Search

An amendment to this paper has been published and can be accessed via the original article.

BackgroundPaddy soil dissolved organic matter (DOM) represents a major hotspot for soil biogeochemistry, yet we know little about its chemodiversity let alone the microbial community that shapes it. Here, we leveraged ultrahigh-resolution mass spectrometry, amplicon, and metagenomic sequencing to characterize the molecular distribution of DOM and the taxonomic and functional microbial diversity in paddy soils across China. We hypothesized that variances in microbial community significantly associate with changes in soil DOM molecular composition.ResultsWe report that both microbial and DOM profiles revealed geographic patterns that were associated with variation in mean monthly precipitation, mean annual temperature, and pH. DOM molecular diversity was significantly correlated with microbial taxonomic diversity. An increase in DOM molecules categorized as peptides, carbohydrates, and unsaturated aliphatics, and a decrease in those belonging to polyphenolics and polycyclic aromatics, significantly correlated with proportional changes in some of the microbial taxa, such as Syntrophobacterales, Thermoleophilia, Geobacter, Spirochaeta, Gaiella, and Defluviicoccus. DOM composition was also associated with the relative abundances of the microbial metabolic pathways, such as anaerobic carbon fixation, glycolysis, lignolysis, fermentation, and methanogenesis.ConclusionsOur study demonstrates the continental-scale distribution of DOM is significantly correlated with the taxonomic profile and metabolic potential of the rice paddy microbiome. Abiotic factors that have a distinct effect on community structure can also influence the chemodiversity of DOM and vice versa. Deciphering these associations and the underlying mechanisms can precipitate understanding of the complex ecology of paddy soils, as well as help assess the effects of human activities on biogeochemistry and greenhouse gas emissions in paddy soils.

Gibberellins are a class of typical phytohormones, which regulate plant growth and development. The contents of gibberellins dramatically affect the morphology and biomass of plant. The encoding protein of copalyl diphosphate synthase gene (CPS) catalyzes the first-step in the biosynthetic pathway of gibberellins. The mutation in this gene may significantly affect the contents of gibberellins in plants. In this study, we found an EMS-triggered mutant, ga1-168, showing short roots, short hypocotyls, late flowering and dwarf. Map-based cloning revealed that the causal gene of ga1-168 was AtCPS-168, an allele of AtCPS gene. The encoding protein of AtCPS-168 was AtCPS V326M which was resulted from a single-point mutation (guanine to adenine at nucleotide 2768) of AtCPS gene. Protein domain analysis showed that V326 was located in the Terpene_synth domain. The allelism test demonstrated that AtCPS-168 was an allele of AtCPS gene. The transgenic complementation of ga1-168 indicated that AtCPS V326M led to the dwarf and bushy phenotype of ga1-168. The endogenous gibberellins contents analysis suggested that the gibberellins contents of ga1-168 were much lower than that of wild-type. The exogenous GA 3 application assay uncovered that application of GA 3 can complement the dwarf and bushy phenotype of ga1-168 caused by low endogenous gibberellins contents. Therefore, this study suggested that it is an elegant way to create the ideal plant architecture and height by site-directed mutating the gibberellin biosynthetic genes.