SreC-dependent adaption to host iron environments regulates the transition of trophic stages and developmental processes of Curvularia lunata.

Plant pathogens are challenged by host-derived iron starvation or excess during infection, but the mechanism of plant pathogens rapidly adapting to the dynamic host iron environments to assimilate iron for invasion and colonization remains largely unexplored. Here, we found that the GATA transcription factor SreC in Curvularia lunata is required for virulence and adaption to the host iron excess environment. SreC directly binds to the ATGWGATAW element in an iron-dependent manner to regulate the switch between different iron assimilation pathways, conferring adaption to host iron environments in different trophic stages of C.

An efficient targeted gene deletion approach for Cochliobolus heterostrophus using Agrobacterium tumefaciens-mediated transformation.

Cochliobolus heterostrophus is a plant pathogenic fungus of southern corn leaf blight, which has been regarded as a model necrotrophic plant pathogen. Many methods have been developed to knock out targeted genes in C. heterostrophus, of which the most widely-used one is protoplast-mediated transformation.

Highly efficient gene knockout system in the maize pathogen Colletotrichum graminicola using Agrobacterium tumefaciens-mediated transformation (ATMT).

Colletotrichum graminicola, a hemibiotrophic pathogenic fungus, is the causal agent of anthracnose of maize, which causes significant yield losses worldwide, especially in warm and humid maize production regions. An efficient targeted genes knockout protocol is crucial to explore molecular mechanisms of fungal virulence to the host. In this study, we established a gene knockout transformation system by employing Agrobacterium tumefaciens-mediated transformation to knockout genes in M 1.

Iron redistribution induces oxidative burst and resistance in maize against Curvularia lunata.

ΔClnps6 induced iron redistribution in maize B73 leaf cells and resulted in reactive oxygen species (ROS) burst to enhance plant resistance against Curvularia lunata. Iron is an indispensable co-factor of various crucial enzymes that are involved in cellular metabolic processes and energy metabolism in eukaryotes. For this reason, plants and pathogens compete for iron to maintain their iron homeostasis, respectively.

ClNOX1/ClNOXR-mediated MAPK and cAMP-PKA signalling pathways and ROS metabolism are involved in Curvularia lunata sexual reproduction and host infection.

NADPH oxidases (NOXs) and hydrogen peroxide (H O ) are involved in physiological and pathological processes, and cell fate decisions in organisms. However, regulatory mechanism of NOXs and the role of H O on fungal sexual reproduction and host infection remain largely unexplored. Here, we identified ROS metabolic genes and key signalling genes of MAPK and cAMP-PKA pathways in Curvularia lunata, which were NOX ClNOX1 and ClNOXR, superoxide dismutase ClSOD1 and catalase ClCAT4, redox-regulated transcription factor ClAP1, Ras small GTPases Clg2P, pheromone-response MAPK ClK1 and cAMP-PKA ClSCHA, and characterized the functions of these genes.

Virulence and Molecular Diversity in the Population Causing Maize Eyespot in China.

Maize eyespot, caused by , has become a major yield-limiting factor in maize planting areas in northeast China. Limited information is available on pathotypes, virulence, and the genetic diversity of the population. We analyzed virulence and genetic diversity of 103 isolates collected from six provinces in China with differential hosts and the amplified fragment length polymorphism (AFLP) technique, respectively.

NADPH Oxidase ClNOX2 Regulates Melanin-Mediated Development and Virulence in .

The role of NADPH oxidases (NOXs) in pathogenesis and development in the Curvularia leaf spot agent remains poorly understood. In this study, we identified . ClNOX2, which localized to the plasma membrane and was responsible for reactive oxygen species (ROS) generation.

The key iron assimilation genes ClFTR1, ClNPS6 were crucial for virulence of Curvularia lunata via initiating its appressorium formation and virulence factors.

Iron is virtually an essential nutrient for all organisms, to understand how iron contributes to virulence of plant pathogenic fungi, we identified ClFTR1 and ClNPS6 in maize pathogen Curvularia lunata (Cochliobolus lunatus) in this study. Disruption of ClNPS6 significantly impaired siderophore biosynthesis. ClFTR1 and ClNPS6 did mediate oxidative stress but had no significant impact on vegetative growth, conidiation, cell wall integrity and sexual reproduction.

Virulence, Molecular Diversity, and Mating Type of in China.

Curvularia leaf spot (CuLS), caused by , is a devasting foliar disease in the maize-growing regions of China. Resistant varieties were widely planted in these regions in response to CuLS. However, over time, has gradually adapted to the selective pressure and, in recent years, the incidence of CuLS has increased.

Agrobacterium tumefaciens-mediated transformation as an efficient tool for insertional mutagenesis of Kabatiella zeae.

Agrobacterium tumefaciens-mediated transformation (ATMT) has been widely used in filamentous fungi. In this study, an efficient Agrobacterium tumefaciens-mediated transformation approach was developed for the plant pathogenic fungus, Kabatiella zeae, the causative pathogen of eyespot in maize. Five parameters were selected to optimize efficiencies of transformation.

Using overlap-extension PCR technique to fusing genes for constructing recombinant plasmids.

Overlap-extension PCR is a method for splice of gene segments to produce focused fragments for constructing recombinant plasmid, but its complexity limits its application. To simplify the protocol and to improve the effectiveness, we employed gradient temperatures to replace the single annealing temperature in the thermo-cycling program, and optimize the templates ratio. The concentration of each fragment was adjusted to 10 ng µl .

Agrobacterium tumefaciens-mediated transformation as an efficient tool for insertional mutagenesis of Cercospora zeae-maydis.

An efficient Agrobacterium tumefaciens-mediated transformation (ATMT) approach was developed for the plant pathogenic fungus, Cercospora zeae-maydis, which is the causative agent of gray leaf spot in maize. The transformation was evaluated with five parameters to test the efficiencies of transformation. Results showed that spore germination time, co-cultivation temperature and time were the significant influencing factors in all parameters.

Efficient gene knockout in the maize pathogen Setosphaeria turcica using Agrobacterium tumefaciens-mediated transformation.

Setosphaeria turcica, a hemibiotrophic pathogenic dothideomycete, is the causal agent of Northern Leaf Blight of maize, which periodically causes significant yield losses worldwide. To explore molecular mechanisms of fungal pathogenicity and virulence to the host, an efficient targeted gene knockout transformation system using Agrobacterium tumefaciens was established with field collected strains. The starting materials, incubation time, induction medium type, Agrobacterium cell density, and method of co-incubation were optimized for deletion of 1,3,8-trihydroxynaphthalene reductase, a gene in the melanin biosynthesis pathway, as a test case.

Comparative genome structure, secondary metabolite, and effector coding capacity across Cochliobolus pathogens.

The genomes of five Cochliobolus heterostrophus strains, two Cochliobolus sativus strains, three additional Cochliobolus species (Cochliobolus victoriae, Cochliobolus carbonum, Cochliobolus miyabeanus), and closely related Setosphaeria turcica were sequenced at the Joint Genome Institute (JGI). The datasets were used to identify SNPs between strains and species, unique genomic regions, core secondary metabolism genes, and small secreted protein (SSP) candidate effector encoding genes with a view towards pinpointing structural elements and gene content associated with specificity of these closely related fungi to different cereal hosts. Whole-genome alignment shows that three to five percent of each genome differs between strains of the same species, while a quarter of each genome differs between species.