A strain, USTB-05, isolated from Lake Dianchi, China, degraded the cyanobacterial toxin microcystin-RR （MC-RR） at the rate of 16.7 mg/L per day. Analysis of 16S rDNA sequence showed that the strain was Sphingopyxis ...A strain, USTB-05, isolated from Lake Dianchi, China, degraded the cyanobacterial toxin microcystin-RR （MC-RR） at the rate of 16.7 mg/L per day. Analysis of 16S rDNA sequence showed that the strain was Sphingopyxis sp. Enzymatic degradation pathways for MC-RR by Sphingopyxis sp. USTB-05 were identified. Adda-Arg peptide bond of MC-RR was cleaved and then a hydrogen and a hydroxyl were combined onto the NH2 group of Adda and the carboxyl group of arginine to form a linear molecule as intermediate product within the first few hours. Then, through dehydration reaction, two hydrogen of amino group on arginine reacted with adjacent hydroxyl on carbon to form a linear MC-RR with two small peptide rings as the final product after 24 hr. These biodegradation pathways were different from those reported for other strains, implying that MC-RR may undergo different transformations and different products were formed due to various bacteria in natural lakes and reservoirs.展开更多
The plant immune system relies on a precisely balanced interplay between activation and repression to effectively combat pathogens without incurring self-damage.The salicylic acid(SA)signaling pathway,a cornerstone of...The plant immune system relies on a precisely balanced interplay between activation and repression to effectively combat pathogens without incurring self-damage.The salicylic acid(SA)signaling pathway,a cornerstone of this system,is currently experiencing a research renaissance.Landmark studies have recently elucidated the complete enzymatic pathways for SA biosynthesis from both chorismate and phenylalanine(Liu et al.,2025;Wang et al.,2025;Zhu et al.,2025),while advances in structural biology have resolved the atomic-level architecture of key signaling components(Kumar et al.,2022).展开更多
基金supported by the Chinese National Key Project for Basic Research (No.2008CB418105)the National Natural Science Foundation of China(No.20621703,20477050)the Important-Direction-Project funded by the Chinese Academy of Sciences
文摘A strain, USTB-05, isolated from Lake Dianchi, China, degraded the cyanobacterial toxin microcystin-RR （MC-RR） at the rate of 16.7 mg/L per day. Analysis of 16S rDNA sequence showed that the strain was Sphingopyxis sp. Enzymatic degradation pathways for MC-RR by Sphingopyxis sp. USTB-05 were identified. Adda-Arg peptide bond of MC-RR was cleaved and then a hydrogen and a hydroxyl were combined onto the NH2 group of Adda and the carboxyl group of arginine to form a linear molecule as intermediate product within the first few hours. Then, through dehydration reaction, two hydrogen of amino group on arginine reacted with adjacent hydroxyl on carbon to form a linear MC-RR with two small peptide rings as the final product after 24 hr. These biodegradation pathways were different from those reported for other strains, implying that MC-RR may undergo different transformations and different products were formed due to various bacteria in natural lakes and reservoirs.
基金supported by grants from the United States Department of Agriculture National Institute of Food and Agriculture(ECDRE 2022-70029-38470 and ECDRE 2025-70029-44031 to Z.M.)by a scholarship from the University of Florida Plant Molecular and Cellular Biology Program(to M.Z.).
文摘The plant immune system relies on a precisely balanced interplay between activation and repression to effectively combat pathogens without incurring self-damage.The salicylic acid(SA)signaling pathway,a cornerstone of this system,is currently experiencing a research renaissance.Landmark studies have recently elucidated the complete enzymatic pathways for SA biosynthesis from both chorismate and phenylalanine(Liu et al.,2025;Wang et al.,2025;Zhu et al.,2025),while advances in structural biology have resolved the atomic-level architecture of key signaling components(Kumar et al.,2022).
