摘要：
Ramie (Boehmeria nivea [L.] Gaud.), a nutritious animal feed, is rich in protein and produces a variety of secondary metabolites that increase its palatability and functional composition. Ethylene (ETH) is an important plant hormone that regulates the growth and development of various crops. In this study, we investigated the impact of ETH sprays on the growth and metabolism of forage ramie. We explored the mechanism of ETH regulation on the growth and secondary metabolites of forage ramie using transcriptomic and metabolomic analyses. Spraying ramie with ETH elevated the contents of flavonoids and chlorogenic acid and decreased the lignin content in the leaves and stems. A total of 1076 differentially expressed genes (DEGs) and 51 differentially expressed metabolites (DEMs) were identified in the leaves, and 344 DEGs and 55 DEMs were identified in the stems. The DEGs that affect phenylpropanoid metabolism, including BGLU41, LCT, PER63, PER42, PER12, PER10, POD, BAHD1, SHT, and At4g26220 were significantly upregulated in the leaves. Ethylene sprays downregulated tyrosine and chlorogenic acid (3-O-caffeoylquinic acid) in the leaves, but lignin biosynthesis HCT genes, including ACT, BAHD1, and SHT, were up- and downregulated. These changes in expression may ultimately reduce lignin biosynthesis. In addition, the upregulation of caffeoyl CoA-O-methyltransferase (CCoAOMT) may have increased the abundance of its flavonoids. Ethylene significantly downregulated metabolites, affecting phenylpropanoid metabolism in the stems. The differential 4CL and HCT metabolites were downregulated, namely, phenylalanine and tyrosine. Additionally, ETH upregulated 2-hydroxycinnamic acid and the cinnamyl hydroxyl derivatives (caffeic acid and p-coumaric acid). Cinnamic acid is a crucial intermediate in the shikimic acid pathway, which serves as a precursor for the biosynthesis of flavonoids and lignin. The ETH-decreased gene expression and metabolite alteration reduced the lignin levels in the stem. Moreover, the HCT downregulation may explain the inhibited lignin biosynthesis to promote flavonoid biosynthesis. In conclusion, external ETH application can effectively reduce lignin contents and increase the secondary metabolites of ramie without affecting its growth and development. These results provide candidate genes for improving ramie and offer theoretical and practical guidance for cultivating ramie for forage.
通讯机构：
[Christian Dubos] I;IPSiM, University Montpellier, CNRS, INRAE, Institut Agro, Montpellier, France<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Iron (Fe) is an essential micronutrient for plant growth and development. Fe availability affects crops' productivity and the quality of their derived products and thus human nutrition. Fe is poorly available for plant use since it is mostly present in soils in the form of insoluble oxides/hydroxides, especially at neutral to alkaline pH. How plants cope with low-Fe conditions and acquire Fe from soil has been investigated for decades. Pioneering work highlighted that plants have evolved two different strategies to mine Fe from soils, the so-called Strategy I (Fe reduction strategy) and Strategy II (Fe chelation strategy). Strategy I is employed by non-grass species whereas graminaceous plants utilize Strategy II. Recently, it has emerged that these two strategies are not fully exclusive and that the mechanism used by plants for Fe uptake is directly shaped by the characteristics of the soil on which they grow (e.g., pH, oxygen concentration). In this review, recent findings on plant Fe uptake and the regulation of this process will be summarized and their impact on our understanding of plant Fe nutrition will be discussed.
通讯机构：
[Zhenxie Yi] C;College of Agronomy, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
通讯机构：
[Cui, GX ; Liu, XY ] H;Hunan Agr Univ, Sch Chem & Mat Sci, Changsha 410128, Peoples R China.;Hunan Agr Univ, Coll Agron, Changsha 410128, Peoples R China.
关键词：
Cannabidiol;Electrochemical sensing;Gold nanoparticles;Carbon black
摘要：
Cannabidiol (CBD), a significant secondary metabolite of Cannabis sativa L., has pharmacological effects for the treatment of a variety of health conditions, including nerve protection, epilepsy, anti-inflammatory, anti-anxiety, and cancer, which have garnered increasing interest in recent years. Herein, an electrochemical sensing platform was constructed for ultrasensitive determination of CBD, on the base of a glassy carbon electrode (GCE) chemically modified with carbon black (CB) and gold nanoparticles (AuNPs) (CB/AuNPs/GCE). The morphology, structure and electrochemical performance of prepared CB/AuNPs/GCE were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Ultraviolet-visible spectroscopy (UV-vis), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical technologies. The effects of pH, scanning rate, enrichment time, enrichment potential and the speculated mechanism of cannabidiol reaction at modified electrode were studied in detail. Under the optimized conditions, the fabricated sensing platform exhibited a great linear response of 0.42 mu A mu M-1 in the concentration range of 0.25 similar to 50.0 mu M. The prepared CB/AuNPs/GCE showed long-term stability, good repeatability and high practicability in real samples of industrial hemp. The proposed sensor can be further enhanced for portable and rapid detection of plant secondary metabolites, providing a basis for food detection, agricultural development, and drug detection.
作者机构：
[Zhou, Yanbiao; Yang, Yuanzhu] Hunan Hybrid Rice Res Ctr, State Key Lab Hybrid Rice, Changsha 410125, Hunan, Peoples R China.;[Zhao, Xinhui; Tang, Qianying; Zhang, Zhihui; Fu, Jun; Liu, Lan; Zhou, Yanbiao; Yang, Runqiu; Yang, Yuanzhu; Tang, Xiaodan] Yuan Longping High Tech Agr Co Ltd, Key Lab Southern Rice Innovat & Improvement, Minist Agr & Rural Affairs, Changsha 410001, Hunan, Peoples R China.;[Zhou, Yanbiao] South China Agr Univ, Coll Life Sci, Guangzhou 510642, Peoples R China.;[Zhang, Zhihui; Yang, Yuanzhu] Huazhong Agr Univ, Coll Plant Sci & Technol, Wuhan 430070, Hubei, Peoples R China.;[Zhao, Xinhui; Yang, Yuanzhu] Hunan Agr Univ, Coll Agron, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Yang, Yuanzhu; Zhou, Yanbiao] S;State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha, 410125, Hunan, China.;Key Laboratory of Southern Rice Innovation and Improvement, Ministry of Agriculture and Rural Affairs, Yuan Longping High-Tech Agriculture Co., Ltd., Changsha, 410001, Hunan, China.;College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.;College of Life Sciences, Hunan Normal University, Changsha, 410081, Hunan, China.
关键词：
STK;Salt stress;Rice;ROS scavenging;ABA
摘要：
BACKGROUND: Soil salinization is a major abiotic environmental stress factor threatening crop production throughout the world. Salt stress drastically affects the growth, development, and grain yield of rice (Oryza sativa L.), and the improvement of rice tolerance to salt stress is a desirable approach for meeting increasing food demand. Receptor-like cytoplasmic kinases (RLCKs) play essential roles in plant growth, development and responses to environmental stresses. However, little is known about their functions in salt stress. Previous reports have demonstrated that overexpression of an RLCK gene SALT TOLERANCE KINASE (STK) enhances salt tolerance in rice, and that STK may regulate the expression of GST (Glutathione S-transferase) genes. RESULTS: The expression of STK was rapidly induced by ABA. STK was highest expressed in the stem at the heading stage. STK was localized at the plasma membrane. Overexpression of STK in rice increased tolerance to salt stress and oxidative stress by increasing ROS scavenging ability and ABA sensitivity. In contrast, CRISPR/Cas9-mediated knockout of STK increased the sensitivity of rice to salt stress and oxidative stress. Transcriptome sequencing analysis suggested that STK increased the expression of GST genes (LOC_Os03g17480, LOC_Os10g38140 and LOC_Os10g38710) under salt stress. Reverse transcription quantitative PCR (RT-qPCR) suggested that four stress-related genes may be regulated by STK including OsABAR1, Os3BGlu6, OSBZ8 and OsSIK1. CONCLUSIONS: These findings suggest that STK plays a positive regulatory role in salt stress tolerance by inducing antioxidant defense and associated with the ABA signaling pathway in rice.
通讯机构：
[Qingyun Yan] E;Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
关键词：
Interdomain interactions;Microbial community;Network complexity;Trophic status
摘要：
The maize LSCgene, encoding a large subunit of ribonucleotide reductase, modulates dNTP synthesis, subsidiary cell development and plant growth. The four-celled stomatal complex consists of a pair of guard cells (GCs) and two subsidiary cells (SCs) in grasses, which supports a fast adjustment of stomatal aperture. The formation and development of SCs are thus important for stomatal functionality. Here, we report a maize lost subsidiary cells (lsc) mutant, with many stomata lacking one or two SCs. The loss of SCs is supposed to have resulted from impeded subsidiary mother cell (SMC) polarization and asymmetrical division. Besides the defect in SCs, the lsc mutant also displays a dwarf morphology and pale and striped newly-grown leaves. LSC encodes a large subunit of ribonucleotide reductase (RNR), an enzyme involved in deoxyribonucleotides (dNTPs) synthesis. Consistently, the concentration of dNTPs and expression of genes involved in DNA replication, cell cycle progression, and SC development were significantly reduced in the lsc mutant compared with the wild-type B73 inbred line. Conversely, overexpression of maize LSC increased dNTP synthesis and promoted plant growth in both maize and Arabidopsis. Our data indicate that LSC regulates dNTP production and is required for SMC polarization, SC differentiation, and growth of maize.
摘要：
The objective was to determine effects of cellulase, xylanase, and commercial fibrolytic enzymes on fermentation quality, aerobic stability, bacterial community, and in vitro degradation of mixed silages. Mixtures of alfalfa, wheat bran, and rice straw [80:15:5 on a fresh matter (FM) basis] were ensiled for 1, 3, 5, 7, 15, 30, and 45 d after treatment with: distilled water (control, C); cellulase (E); xylanase (X); or commercial fibrolytic enzymes (EX), with all enzyme preparations applied at 100 U/g FM. The 45-day silages were subjected to an in vitro degradation test. Each of the three enzyme-treated groups enriched relative abundance (RA) of Lactobacillus, Weissella, and Stenotrophomonas maltophilia, increased water soluble carbohydrate (WSC) concentrations, and extended aerobic stability over 384 h, but concurrently inhibited growth of undesirable microbes (i.e., Acinetobacter sp, Lelliottia amnigena, and Sphingomonas sp), reducing pH and concentrations of ammonia nitrogen (AN), butyric acid (BA) and propionic acid (PA). Compared to C, adding X or EX increased the RA of L. paralimentarius and L. parabrevis, enhanced accumulation of acetic acid (AA) and crude protein (CP), and reduced hemicellulose content. Furthermore, E group silage had the highest abundance of W. cibaria. In addition, EX enriched RA of Bacillus velezensis, reduced AN concentration, increased DM degradability, total VFA production, and gas production during in vitro incubation. In conclusion, addition of X or EX enhanced ensiling by enhancing concentrations of AA; however, EX was the most promising enzyme, based on reducing AN concentration and increasing DM content and DM degradability.
