Soil microorganisms are involved in the litter decomposition process and are closely related to nutrient cycling in ecosystems, especially carbon (C) and nitrogen (N) cycling. For grassland ecosystems, most grassland biomass is invested in the root system. Therefore, to determine the influence of root decomposition on soil microorganisms in different grassland species, an in‐situ root decomposition experiment was conducted with two species (gramineous forage: Bothriochloa ischaemum and leguminous forage: Lespedeza davurica) over three decomposition times (90, 270 and 450 days). Total organic carbon (TOC) and total nitrogen (TN) in the roots of the two species decreased gradually. And L. davurica had higher soil organic carbon (SOC) and soil total nitrogen (STN) in the late stage. Proteobacteria, Chloroflexi and Acidobacteria were the dominant bacteria, and Ascomycota and Basidiomycota were the dominant fungi in the two species. STN is the most important factor driving changes in soil microbial communities. The alpha diversity index of bacteria in both species showed an increasing trend, while in fungi, it decreased rapidly at the early stage and increased slightly at the late stage. Compared with the bacteria in B. ischaemum, L. davurica increased some submetabolic system pathway genes related to carbon cycle metabolism. FUNGuild revealed that saprotrophic fungi on the 90th day were significantly lower than those on the 270th and 450th days. Our results show that leguminous forages have better performance in improving SOC and STN, and microbial characteristics are also affected by species during root decomposition.

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Leaves are an essential and unique organ of plants, and many studies have proved that auxin has significant impacts on the architecture of leaves, thus the manipulation of the three-dimensional structure of a leaf could provide potential strategies for crop yields. In this study, 32 basic leucine zipper transcription factors (bZIP TFs) which responded to 50 μM of indole-acetic acid (IAA) were identified in wheat leaves by transcriptome analysis. Phylogenetic analysis indicated that the 32 auxin-responsive TabZIPs were classified into eight groups with possible different functions. Phenotypic analysis demonstrated that knocking out the homologous gene of the most down-regulated auxin-responsive TabZIP6D_20 in Arabidopsis (AtHY5) decreased its sensitivity to 1 and 50 μM IAA, while the TabZIP6D_20/hy5 complementary lines recovered its sensitivity to auxin as a wild type (Wassilewskija), suggesting that the down-regulated TabZIP6D_20 was a negative factor in the auxin-signaling pathway. These results demonstrated that the auxin-responsive TabZIP genes might have various and vital functions in the architecture of a wheat leaf under auxin response.