Search

Rhizoctonia solani is a devastating soil-borne pathogen that seriously threatens the cultivation of economically important crops. Multiple strains with a very broad host range have been identified, but only 1 (AG1-IA, which causes rice sheath blight disease) has been examined in detail. Here, we analyzed AG4-HGI 3 originally isolated from Tartary buckwheat (Fagopyrum tataricum), but with a host range comparable to AG1-IA. Genome comparison reveals abundant pathogenicity genes in this strain. We used multiomic approaches to improve the efficiency of screening for disease resistance genes. Transcriptomes of the plant–fungi interaction identified differentially expressed genes associated with virulence in Rhizoctonia and resistance in Tartary buckwheat. Integration with jasmonate-mediated transcriptome and metabolome changes revealed a negative regulator of jasmonate signaling, cytochrome P450 (FtCYP94C1), as increasing disease resistance probably via accumulation of resistance-related flavonoids. The integration of resistance data for 320 Tartary buckwheat accessions identified a gene homolog to aspartic proteinase (FtASP), with peak expression following R. solani inoculation. FtASP exhibits no proteinase activity but functions as an antibacterial peptide that slows fungal growth. This work reveals a potential mechanism behind pathogen virulence and host resistance, which should accelerate the molecular breeding of resistant varieties in economically essential crops. Multiomic association analysis dissects the genetic basis of the virulence mechanism in Rhizoctonia solani and the jasmonic acid–mediated resistance against R. solani in Tartary buckwheat. [ABSTRACT FROM AUTHOR]

Seed aging is the gradual decline in seed vigor, during which programmed cell death (PCD) occurs. The functions of nitric oxide (NO) are exerted through protein S -nitrosylation, a reversible post-translational modification. During seed aging, more than 80 proteins are S -nitrosylated, but the particular role of individual proteins is unknown. Here, we showed that the S -nitrosylation level of glyceraldehyde 3-phosphate dehydrogenase (UpGAPDH) in elm (Ulmus pumila L.) seeds increased after controlled deterioration treatment. UpGAPDH was S -nitrosylated at Cys154 during S -nitrosoglutathione (GSNO) treatment, and its oligomerization was triggered both in vitro and in elm seeds. Interestingly, UpGAPDH interacted with the mitochondrial voltage-dependent anion channel in an S -nitrosylation-dependent way. Some UpGAPDH–green fluorescent protein in Arabidopsis protoplasts co-localized with mitochondria during the GSNO treatment, while the S -nitrosylation-defective UpGAPDH C154S–GFP protein did not. Seeds of oxUpGAPDH lines showed cell death and lost seed vigor rapidly during controlled deterioration treatment-triggered seed aging, while those overexpressing S -nitrosylation-defective UpGAPDH-Cys154 did not. Our results suggest that S -nitrosylation of UpGAPDH may accelerate cell death and seed deterioration during controlled deterioration treatment. These results provide new insights into the effects of UpGAPDH S -nitrosylation on protein interactions and seed aging. [ABSTRACT FROM AUTHOR]

Seed ageing is a major problem in the conservation of germplasm resources. The involvement of possible signalling molecules during seed deterioration needs to be identified. In this study, we confirmed that nitric oxide (NO), a key signalling molecule in plants, plays a positive role in the resistance of elm seeds to deterioration. To explore which metabolic pathways were affected by NO, an untargeted metabolomic analysis was conducted, and 163 metabolites could respond to both NO and the ageing treatment. The primary altered pathways include glutathione, methionine, and carbohydrate metabolism. The genes involved in glutathione and methionine metabolism were up-regulated by NO at the transcriptional level. Using a biotin switch method, proteins with an NO-dependent post-translational modification were screened during seed deterioration, and 82 putative S -nitrosylated proteins were identified. Eleven of these proteins were involved in carbohydrate metabolism, and the activities of the three enzymes were regulated by NO. In combination, the results of the metabolomic and S -nitrosoproteomic studies demonstrated that NO could activate glycolysis and inhibit the pentose phosphate pathway. In summary, the combination of these results demonstrated that NO could modulate carbohydrate metabolism at the post-translational level and regulate glutathione and methionine metabolism at the transcriptional level. It provides initial insights into the regulatory mechanisms of NO in seed deterioration. [ABSTRACT FROM AUTHOR]

The process of domestication has led to dramatic differences in behavioral traits between domestic dogs and gray wolves. Whole-genome research found that a class of putative positively selected genes were related to various aspects of learning and memory, such as long-term potentiation and long-term depression. In this study, we constructed a single-nucleus transcriptomic atlas of the dog hippocampus to illustrate its cell types, cell lineage and molecular features. Using the transcriptomes of 105 057 nuclei from the hippocampus of a Beagle dog, we identified 26 cell clusters and a putative trajectory of oligodendrocyte development. Comparative analysis revealed a significant convergence between dog differentially expressed genes (DEGs) and putative positively selected genes (PSGs). Forty putative PSGs were DEGs in glutamatergic neurons, especially in Cluster 14, which is related to the regulation of nervous system development. In summary, this study provides a blueprint to understand the cellular mechanism of dog domestication. [ABSTRACT FROM AUTHOR]