Project description:High toxin (HT) producing and a low toxin producing (LT) strains of Karenia brevis both derived from the Wilson strain.
Samples were labeled with TMT11 plex, and fractionated into 8 fractions (ECL1_1191562 to 1191569).
HT was labeled with 126, 127N, 127C, 128N, 129N.
LT was labeled with 128C, 129C, 130C, 130N, 131N.
Project description:Alternaria, a widespread fungal genus, infects a wide range of crops and produces various toxins, such as Tentoxin (TEN), Tenuazonic acid (TeA), Alternariol (AOH) during infection, leading to a major concern about safety of these crops. Although the toxin-producing ability varies among different Alternaria species, the underlying mechanisms are still unclear. In this study, several Alternaria toxins were frequently detected in Tibetan barley (Hordeum vulgare var. coeleste Linnaeus) and wheat (Triticum aestivum Linn) in Tibet, especially TEN and TeA, which were detected in half of the crops. 153 barley and wheat samples collected from 5 different regions in Tibet were used for toxin detection/quantification, isolation and identification of the corresponding toxin producing fungi. According to levels of toxins produced in vivo, different isolates of Alternaria alternaria recovered from the above collected sampled were divided into three groups designated as high toxin-producing strains (HT), medium toxin-producing strains (LT) and no toxin-producing strains (NT). Metabolomics and transcriptomics were employed to investigate the potential mechanism of variations in toxin production among different isolates. Metabolomics analysis revealed high levels of amino acids and secondary metabolites in HT. Various precursors of TeA/TEN were also highly accumulated in HT, especially isoleucine ( which was one of essential gradients of TEN biosynthesis, which may account for high toxin production in HT strains in metabolome. Further transcriptome analysis revealed that the expression levels of genes relevant to precursors of TEN/TeA were higher in HT, especially CC77DRAFT_360136, CC77DRAFT_546209, CC77DRAFT_1033655 and CC77DRAFT_1090532, showing the molecular basis for toxin-producing variations among three strains. Importantly, our topological regulation network results identified the candidate genes that regulated these four genes involved in toxin-producing, and these genes may be essential for variations in toxin producing ability of these Alternaria strains. Overall, this comprehensive analysis expects to provide a better understanding to decipher the mechanism of toxicity based on molecular and metabolic levels.
