The Peroxisomal-CoA Synthetase MoPcs60 Is Important for Fatty Acid Metabolism and Infectious Growth of the Rice Blast Fungus

Abstract

Fatty acid metabolism is important for the maintenance of fatty acid homeostasis. Free fatty acids, which are toxic in excess, are activated by esterification with coenzyme A (CoA) and then subjected to β-oxidization. Fatty acid β-oxidation-related genes play critical roles in the development and virulence of several phytopathogens. In this study, we identified and characterized a peroxisomal-CoA synthetase in the rice blast fungus Magnaporthe oryzae, MoPCS60, which is a homolog of PCS60 in budding yeast. MoPCS60 was highly expressed during the conidial and early infectious stages and was induced under oleate treatment. Targeted deletion of MoPCS60 resulted in a significant reduction in growth rate when oleate and olive oil were used as the sole carbon sources. Compared with the wild-type strain Guy11, the ΔMopcs60 mutant exhibited fewer peroxisomes, more lipid droplets, and decreased pathogenicity. The distribution of MoPcs60 varied among developmental stages and was mainly localized to peroxisomes in the hyphae, conidia, and appressoria when treated with oleate. Our results suggest that MoPcs60 is a key peroxisomal-CoA synthetase involved in fatty acid β-oxidation and pathogenicity in rice blast fungi.

The acyl-CoA synthetase Tg ACS1 allows neutral lipid metabolism and extracellular motility in Toxoplasma gondii through relocation via its peroxisomal targeting sequence (PTS) under low nutrient conditions

“…1b ), belonging to bubble gum subfamily ACSBG, and furthermore allowing β-oxidation in yeast peroxisome ( 26 , 52 ). To test whether Tg ACS1 is an ACS that can rescue the activity of a yeast mutant deficient of peroxisomal acyl-CoA activity, we used the Saccharomyces PCS60 deficient strain in the presence of doxorubicin (12 µg/mL), a cancer drug inducing lipid peroxidation that is lethal in the absence of PCS60 ( 32 , 53 ). To determine the concentration of doxorubicin to be used for our experiments, we grew ∆Pcs60 in the presence of different concentrations (6, 12, and 24 µg/mL).…”

“…S6e). We then transformed Tg ACS1 expressing vector (pRS426-MET25- Tg ACS1) into the ∆ PCS60 yeast strain similarly to what has been done for the Magnaporthe oryzae PCS60 homolog involved in LD mobilization and fatty acid activation for β-oxidation ( 32 ). We first confirmed that ∆PCS60 yeast strain was able to grow normally without doxorubicin (in red, Fig.…”

“…More importantly, bubble gum ACSs, ACSBG, are specific to a single target organelle, peroxisome, where β-oxidation takes place in certain organisms. Peroxisomal ACSBG cannot complement the mitochondrial ACSs and vice versa ( 31 , 32 ).…”

The Devastating Rice Blast Airborne Pathogen Magnaporthe oryzae—A Review on Genes Studied with Mutant Analysis

“…The pth2 mutants lost the CAT activities and showed a compromised lipid metabolism in appressoria and attenuated fungal virulence, indicating the importance of acetyl-CoA in appressoria function and fungal pathogenicity [ 220 ]. Meanwhile, the peroxisomal-CoA synthetase PCS60 is also involved in fatty acid metabolism and contributes to the growth of infection hyphae and fungal pathogenicity [ 221 ]. The β-oxidation of fatty acids also results in the reoxidation of NADH to NAD+ in peroxisomes.…”

The MoLfa1 Protein Regulates Fungal Development and Septin Ring Formation in Magnaporthe oryzae

“…LCFAs are fatty acids with more than 12 carbon atoms and are an important component of PIPs. LCFAs have essential biological roles as nutrients and substrates for signaling molecules [ 22 ]. LCFAs also play crucial roles in physiological and pathological processes.…”