The ecosystem of tea plantations portrays a special interaction among environment, soil microorganisms and tea trees. Under the influence of environmental factors and human management, the growth, quality, yield of tea trees and the tea leaves may also be dependent upon the changes in the soil microbial community. However, little is known about the composition and structure of soil bacterial and fungal communities in hundred-year-old tea plantations and the mechanisms by which they are affected. In this regard, we characterized the microbiome of tea plantation soils by considering the bacterial and fungal communities in 448 soil samples from 101 ancient tea plantations in eight counties of Lincang city, which is one of domestication centers of tea trees in the world. We applied 16S and ITS rRNA high-throughput sequencing techniques, and found that the effect of pH and altitude changes on the relative abundance of fungal communities was more pronounced than that on bacteria. In terms of the influence of pH and altitude on soil microbial communities, the abundance and diversity of bacterial communities were more sensitive to pH than those of fungi. The α-diversity of bacterial communities peaked in the pH 4.50-5.00 and altitude 2,200 m group, and the highest α-diversity of fungi showed in the pH 5.00-5.50 and 900 m group. While all microbes varied similarly changing with environment and geographies, and further correlations were found that the composition and structure of bacterial communities were more sensitive to latitude and altitude than that of fungal communities.

Abstract：Sophora tonkinensis (shandougen) is a woody leguminous plant widely known for its medicinal values in China. The genome of various legumes utilized as reference genetic maps for pseudomolecule assembly have been published. However, the genome of Sophora has not been mapped. In this study, we reported a chromosomal scale draft genome of S. tonkinensis assembled using PacBio single-molecule real-time sequencing reads and Hi-C technique. A high-quality draft S. tonkinensis genome of 899Mb in size was obtained, which was larger than those of some other leguminous genome, and the BUSCO analysis reviewed 95.9% completeness of the genome. We annotated 78.3% of the genome as repeat elements and transposable elements occupied 73%. A total of 36,410 protein-coding genes were identified in the S. tonkinensis genome. The comparative analysis on genome size and repetitive sequences of S. tonkinensis and four other legumes (Lupinus albus, Lupinus angustifolius, Glycyrrhiza uralensis and Medicago truncatula) revealed that the transposable elements (TEs) in S. tonkinensis were inserted after the whole genome duplication and after differentiation with other legumes. It can be speculated that the size of the S. tonkinensis genome may be related to the repetitive sequence insertion. We also analyzed matrine and flavonoids which are important compounds in S. tonkinensis. We further analyzed lignin and Nitrogen-fixing gene which plays an important role in the adaptation of S. tonkinensis to the environment. In conclusion, the high-quality genome of S. tonkinensis obtained in this study laid the foundation for genetic and molecular biology studies of legumes.