Analysis of rhizosphere fungal diversity in lavender at different planting years based on high-throughput sequencing technology.

Continuous cropping is a common cultivation practice in lavender cultivation, and the structure of the soil microbial community is one of the main reasons affecting the continuous cropping disorder in lavender; however, the relationship between the number of years of cultivation and inter-root microbial composition has not yet been investigated; using Illumina high-throughput sequencing we detected fungal community structure of rhizosphere soil under 1 (L1), 3 (L3), 5 (L5) and 0 (L0) years' of lavender cultivation in Yili, Xinjiang China. The results showed that with the extension of planting years, the physical-chemical characteristics of the soil shifted, and the diversity of the fungal communities shrank, the abundance and richness of species decreased and then increased, and the phylogenetic diversity increased, The structure of the soil fungal communities varied greatly. At phylum level, dominant fungal phyla were Ascomycetes, Basidiomycetes, etc. At genus level, dominant genera were Gibberella, Mortierella, etc, whose absolute abundance all increased with increasing planting years (P < 0.05); redundancy analysis showed that thesoil physicochemical characteristics significantly correlated with dominant bacterial genera. The FUN Guild prediction showed that six groups of plant pathogens and plant saprotrophs changed significantly (P < 0.05), the amount of harmful bacteria in the soil increased while the amount of arbuscular mycorrhizal fungui (AMF) decreased, leading to a continuous cropping obstacle of lavender. The findings of this study provida theoretical foundation for the management of continuous cropping and the prevention fungus-related diseases in lavender.

Insights into the functional mechanism of the non-specific lipid transfer protein nsLTP in Kalanchoe fedtschenkoi (Lavender scallops).

Plant non-specific lipid transfer protein (nsLTP) is able to bind and transport lipids and essential oils, as well as engage in various physiological processes, including defense against phytopathogens. Kalanchoe fedtschenkoi (Lavender Scallops) is an attractive and versatile succulent. To investigate the functional mechanism of Kalanchoe fedtschenkoi nsLTP (Ka-nsLTP), we expressed, purified and successfully obtained monomeric Ka-nsLTP. Mutational experiments revealed that the C6A variant retained the same activity as the wild-type (WT) Ka-nsLTP. Ka-nsLTP showed weak antiphytopathogenic bacterial activity, but inhibited fungal growth. Ka-nsLTP possessed a hydrophobic cavity effectively binding lauric acid. Our results offer novel molecular insights into the functional mechanism of nsLTP, which broadens our knowledge of the biological function of nsLTP in crops and provides a useful locus for genetic improvement of plants.

Synthesis and in†vitro Anti-Inflammatory Activity of Novel Dendrobine Amide/Sulfonamide Derivatives.

A traditional Chinese medicine ingredient, dendrobine, has been demonstrated to have anti-inflammatory properties. However, due to its poor anti-inflammatory properties, its clinical use is limited. Consequently, we have designed and synthesized 32 new amide/sulfonamide dendrobine derivatives and screened their anti-inflammatory activities in vitro. Experiments showed that nitric oxide (NO) generation in lipopolysaccharide (LPS)-induced RAW264.7 cells was strongly reduced by derivative 14, with an IC50 of 2.96 µM. Western blot research revealed that 14 decreased the concentration-dependent expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (INOS). Molecular docking was used to predict the binding of the inflammation-associated proteins COX-2 and INOS to compound 14.

Crude Lipopeptides Produced by Bacillus amyloliquefaciens Could Control the Growth of Alternaria alternata and Production of Alternaria Toxins in Processing Tomato.

Alternaria spp. and its toxins are the main contaminants in processing tomato. Based on our earlier research, the current study looked into the anti-fungal capacity of crude lipopeptides from B. amyloliquefaciens XJ-BV2007 against A. alternata. We found that the crude lipopeptides significantly inhibited A. alternata growth and reduced tomato black spot disease incidence. SEM analysis found that the crude lipopeptides could change the morphology of mycelium and spores of A. alternata. Four main Alternaria toxins were detected using UPLC-MS/MS, and the findings demonstrated that the crude lipopeptides could lessen the accumulation of Alternaria toxins in vivo and in vitro. Meanwhile, under the stress of crude lipopeptides, the expression of critical biosynthetic genes responsible for TeA, AOH, and AME was substantially down-regulated. The inhibitory mechanism of the crude lipopeptides was demonstrated to be the disruption of the mycelial structure of A. alternata, as well as the integrity and permeability of the membrane of A. alternata sporocytes. Taken together, crude lipopeptides extracted from B. amyloliquefaciens XJ-BV2007 are an effective biological agent for controlling tomato black spot disease and Alternaria toxins contamination.

Receptor-like kinases and their signaling cascades for plant male fertility: loyal messengers.

Receptor-like kinases (RLKs) are evolved for plant cell-cell communications. The typical RLK protein contains an extracellular and hypervariable N-terminus to perceive various signals, a transmembrane domain to anchor into plasma membrane, and a cytoplasmic, highly conserved kinase domain to phosphorylate target proteins. To date, RLKs have manifested their significance in a myriad of biological processes during plant reproductive growth, especially in male fertility. This review first summarizes a recent update on RLKs and their interacting protein partners controlling anther and pollen development, pollen release from dehisced anther, and pollen function during pollination and fertilization. Then, regulatory networks of RLK signaling pathways are proposed. In addition, we predict RLKs in maize and rice genome, obtain homologs of well-studied RLKs from phylogeny of three subfamilies and then analyze their expression patterns in developing anthers of maize and rice to excavate potential RLKs regulating male fertility in crops. Finally, current challenges and future prospects regarding RLKs are discussed. This review will contribute to a better understanding of plant male fertility control by RLKs, creating potential male sterile lines, and inspiring innovative crop breeding methods.

Characterization of Glycosyltransferase Family 1 (GT1) and Their Potential Roles in Anthocyanin Biosynthesis in Maize.

Glycosyltransferase family 1 (GT1) is a large group of proteins that play critical roles in secondary metabolite biosynthesis in plants. However, the GT1 family is not well studied in maize. In this study, 107 GT1 unigenes were identified in the maize reference genome and classified into 16 groups according to their phylogenetic relationship. GT1s are unevenly distributed across all ten maize chromosomes, occurring as gene clusters in some chromosomes. Collinearity analysis revealed that gene duplication events, whole-genome or segmental duplication, and tandem duplication occurred at a similar frequency, indicating that both types of gene duplication play notable roles in the expansion of the GT1 gene family. Expression analysis showed GT1s expressing in all tissues with specific expression patterns of each GT1, suggesting that they might participate in multiple biological processes during the whole growth and development stages. Furthermore, 16 GT1s were identified to have similar expression patterns to those of anthocyanidin synthase (ANS), the critical enzyme in anthocyanin biosynthesis. Molecular docking was carried out to examine the affinity of GT1s with substrates in anthocyanin biosynthesis. This study provides valuable information on the GT1s of maize and will promote the development of research on their biological functions in the biosynthesis of other secondary metabolites.

The complete mitochondrial genome of the Xinyuan honey bee, Apis mellifera sinisxinyuan (Insecta: Hymenoptera: Apidae).

We analyzed the complete mitochondrial genome of the recently discovered Xinyuan honey bee, Apis mellifera sinisxinyuan using single molecule real-time sequencing. The mitochondrial genome of A. m. sinisxinyuan is a circular molecule of 16,886 bp, comprising 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region rich in A + T. Phylogenetic analysis using 13 protein-coding genes supports a close relationship to another M-lineage honey bee, A. m. mellifera.

Effects of Different Temperatures on the Chemical Structure and Antitumor Activities of Polysaccharides from Cordyceps militaris.

The effects of different extraction temperatures (4 and 80 °C) on the physicochemical properties and antitumor activity of water soluble polysaccharides (CMPs-4 and CMPs-80) from Cordyceps militaris (C. militaris) were evaluated in this study. The results of gas chromatography (GC) and high-performance gel permeation chromatography (HPGPC) showed that a higher extraction temperature could degrade the polysaccharides with 188 kDa, mainly composed of glucose, and increase the dissolution rate of polysaccharides about 308 kDa, mainly consisting of rhamnose and galactose. In addition, the CMPs displayed the same sugar ring and category of glycosidic linkage based on Fourier-transform infrared spectroscopy (FTIR) analysis, however, their invisible structural difference occurred in the specific rotation and conformational characteristics according to the results of specific optical rotation measurement and Congo red test. In vitro antitumor experiments indicated that CMPs-4 possessed stronger inhibitory effects on human esophagus cancer Eca-109 cells by inducing cell apoptosis more than CMPs-80 did. These findings demonstrated that the polysaccharides extracted with cold water (4 °C) could be applied as a novel alternative chemotherapeutic agent or dietary supplement with its underlying antitumor property.

[Demography and spectrum analysis of Juglans cathayensis populations at different altitudes in the west Tianshan valley in Xinjiang, China].

Juglans cathayensis is an endangered plant species and listed as a class II protected species of the national government of China. In order to grasp the current state of J. cathayensis populations and predict the population dynamics in the future, a large-sample investigation was conducted in the sample plots along different altitude gradients in four valleys in J. cathayensis conservation area. According to the diameter at breast height (DBH) class of the trees, the age class structures of the populations were analyzed, and static life tables for J. cathayensis populations in different habitats along the altitude gradient was constructed by smoothing out technique, and comparative fluctuations cycles of the populations in different habitats were carried out by spectral analysis. The results showed that DBH decreased gradually with the increasing altitude. The population was composed of 19 age classes in the low-altitude habitat (1241 - 1380 m) with the maximum DBH of 91.7 cm, 18 age classes in the middle-altitude habitat (1381 - 1490 m) with the maximum DBH of 82.8 cm, and 13 age classes in the high-altitude habitat (1491 - 1670 m) with the maximum DBH of 58.9 cm. Life expectancies of J. cathayensis populations were fluctuant for the same age class at different altitudes and for different age classes at the same altitude. In the three altitude-different habitats, the survival curves of the populations trended toward Deevey- II type and the age structures of the populations were expanding. The curves of mortality showed three peaks, and the mortality rates of 9 age classes at 1241 - 1380 m and 1491 - 1670 m above sea levels were the highest, being 55.9% and 89.8%, respectively, and the mortality rate of 12 age classes at 1381 - 1490 m above sea level was the highest (79.4%). The population dynamics was significantly affected by the fundamental wave of biological characteristic throughout the life cycle of J. cathayensis population, and small cycles of multi-harmonic superposition with large cycles were presented. J. cathayensis is a long lifespan tree and a major dominant species in this conservation area. The natural regeneration of its current populations is good. If not strong anthropogenic disturbances or severe natural disasters, J. cathayensis would maintain the dominant position in the community.

Disruption of gene pqqA or pqqB reduces plant growth promotion activity and biocontrol of crown gall disease by Rahnella aquatilis HX2.

Rahnella aquatilis strain HX2 has the ability to promote maize growth and suppress sunflower crown gall disease caused by Agrobacterium vitis, A. tumefaciens, and A. rhizogenes. Pyrroloquinoline quinone (PQQ), a cofactor of aldose and alcohol dehydrogenases, is required for the synthesis of an antibacterial substance, gluconic acid, by HX2. Mutants of HX2 unable to produce PQQ were obtained by in-frame deletion of either the pqqA or pqqB gene. In this study, we report the independent functions of pqqA and pqqB genes in relation to PQQ synthesis. Interestingly, both the pqqA and pqqB mutants of R. aquatilis eliminated the ability of strain HX2 to produce antibacterial substance, which in turn, reduced the effectiveness of the strain for biological control of sunflower crown gall disease. The mutation also resulted in decreased mineral phosphate solubilization by HX2, which reduced the efficacy of this strain as a biological fertilizer. These functions were restored by complementation with the wild-type pqq gene cluster. Additionally, the phenotypes of HX2 derivatives, including colony morphology, growth dynamic, and pH change of culture medium were impacted to different extents. Our findings suggested that pqqA and pqqB genes individually play important functions in PQQ biosynthesis and are required for antibacterial activity and phosphorous solubilization. These traits are essential for R. aquatilis efficacy as a biological control and plant growth promoting strain. This study enhances our fundamental understanding of the biosynthesis of an environmentally significant cofactor produced by a promising biocontrol and biological fertilizer strain.

Draft genome sequence of Rahnella aquatilis strain HX2, a plant growth-promoting rhizobacterium isolated from vineyard soil in Beijing, China.

Rahnella aquatilis strain HX2 is a plant growth-promoting, disease-suppressive rhizobacterium that was isolated from a vineyard soil in Beijing, China. Here, we report the genome sequence of this strain, which provides a valuable resource for future research examining the mechanisms of traits associated with plant growth promotion and biocontrol.