A complex receptor locus confers responsiveness to necrosis and ethylene-inducing like peptides in Brassica napus.

Brassica crops are susceptible to diseases which can be mitigated by breeding for resistance. MAMPs (microbe-associated molecular patterns) are conserved molecules of pathogens that elicit host defences known as pattern-triggered immunity (PTI). Necrosis and Ethylene-inducing peptide 1-like proteins (NLPs) are MAMPs found in a wide range of phytopathogens. We studied the response to BcNEP2, a representative NLP from Botrytis cinerea, and showed that it contributes to disease resistance in Brassica napus. To map regions conferring NLP response, we used the production of reactive oxygen species (ROS) induced during PTI across a population of diverse B. napus accessions for associative transcriptomics (AT), and bulk segregant analysis (BSA) on DNA pools created from a cross of NLP-responsive and non-responsive lines. In silico mapping with AT identified two peaks for NLP responsiveness on chromosomes A04 and C05 whereas the BSA identified one peak on A04. BSA delimited the region for NLP-responsiveness to 3 Mbp, containing ~245 genes on the Darmor-bzh reference genome and four co-segregating KASP markers were identified. The same pipeline with the ZS11 genome confirmed the highest-associated region on chromosome A04. Comparative BLAST analysis revealed unannotated clusters of receptor-like protein (RLP) homologues on ZS11 chromosome A04. However, no specific RLP homologue conferring NLP response could be identified. Our results also suggest that BR-SIGNALLING KINASE1 may be involved with modulating the NLP response. Overall, we demonstrate that responsiveness to NLP contributes to disease resistance in B. napus and define the associated genomic location. These results can have practical application in crop improvement.

Necrosis and ethylene-inducing-like peptide patterns from crop pathogens induce differential responses within seven brassicaceous species.

Translational research is required to advance fundamental knowledge on plant immunity towards application in crop improvement. Recognition of microbe/pathogen-associated molecular patterns (MAMPs/PAMPs) triggers a first layer of immunity in plants. The broadly occurring family of necrosis- and ethylene-inducing peptide 1 (NEP1)-like proteins (NLPs) contains immunogenic peptide patterns that are recognized by a number of plant species. Arabidopsis can recognize NLPs by the pattern recognition receptor AtRLP23 and its co-receptors SOBIR1, BAK1, and BKK1, leading to induction of defence responses including the production of reactive oxygen species (ROS) and elevation of intracellular [Ca2+]. However, little is known about NLP perception in Brassica crop species. Within 12 diverse accessions for each of six Brassica crop species, we demonstrate variation in response to Botrytis cinerea NLP BcNEP2, with Brassica oleracea (CC genome) being nonresponsive and only two Brassica napus cultivars responding to BcNEP2. Peptides derived from four fungal pathogens of these crop species elicited responses similar to BcNEP2 in B. napus and Arabidopsis. Induction of ROS by NLP peptides was strongly reduced in Atrlp23, Atsobir1 and Atbak1-5 Atbkk1-1 mutants, confirming that recognition of Brassica pathogen NLPs occurs in a similar manner to that of HaNLP3 from Hyaloperonospora arabidopsidis in Arabidopsis. In silico analysis of the genomes of two B. napus accessions showed similar presence of homologues for AtBAK1, AtBKK1 and AtSOBIR1 but variation in the organization of AtRLP23 homologues. We could not detect a strong correlation between the ability to respond to NLP peptides and resistance to B. cinerea.

Wild Edible Mushrooms from Turkey as Possible Anticancer Agents on HepG2 Cells Together with Their Antioxidant and Antimicrobial Properties.

This study was designed to reveal cell growth inhibitory potential of six different edible mushrooms: Ramaria flava, Agrocybe molesta, Volvopluteus gloiocephalus, Lactarius deliciosus, Bovista plumbea, and Tricholoma terreum on HepG2 cells together with their antioxidant and antibacterial power. Methanolic extracts of V gloiocephalus and aqueous extracts of R. flava had the most potential cytotoxic effects over HepG2 cells. The best results for 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities were obtained from both aqueous and methanolic extracts of R. flava. Methanolic extracts of T. terreum (IC50 = 1.62 mg/mL) and aqueous extracts of B. plumbea (IC50 = 0.49 mg/mL) showed maximum metal chelating activity. The highest reducing capacities were observed among the methanolic extracts of R. flava (EC50 = 1.65 mg/mL) and aqueous extracts of B. plumbea (EC50 = 1.71 mg/ mL). High-performance liquid chromatography analysis revealed the presence of many phenolic compounds in macrofungi; gallic acid and p-coumaric acid were the two main phenolics identified in all extracts. Antibacterial studies indicated that all six tested mushrooms showed antibacterial activity on at least three microorganisms. These results indicate that different extracts of the investigated mushrooms have considerable cytotoxic, antioxidant, and antibacterial properties and may be utilized as a promising source of therapeutics.