstract

Magnaporthe oryzae is a filamentous fungus, which causes significant destruction to cereal crops worldwide. To infect plant cells, the fungus develops specialised constricted structures such as the penetration peg and the invasive hyphal peg. Live-cell imaging of M. oryzae during plant infection reveals that nuclear migration occurs during intermediate mitosis, in which the nuclear envelope neither completely disassembles nor remains entirely intact. Remarkably, in M. oryzae, mitotic nuclei show incredible malleability while undergoing confined migration through the constricted penetration and invasive hyphal pegs. Here, we review early events in plant infection, discuss intermediate mitosis, and summarise current knowledge of intermediate mitotic nuclear migration in M. oryzae.

Focal Accumulation of ROS Can Block Pyricularia oryzae Effector BAS4-Expression and Prevent Infection in Rice

“…Penetration of virulent P. oryzae hyphae into rice tissue invaginates the plasma membrane, and the invading hyphae expand within the first occupied epidermal rice cell, thereby perturbing plant hormone signaling before invading surrounding cells [ 36 , 37 ]. To analyze ROS accumulation, ROS quantity and distribution were detected in rice cells during compatible and incompatible interactions with P. oryzae .…”

From appressorium to transpressorium—Defining the morphogenetic basis of host cell invasion by the rice blast fungus

“…Is there a cell cycle dependency for transpressorium development, as there is for appressorium formation? Mitosis occurs at cell junctions [39], but is this a prerequisite for transpressorium formation, and, if so, does a similar S phase checkpoint mechanism act at this time [21]? Is there a quorum sensing or nutritional dependency for transpressorium development?…”

Tandem DNA repeats contain cis‐regulatory sequences that activate biotrophy‐specific expression of Magnaporthe effector gene PWL2

“…M. oryzae causes devastating blast disease in rice and other economically important crops. Recent live‐cell imaging studies, making use of a rice sheath infection assay and various fluorescent reporters, revealed the cellular dynamics associated with the early biotrophic stage of rice infection (Giraldo & Valent, 2013; Jones et al, 2017; Kankanala et al., 2007; Khang et al., 2010; Pfeifer & Khang, 2018; Sakulkoo et al., 2018; Shipman et al., 2017) (Figure 1a). M. oryzae biotrophic invasion begins when a single‐celled appressorium produces a penetration peg that breaches the rice cell wall, allowing the fungus to enter a living rice cell.…”