Search for: All records

The common rust disease of maize is caused by the obligate biotrophic fungusPuccinia sorghi. The maizeRp1-Dallele imparts resistance against theP.sorghiIN2 isolate by initiating a defense response that includes a rapid localized programmed cell death process, the hypersensitive response (HR). In this study, to identify AvrRp1-D fromP.sorghiIN2, we employed the isolation of haustoria, facilitated by a biotin-streptavidin interaction, as a powerful approach. This method proves particularly advantageous in cases where the genome information for the fungal pathogen is unavailable, enhancing our ability to explore and understand the molecular interactions between maize andP.sorghi. The haustorial transcriptome generated through this technique, in combination with bioinformatic analyses such as SignalP and TMHMM, enabled the identification of 251 candidate effectors. We ultimately identified two closely related genes,AvrRp1-D.1andAvrRp1-D.2, which triggered anRp1-D-dependent defense response inNicotiana benthamiana.AvrRp1-D-inducedRp1-D-dependent HR was further confirmed in maize protoplasts. We demonstrated that AvrRp1-D.1 interacts directly and specifically with the leucine-rich repeat (LRR) domain of Rp1-D through yeast two-hybrid assay. We also provide evidence that, in the absence of Rp1-D, AvrRp1-D.1 plays a role in suppressing the plant immune response. Our research provides valuable insights into the molecular interactions driving resistance against common rust in maize. 

Haplotype-level allelic characterization facilitates research on the functional, evolutionary and breeding-related features of extremely large and complex plant genomes. We report a 21.7-Gb chromosome-level haplotype-resolved assembly in Pinus densiflora. We found genome rearrangements involving translocations and inversions between chromosomes 1 and 3 of Pinus species and a proliferation of specific long terminal repeat (LTR) retrotransposons (LTR-RTs) in P. densiflora. Evolutionary analyses illustrated that tandem and LTR-RT-mediated duplications led to an increment of transcription factor (TF) genes in P. densiflora. The haplotype sequence comparison showed allelic imbalances, including presence–absence variations of genes (PAV genes) and their functional contributions to flowering and abiotic stress-related traits in P. densiflora. Allele-aware resequencing analysis revealed PAV gene diversity across P. densiflora accessions. Our study provides insights into key mechanisms underlying the evolution of genome structure, LTR-RTs and TFs within the Pinus lineage as well as allelic imbalances and diversity across P. densiflora. 

Abstract Autophagy in eukaryotes functions to maintain homeostasis by degradation and recycling of long-lived and unwanted cellular materials. Autophagy plays important roles in pathogenicity of various fungal pathogens, suggesting that autophagy is a novel target for development of antifungal compounds. Here, we describe bioluminescence resonance energy transfer (BRET)-based high-throughput screening (HTS) strategy to identify compounds that inhibit fungal ATG4 cysteine protease-mediated cleavage of ATG8 that is critical for autophagosome formation. We identified ebselen (EB) and its analogs ebselen oxide (EO) and 2-(4-methylphenyl)−1,2-benzisothiazol-3(2H)-one (PT) as inhibitors of fungal pathogensBotrytis cinereaandMagnaporthe oryzaeATG4-mediated ATG8 processing. The EB and its analogs inhibit spore germination, hyphal development, and appressorium formation inAscomycotapathogens,B. cinerea, M. oryzae,Sclerotinia sclerotiorumandMonilinia fructicola. Treatment with EB and its analogs significantly reduced fungal pathogenicity. Our findings provide molecular insights to develop the next generation of antifungal compounds by targeting autophagy in important fungal pathogens. 

This paper reports the first chip-based demonstration (at any frequency) of a CMOS front-end that generates and receives electromagnetic waves with rotating wave phase front (namely orbital angular momentum or OAM). The chip, based on a uniform circularly placed patch antenna array at 0.31THz, transmits reconfigurable OAM modes, which are digitally switched among the m=0 (plane wave), +1 (left-handed), −1 (right-handed) and superposition (+1)+(-1) states. The chip is also reconfigurable into a receiver mode that identifies different OAM modes with >10dB rejection of unintended modes. The array, driven by only one active path, has a measured EIRP of −4.8dBm and consumes 154mW of DC power in the OAM source mode. In the receiver mode, it has a measured conversion loss of 30dB and consumes 166mW of DC power. The output OAM beam profiles and mode orthogonality are experimentally verified and a full silicon OAM link is demonstrated.