Fungal Histidine Phosphotransferase Plays a Crucial Role in Photomorphogenesis and Pathogenesis in Magnaporthe oryzae

Abstract

Two-component signal transduction (TCST) pathways play crucial roles in many cellular functions such as stress responses, biofilm formation, and sporulation. The histidine phosphotransferase (HPt), which is an intermediate phosphotransfer protein in a two-component system, transfers a phosphate group to a phosphorylatable aspartate residue in the target protein(s), and up-regulates stress-activated MAP kinase cascades. Most fungal genomes carry a single copy of the gene coding for HPt, which are potential antifungal targets. However, unlike the histidine kinases (HK) or the downstream response regulators (RR) in two-component system, the HPts have not been well-studied in phytopathogenic fungi. In this study, we investigated the role of HPt in the model rice-blast fungal pathogen Magnaporthe oryzae. We found that in M. oryzae an additional isoform of the HPT gene YPD1 was expressed specifically in response to light. Further, the expression of light-regulated genes such as those encoding envoy and blue-light-harvesting protein, and PAS domain containing HKs was significantly reduced upon down-regulation of YPD1 in M. oryzae. Importantly, down-regulation of YPD1 led to a significant decrease in the ability to penetrate the host cuticle and in light-dependent conidiation in M. oryzae. Thus, our results indicate that Ypd1 plays an important role in asexual development and host invasion, and suggest that YPD1 isoforms likely have distinct roles to play in the rice-blast pathogen M. oryzae.

Alternative splicing diversifies the transcriptome and proteome of the rice blast fungus during host infection

“…We also found AS events derived from MoPTEN , a gene that was shown to produce two transcripts, in our RNA-seq data. One isoform ( MoPTEN-1 ) is involved in conidiation and appressorial formation while the second ( MoPTEN-2 ) is needed for invasive hyphal growth [ 39 ], suggesting that motif changes caused by AS made them perform different functions.…”

“…Two M. oryzae genes subjected to AS, including MoYPD and MoSOM1 , contribute to virulence [ 37 , 38 ]. Two AS isoforms derived from MoPTEN , a gene important for growth and pathogenesis, seem to perform distinct functions [ 39 ]. A previous study investigated AS profiles in an M. oryzae (previously called M. grisea ) strain by sequencing expressed sequence tags (ESTs) [ 40 ].…”

PlMAPK10, a Mitogen-Activated Protein Kinase (MAPK) in Peronophythora litchii, Is Required for Mycelial Growth, Sporulation, Laccase Activity, and Plant Infection

“…In addition, a specialized type of MAPKs in fungi and mammalian was termed as stress-activated protein kinases (SAPKs), as it is responsible for stress response, including heat shock, hyperosmolarity, ultraviolet (UV) light irradiation, and oxidative stress ( Brown et al, 2014 ). Examples of SAPKs from fungi include Magnaporthe oryzae YPD1 regulating penetration and conidiation ( Mohanan et al, 2017 ), Mycosphaerella graminicola Hog1 involved in osmosensitivity and dimorphic transition in fungal pathogenicity ( Mehrabi et al, 2006 ), and Bipolaris oryzae SRM1 for tolerance to hyperosmolarity, hydrogen peroxide (H 2 O 2 ), and UV exposure ( Moriwaki et al, 2006 ). On the other hand, mammalian p38s and JNKs are involved in the inflammatory and stress responses ( Kyriakis et al, 2004 ; Chadee and Kyriakis, 2010 ).…”

Glycerol-3-Phosphate Shuttle Is Involved in Development and Virulence in the Rice Blast Fungus Pyricularia oryzae

“…Aerial hyphal differentiation and conidial development were controlled by a light–dark cycle in P. oryzae . Of seven genes encoding light-sensitive proteins ( PoWC-1 , TWL , TIG1 , GCN5 , YPD1 , PoSIR2 , and TRX2 ) ( Lee et al, 2006 ; Ding et al, 2010 ; Fernandez et al, 2014a ; Deng et al, 2015 ; Zhang et al, 2016 , 2017 ; Mohanan et al, 2017 ), two genes ( PoSIR2 and TRX2 ) were found to be significantly up-regulated in Δ Pogpd2 under a light–dark cycle (increased to 1.5- and 1.6-fold), but not in a continuous dark condition ( Figure 6C ).…”