Expression Analysis of Rice Defense-Related Genes in Turfgrass in Response to Magnaporthe grisea

Abstract

Magnaporthe grisea (anamorph = Pyricularia grisea) causes blast on rice (Oryza sativa) and gray leaf spot on turfgrass. Gray leaf spot is a serious disease on St. Augustinegrass (Stenotaphrum secundatum), perennial ryegrass (Lolium perenne), and tall fescue (Festuca arundinacea). Virulence assays performed in this study revealed that M. grisea collected from rice could also cause disease on St. Augustinegrass and tall fescue. One rice isolate, Che86061, caused similar disease reactions on susceptible cultivars of rice and St. Augustinegrass and an incompatible interaction on resistant cultivars of both species. To explore whether similar defense-related genes are expressed in rice and St. Augustinegrass, a rice cDNA library was screened using pooled cDNAs derived from M. grisea-infected St. Augustinegrass. Thirty rice EST (expressed sequence tag) clones showing differential expression in St. Augustinegrass following M. grisea inoculation were identified and classified into six putative functional groups. Northern blot analyses of seven EST clones that collectively represented each putative functional group confirmed that the expression of five out of seven EST clones was similar in both rice and St. Augustinegrass. This study represents one of the first attempts to use a broad-scale genomic approach and resources of a model monocot system to study defense gene expression in St. Augustinegrass following M. grisea infection.

Registration of ‘DALSA 0605’ St. Augustinegrass

“…Palmetto (diploid pollen parent) was classified as susceptible. This finding concurs with other researchers who have attributed resistance to biotic stress in St. Augustinegrass to ploidy level (Reinert et al, 1986; Busey, 2003) and is consistent with previously reported observations (Busey, 2003; Harmon et al, 2005; Jo et al, 2007), which indicated that the introduced African polyploid FX‐10 exhibits resistance to M. grisea . Figure 3 shows DALSA 0605 expressing high levels of tolerance to the gray leaf spot disease relative to ‘Mercedes’ and Raleigh in a study conducted in 2009 in Dallas under field conditions (Metz et al, 2012).…”

Comparison of screening methods to evaluate the response of St. Augustine grass to Magnaporthe oryzae

“…, 1986; Busey, 2003), and is consistent with previously reported observations (Busey, 2003; Harmon et al. , 2005; Jo et al. , 2007), which indicated that the introduced African polyploid, FX‐10, exhibits resistance to M. oryzae.…”

“…LS was determined by measuring lesion length using a handheld digital caliper (Control Company). Ten leaves were sampled from each replicate genotype and LS was rated on a scale of 0–5, where 0 = no symptoms, 1 = pinhead size lesions, 2 = lesions 1·5 mm in size, 3 = lesions 2·0–3·0 mm in size, 4 = lesions 3·0–5·0 mm in size with clear margins, and 5 = over 50% of leaf diseased with coalesced lesions (Jo et al. , 2007).…”

Requirement of a Mitogen-Activated Protein Kinase for Appressorium Formation and Penetration of Insect Cuticle by the Entomopathogenic Fungus Beauveria bassiana

“…Transcript levels of six genes (A30, A131, A668, A1023, A886 and A781), which had similarity to histone H3, rRNA intron-encoded homing endonuclease, CHK1 checkpoint-like protein, ATP-dependent RNA helicase, translation elongation factor 1 alpha and a putative aldehyde dehydrogenase, respectively, were also markedly reduced in ⌬Bbmpk1 mutants during appressorium formation. These results suggest that BbMPK1 probably influences DNA repair (11,18), transcription (11,17), chromatin remodeling (11,25), rRNA processing, small nucleolar RNA accumulation (11), translation and posttranslational modification (34,55), oxidation of aldehydes (24,45), and likely other cellular processes. In addition, a virus hemagglutinin esterase homolog (A140) was found to be exclusively expressed in WT, but its origin and role in eukaryotic cells remains unknown.…”