Soil amendment in plastic greenhouse using modified biochar: soil bacterial diversity responses and microbial biomass carbon and nitrogen.

Excessive application of chemical fertilizer and continuous cropping in plastic greenhouse resulted in soil quality decline. The decrease of soil C/N ratio and the imbalance of soil carbon pool structure have brought new challenges to soil health, crop yield and sustainable agricultural development. OBJECTIVES: The experiment was set up to explore the effect of modified biochar on soil bacterial community structure, and the correlation between soil environmental factors and bacterial community structure changes. Based on the plot experiment in the field, the effect of modified biochar was studied via high-throughput MiSeq sequencing. RESULTS: Compared with the control (CK), the modified biochar (T) significantly increased soil water content, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) content and the ratio of MBC and MBN by 7.92%, 24.58%, 2.07% and 18.95%. Diversity index analysis showed that the application of modified biochar significantly increased the Shannon index, ACE index and Chao1 index of the bacterial community by 3.05%, 5.07% and 5.24%. Compared with the control, the modified biochar decreased the relative abundance of Actinobacteriota and Chloroflex by 6.81% and 2.19%, and increased the relative abundance of Proteobacteria and Acidobacteriota by 7.34% and 12.52%. Correlation analysis shows that soil bulk density and water content may be important related factors that affect bacterial community structure. CONCLUSIONS: This study provides a theoretical basis for the directional control of modified biochar in the soil microecological environment in plastic greenhouse, which is conducive to healthy and sustainable farming.

The chloroplast genome of Scutellaria franchetiana H.Lév. 1911 and its implications for phylogenetic relationships in the Scutellaria genus.

Scutellaria franchetiana H.Lév. 1911 is an important medicinal plant distributed on hillside wetlands at an altitude of 830-2300 m. The total length of complete chloroplast genome of S. franchetiana 151,852 bp of 38.37% GC content. It is a typical quadratic structure with four subregions consisting of a large single-copy region (83,894 bp), a small single-copy region (17,520 bp), and a pair of inverted repeats (25,219 bp). In the chloroplast genome of S. franchetiana, 130 genes were detected, comprising 86 protein-encoding genes, eight ribosomal RNA (rRNA) genes, and 36 transfer RNA (tRNA) genes. The comparative analysis of complete chloroplast genome sequences including 68 common genes of 27 plants indicates that S. franchetiana has a close relative relationship with Scutellaria orthocalyx and Scutellaria meehanioides. This work reported the first chloroplast genome of S. franchetiana, which provided a potential reference for studying phylogenetic relationships of the Scutellaria genus.

Biochar increases tobacco yield by promoting root growth based on a three-year field application.

In order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.

A novel serine protease inhibitor from Bungarus fasciatus venom.

By Sephadex G-50 gel filtration, cation-exchange CM-Sephadex C-25 chromatography and reversed phase high-performance liquid chromatography (HPLC), a novel serine protease inhibitor named bungaruskunin was purified and characterized from venom of Bungarus fasciatus. Its cDNA was also cloned from the cDNA library of B. fasciatus venomous glands. The predicted precursor is composed of 83 amino acid (aa) residues including a 24-aa signal peptide and a 59-aa mature bungaruskunin. Bungaruskunin showed maximal similarity (64%) with the predicted serine protease inhibitor blackelin deduced from the cDNA sequence of the red-bellied black snake Pseudechis porphyriacus. Bungaruskunin is a Kunitz protease inhibitor with a conserved Kunitz domain and could exert inhibitory activity against trypsin, chymotrypsin, and elastase. By screening the cDNA library, two new B chains of beta-bungarotoxin are also identified. The overall structures of bungaruskunin and beta-bungarotoxin B chains are similar; especially they have highly conserved signal peptide sequences. These findings strongly suggest that snake Kunitz/BPTI protease inhibitors and neurotoxic homologs may have originated from a common ancestor.

Flavobacterium anhuiense sp. nov., isolated from field soil.

A novel strain, D3T, isolated from a field-soil sample obtained from Anhui Province, PR China, was characterized taxonomically by using a polyphasic approach. The cells were Gram-negative, yellow-pigmented rods devoid of flagella, but showing gliding motility. The organism was able to grow at 5-37 degrees C and at pH 4.0-10.0. A comparative 16S rRNA gene sequence analysis indicated that strain D3T is a member of the genus Flavobacterium, sharing highest sequence similarity with the type strain of Flavobacterium defluvii (96.7 %). The major isoprenoid quinone was MK-6 and the predominant fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1 omega 7c and/or iso-C15 : 0 2-OH) and C16 : 0. The DNA G+C content was 31.4 mol%. On the basis of phylogenetic and phenotypic data, strain D3T represents a novel species within the genus Flavobacterium, for which the name Flavobacterium anhuiense sp. nov. is proposed. The type strain is D3T (=KCTC 22128T = CGMCC 1.6859T).