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Residual antibiotics can enter soil and water bodies through organic fertilizers with food safety risk via plants absorption, while how do plant growth and quinolone accumulation respond to residual antibiotics levels in soil or water is not clear. Hydroponic experiment in greenhouse was conducted with floating seedlings of tobacco as model plant to investigate the responses of quinolone antibiotics accumulation and plant growth to different levels of ciprofloxacin (CIP) and norfloxacin (NOR). Results showed that CIP and NOR inhibited the growth of tobacco seedlings. The plant height, stem circumference, maximum leaf width, and maximum leaf area of tobacco seedlings were significantly decreased. So as to the plant biomass of leaves, stems, and roots. Accumulation of CIP in the tobacco seedlings in the T3 was 1.1 times that of the tobacco seedlings in the T1, NOR in the T4 was 1.2 times that of the tobacco seedlings in the T1. And the higher the concentration, the more significant the inhibitory effect. Both antibiotics can be absorbed and accumulated by tobacco seedlings. Additionally, the inhibitory effect of CIP was greater than that of NOR.

Cadmium (Cd) of tobacco is a pollutant that is extremely toxic to the health of humans. Protein plant cadmium resistance 8 gene has been characterized to increase the plant Cd resistance. In present experiment, the complete mRNA sequence of tobacco protein plant cadmium resistance 8 gene was amplified using the rapid amplification of cDNA ends methods. The full-length tobacco protein plant cadmium resistance 8 gene mRNA was 887bp containing an 555 bp open reading frame, which encodes a protein of 184 amino acids. BLAST analysis revealed that tobacco protein plant cadmium resistance 8 protein shares high homology with the protein plant cadmium resistance 8 of potato (81%), Lycopersicon esculentum (80%), Eutrema salsugineum (60%), Capsella rubella (58%) and thale cress (57%). Results also showed that tobacco protein plant cadmium resistance 8 gene has a closer genetic relationship with the protein plant cadmium resistance 8 gene of Lycopersicon esculentum. The expression profile was studied and the results indicated that tobacco protein plant cadmium resistance 8 gene was highly expressed in root, moderately expressed in stem, and hardly expressed in flower and leaf. These results established the primary foundation of utilizing tobacco protein plant cadmium resistance 8 gene to decrease the cadmium content of tobacco and benefit the health of humans in the future.

The complete mRNA sequence of one tobacco (Nicotiana tabacum) gene- apoplastic invertase, was amplified using the rapid amplification of cDNA ends methods based on some tobacco ESTs. The full-length tobacco apoplastic invertase gene mRNA was 1,985bp containing an 1,740 bp open reading frame, which encodes a protein of 579 amino acids. Sequence analysis revealed that the apoplastic invertase of tobacco shares high homology with the apoplastic invertase of potato (82%), Lycopersicon esculentum (81%) and Lycopersicon pennellii (78%). Results also showed that tobacco apoplastic invertase gene has a closer genetic relationship with the apoplastic invertase gene of Lycopersicon esculentum. The prediction of transmembrane helices showed that tobacco apoplastic invertase might be a transmembrane protein. The expression profile was studied and the results indicated that tobacco apoplastic invertase gene was differentially expressed in detected tobacco tissues including leaf, stem, root and flower. Our experiment established the foundation for further research on this tobacco gene.

• Overexpression of AtCPC reduced flavonoid accumulation and promoted lignin synthesis. • Overexpression of RrFLS or RrANR up-regulated lignin biosynthesis in tobacco. • A novel insight into homeostatic regulation of flavonoid and lignin biosynthesis. Flavonoids and lignin consist of a large number of secondary metabolites which are derived from the phenylpropanoid pathway, and they act as a significant role in plant growth, development, and stress response. However, few reports have documented that how different subbranches of phenylpropanoid metablolic pathway mutually interact. In Arabidopsis , AtCPC (AtCAPRICE) is known to play a negative role in anthocyanin accumulation. Nonetheless, whether AtCPC could control the biosynthesis of lignin is largely unknown. Additionally, whether the RrFLS and RrANR, flavonol synthase and anthocyanidin reductase, from Rosa rugosa regulate different branches of phenylpropanoid pathway is unclear. Here, we performed a series of transgenic experiments with short life cycle tobacco and RNA-Seq analysis. Finally, a series of assays related to biological, physiological, and phenotypic characteristics were undertaken. Our results indicated that ectopic expression of AtCPC in tobacco not only decreased the flavonoid compound accumulation, but also up-regulated several lignin biosynthetic genes, and significantly increased the accumulation of lignin. Our results also revealed that although they respectively improved the flavonol and proanthocyanidin contents, the overexpression of RrFLS and RrANR plays positive roles in lignin biosynthesis in transgenic tobacco plants. Our findings provide a novel insight into the mechanism underlying homeostatic regulation of flavonoid and lignin biosynthesis in phenylpropanoid pathway of plants. [ABSTRACT FROM AUTHOR]

Introduction: Changes in the rhizosphere microbiome and metabolites resulting from crop intercropping can significantly enhance crop growth. While there has been an increasing number of studies on various crop combinations, research on the intercropping of tobacco and maize at seedling stage remains limited., Methods: This study is the first to explore rhizosphere effects of intercropping between tobacco and maize seedling stages, we analyzed the nitrogen, phosphorus and potassium nutrients in the soil, and revealed the important effects on soil microbial community composition and metabolite profiles, thereby regulating crop growth and improving soil balance., Results and Discussion: Compared with mono-cropping, intercropping increased the biomass of the two crops and promoted the nutrient absorption of nitrogen, phosphorus and potassium. Under intercropping conditions, the activities of sucrase, catalase and nitrate reductase in tobacco rhizosphere soil and the content of available potassium, the activities of nitrate reductase and acid phosphatase in maize rhizosphere soil were significantly increasing. Rhizosphere soil bacterial and fungal communities such as Sphingomonas, Massilia, Humicola and Penicillium respond differently to crop planting patterns, and soil dominant microbial communities are regulated by environmental factors such as pH, Organic Matter, Available Potassium, Nitrate Reductase, and Urease Enzyme. Network analysis showed that soil microbial communities were more complex after intercropping, and the reciprocal relationship between bacteria and fungi was enhanced. The difference of metabolites in soil between intercropping and monocropping system was mainly concentrated in galactose metabolism, starch and sucrose metabolism pathway, and the content of carbohydrate metabolites was significantly higher than that of monocropping soil. Key metabolites such as D-Sucrose, D-Fructose-6-Phosphate, D-Glucose-1-Phosphatel significantly influence the composition of dominant microbial communities such as Sphingomonas and Penicillium. This study explained the effects of intercropping between flue-cured tobacco and maize on the content of soil metabolites and soil microbial composition in rhizosphere soil, and deepened the understanding that intercropping system can improve the growth of flue-cured crops seedlings through rhizosphere effects., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ma, Liu, Zhao, Dou, Yang, Liu, Nian, Tong, Li, Xu, Zhang, Zhang, Li, Deng and Liu.)

Numerous bacteria, fungi and other microorganisms in the tobacco phyllosphere interstellar area participate in the physiological metabolism of plants by interacting with the host. However, there is currently little research on the characteristics of tobacco phyllosphere microbial communities, and the correlation between tobacco phyllosphere microbial communities and phyllosphere factor indicators is still unknown. Therefore, high-throughput sequencing technology based on the 16S rRNA/ITS1 gene was used to explore the diversity and composition characteristics of tobacco phyllosphere bacterial and fungal communities from different maturation processes, and to identify marker genera that distinguish phyllosphere microbial communities. In this study, the correlations between tobacco phyllosphere bacterial and fungal communities and the precursors of major aroma compounds were explored. The results showed that as the tobacco plants matured, the density of glandular trichomes on the tobacco leaves gradually decreased. The surface physicochemical properties of tobacco leaves also undergo significant changes. In addition, the overall bacterial alpha diversity in the tobacco phyllosphere area increased with maturation, while the overall fungal alpha diversity decreased. The beta diversity of bacteria and fungi in the tobacco phyllosphere area also showed significant differences. Specifically, with later top pruning time, the relative abundances of Acidisoma , Ralstonia , Bradyrhizobium , Alternaria and Talaromyces gradually increased, while the relative abundances of Pseudomonas , Filobassidium , and Tausonia gradually decreased. In the bacterial community, Acidisoma , Ralstonia , Bradyrhizobium , and Alternaria were significantly positively correlated with tobacco aroma precursors, with significant negative correlations with tobacco phyllosphere trichome morphology, while Pseudomonas showed the opposite pattern; In the fungal community, Filobasidium and Tausonia were significantly negatively correlated with tobacco aroma precursors, and significantly positively correlated with tobacco phyllosphere trichome morphology, while Alternaria showed the opposite pattern. In conclusion, the microbiota (bacteria and fungi) and aroma precursors of the tobacco phyllosphere change significantly as tobacco matures. The presence of Acidisoma , Ralstonia , Bradyrhizobium and Alternaria in the phyllosphere microbiota of tobacco may be related to the aroma precursors of tobacco., Competing Interests: Author YH, YZ, SW, T’EX, TW, and HD were employed by the company Technology and Research Center, Lincang Branch Company of Yunnan Tobacco Company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Shi, He, Zheng, Liu, Wang, Xiong, Wen, Duan, Liao, Cui and Nian.)

Rhizosphere microbiota play an important role in regulating soil physical and chemical properties and improving crop production performance. This study analyzed the relationship between the diversity of rhizosphere microbiota and the yield and quality of flue-cured tobacco at different transplant times (D30 group, D60 group and D90 group) and in different regions [Linxiang Boshang (BS) and Linxiang ZhangDuo (ZD)] by high-throughput sequencing technology. The results showed that there were significant differences in the physicochemical properties and rhizosphere microbiota of flue-cured tobacco rhizosphere soil at different transplanting times, and that the relative abundance of Bacillus in the rhizosphere microbiota of the D60 group was significantly increased. RDA and Pearson correlation analysis showed that Bacillus , Streptomyces and Sphingomonas were significantly correlated with soil physical and chemical properties. PIGRUSt2 function prediction results showed that compared with the D30 group, the D60 group had significantly increased metabolic pathways such as the superpathway of pyrimidine deoxyribonucleoside salvage, allantoin degradation to glyoxylate III and pyrimidine deoxyribonucleotides de novo biosynthesis III metabolic pathways. The D90 group had significantly increased metabolic pathways such as ubiquitol-8 biosynthesis (prokaryotic), ubiquitol-7 biosynthesis (prokaryotic) and ubiquitol-10 biosynthesis (prokaryotic) compared with the D60 group. In addition, the yield and quality of flue-cured tobacco in the BS region were significantly higher than those in the ZD region, and the relative abundance of Firmicutes and Bacillus in the rhizosphere microbiota of flue-cured tobacco in the BS region at the D60 transplant stage was significantly higher than that in the ZD region. In addition, the results of the hierarchical sample metabolic pathway abundance map showed that the PWY-6572 metabolic pathway was mainly realized by Paenibacillus , and that the relative abundance of flue-cured tobacco rhizosphere microbiota ( Paenibacillus ) participating in PWY-6572 in the D60 transplant period in the BS region was significantly higher than that in the ZD region. In conclusion, different transplanting periods of flue-cured tobacco have important effects on soil physical and chemical properties and rhizosphere microbial communities. There were significant differences in the rhizosphere microbiota and function of flue-cured tobacco in different regions, which may affect the performance and quality of this type of tobacco., Competing Interests: YH, YZ, YX, SS, MF, SG, GL, WT, and JW were employed by Lincang Branch Company of Yunnan Tobacco Company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhao, He, Zheng, Xu, Shi, Fan, Gu, Li, Tianli, Wang, Li, Deng, Liao, Du and Nian.)

Phytophthora parasitica is an important oomycete that causes disease in a variety of plants, dimethomorph fungicides being specific for oomycetes. The aim of this study was to use RNA-seq to rapidly discover the mechanism by which dimethomorph acts in the treatment of P. parasitica. We found that the expression of 832 genes changed significantly after the dimethomorph treatment, including 365 up-regulated genes and 467 down-regulated genes. According to the Gene Ontology (GO) enrichment analysis, pathway enrichment and verification test results, the following conclusions are obtained: (i) the treatment of P. parasitica with dimethomorph causes changes in the expression levels of genes associated with the cell wall and cell wall synthesis; (ii) dimethomorph treatment results in reduced permeability of the cell membrane and changes in the expression of certain transport-related proteins; (iii) dimethomorph treatment increased reactive oxygen species and reduced the expression of genes related to the control of oxidative stress., (Copyright © 2018 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

High yield is the most important goal in crop breeding, and boron (B) is an essential micronutrient for plants. However, B deficiency, leading to yield decreases, is an agricultural problem worldwide. Brassica napus is one of the most sensitive crops to B deficiency, and considerable genotypic variation exists among different cultivars in response to B deficiency. To dissect the genetic basis of tolerance to B deficiency in B. napus, we carried out QTL analysis for seed yield and yield-related traits under low and normal B conditions using the double haploid population (TNDH) by two-year and the BQDH population by three-year field trials. In total, 80 putative QTLs and 42 epistatic interactions for seed yield, plant height, branch number, pod number, seed number, seed weight and B efficiency coefficient (BEC) were identified under low and normal B conditions, singly explaining 4.15-23.16% and 0.53-14.38% of the phenotypic variation. An additive effect of putative QTLs was a more important controlling factor than the additive-additive effect of epistatic interactions. Four QTL-by-environment interactions and 7 interactions between epistatic interactions and the environment contributed to 1.27-4.95% and 1.17-3.68% of the phenotypic variation, respectively. The chromosome region on A2 of SYLB-A2 for seed yield under low B condition and BEC-A2 for BEC in the two populations was equivalent to the region of a reported major QTL, BE1. The B. napus homologous genes of Bra020592 and Bra020595 mapped to the A2 region and were speculated to be candidate genes for B efficiency. These findings reveal the complex genetic basis of B efficiency in B. napus. They provide a basis for the fine mapping and cloning of the B efficiency genes and for breeding B-efficient cultivars by marker-assisted selection (MAS).