Lr34/Yr18/Sr57/Pm38 confers broad-spectrum resistance to fungal diseases via transport of sinapyl alcohol for cell wall lignification in wheat.

Widely known pleiotropic adult plant resistance (PAPR) gene, Lr34 encodes an ATP-binding cassette transporter and plays an important role in breeding wheat for enhancing resistance against multiple fungal diseases. Despite its recognized significance, the mechanism underlying Lr34 in pathogen defense remains largely elusive. Our study demonstrated that wheat lines harboring the Lr34res allele exhibit thicker cell walls and enhanced resistance to fungal penetration compared to lines lacking Lr34res. Transcriptome and metabolite profiling revealed that the lignin biosynthetic pathway was repressed in lr34 mutants, indicating a disruption in cell wall lignification. Furthermore, our investigation uncovered the hypersensitivity of lr34 mutant lines to sinapyl alcohol, a major monolignol crucial for cell wall lignification. Yeast accumulation and efflux assays confirmed that Lr34 protein functions as a sinapyl alcohol transporter. Both genetic and virus-induced gene silencing (VIGS) experiments revealed that the disease resistance conferred by Lr34 could be enhanced with the addition of the TaCOMT-3B gene, which is responsible for biosynthesis of sinapyl alcohol. Collectively, our findings provide novel insights into the role of Lr34 in disease resistance, through mediating sinapyl alcohol transport and cell wall deposition. Moreover, TaCOMT-3B plays a synergistic role in the Lr34 facilitated defensive lignification in adult wheat plants against multiple fungal pathogens.

The first case of Escherichia fergusonii with biofilm in China and literature review.

BACKGROUND: Escherichia fergusonii is a rare opportunistic pathogen in humans and animals, especially with biofilm. METHODS: In one case, E. fergusonii with biofilm was detected in the bile, and silver staining was used to prove it had biofilm. The clinical characteristics and drug susceptibility of eight cases of E. fergusonii retrieved from the literature were also summarized. RESULTS: This is a case of E. fergusonii with biofilm, which has not been reported in China. The 8 cases retrieved from the literature did not specify whether they had biofilm, but we analyzed their clinical characteristics and drug susceptibility. All patients were treated with antimicrobial drugs. 8 cases showed sensitivity to piperacillin/tazobactam and imipenem in 6 cases (75%), but poor sensitivity to levofloxacin and ciprofloxacin. CONCLUSION: The silver staining method proved biofilm in this case, which is the first case of E. fergusonii with biofilm in China.

Production of Conjoined Transgenic and Edited Barley and Wheat Plants for Nud Genes Using the CRISPR/SpCas9 System.

The Nudum (Nud) gene controls the caryopsis type of cereal crops by regulating lipid biosynthetic pathways. Based on the HvNud sequence and its homologous gene sequences in wheat, a conserved sgRNA was designed to obtain the mutants from the barley variety "Vlamingh" and the wheat variety "Fielder" via Agrobacterium-mediated transformation. A total of 19 and 118 transgenic plants were obtained, and 11 and 61 mutant plants were identified in T0 transgenic plants in barley and wheat after PCR-RE detection, and the editing efficiencies of the targeted gene were 57.9 and 51.7% in barley and wheat, respectively. The grain shape of the barley mutants was naked. Five different combinations of mutations for wheat TaNud genes were identified in the T0 generation, and their homozygous-edited plants were obtained in the T1 generation. Interestingly, the conjoined plants in which one plant has different genotypes were first identified. The different tillers in an individual T0 plant showed independent transgenic or mutant events in both barley and wheat, and the different genotypes can stably inherit into T1 generation, indicating that the T0 transgenic plants were the conjoined type. In addition, we did not find any off-target mutations in both barley and wheat. A candidate method for detecting putative-edited wheat plants was suggested to avoid losing mutations in this investigation. This study provides not only materials for studying the function of the Nud gene in barley and wheat but also a system for detecting the mutants in wheat.

Volatile Composition in Two Pummelo Cultivars (Citrus grandis L. Osbeck) from Different Cultivation Regions in China.

This study investigated the composition of volatile compounds in two pummelo cultivars, including 'Shatian' and 'Guanxi', cultivated in different regions of China with the aim of studying the effect of cultivar and cultivation condition on biosynthesis of volatile compounds in pummelo. Volatile compounds were extracted from pummelo juice using head-space microextraction and then analyzed using gas chromatography coupled with mass spectrometry. Results showed that a total of 49 volatile compounds was detected in the study, including 11 aldehydes, 7 alcohols, 3 ketones, 7 esters, 19 terpenes and 2 other volatiles. The 'Guanxi' pummelo cultivar possessed a more complex composition of volatile compounds compared with the 'Shatian' cultivar. Meanwhile, the volatile compounds appeared to exhibit a higher concentration in the 'Guanxi' cultivar samples than the 'Shatian' cultivar. Cluster analysis revealed that the 'Guanxi' cultivar samples from the different regions were grouped together, whereas the 'Shatian' cultivar samples were assembled. Principal component analysis showed that an obvious separation was observed between the 'Guanxi' and 'Shatian' cultivar. However, the 'Shatian-SC15' was significantly separated from the other 'Shatian' cultivar samples. These indicated that cultivar genotype was the primary factor that determined the volatile profile of the pummelo cultivar. Cultivation region might affect the biosynthesis of volatile compounds, resulting in the differentiation of the volatile composition in each pummelo cultivar.