一种畅销的天然药用植物——缬草

缬草(Valeriana officinalis L.)是败酱科缬草属多年生高大草本植物,又名小救贺、大救贺、五里香、满坡香等,根、茎供药用。该属植物在全世界有250余种,主要生长在气候温和、湿度较大的山坡草地、林下和沟边等地区。随着人类生活节奏的加快,生活压力也随之增加,像失眠、抑郁、肿瘤等疾病更加频繁地出现,影响了人类的健康状况和生活水平。我们生活中常见的很多化学合成类药物在治疗疾病方面虽然效果明显,但是副作用往往很大。缬草作为天然资源植物,具有镇静安神、解痉止痛的功效,在临床中可以用来缓解心神不安、心悸、失眠、焦虑、胃肠道疼痛等症状。另外

磷钨酸和干燥处理提高植物样品显微CT成像对比度的方法

显微CT技术是一种非破坏性的三维成像技术,在医学、地质学、材料学等方面有着广泛的应用,在植物成像方面也是一种前景很好的技术手段。但植物组织主要由轻元素构成,X射线成像对比度很低,其应用受到很大限制。本文在前人的研究基础上,使用不同浓度的磷钨酸处理不同植物样品,比较不同处理时间、不同植物结构的差异,经CO_2临界点干燥后再扫描等前处理方法对显微CT成像效果的影响,探索出增强植物材料成像对比度的处理流程,使其更适用于显微CT扫描

羊草LcCBF6基因的表达特性和功能研究

羊草是我国重要的牧草和生态草资源,具有耐盐碱、耐旱、耐低温等特性,是天然的抗逆基因资源库。CBF/DREB属于AP2转录因子家族,在植物抗逆中发挥着重要作用。本研究克隆得到羊草LcCBF6(Leymus chinensis Crepeat binding factor 6)基因,该基因含有AP2结构域,编码245个氨基酸。氨基酸序列比对发现,LcCBF6与蒙古冰草和黑麦的CBF6蛋白的同源性分别为92%和91%。组织特异性表达模式分析表明,LcCBF6基因在羊草根、叶、种子中均有表达,且受盐胁迫诱导表达。过表达LcCBF6能显著提高转基因拟南芥的抗盐性。在盐胁迫条件下,转基因株系的绿色子叶数、根长、植株生物量以及存活率等均明显高于野生型。上述结果表明羊草LcCBF6基因在提高植物盐胁迫抗性方面发挥了重要的作用,将为牧草及重要农作物抗逆分子育种提供优异的基因资源

镉低积累水稻品种选育研究进展

水稻(Oryza sativa L.)是我国主要粮食作物之一,稻米镉超标问题严重威胁人体健康。降低稻米镉污染风险,实现水稻安全生产迫在眉睫。镉低积累水稻品种选育是降低稻米镉污染风险经济有效的方法之一。从常规表型筛选到分子标记辅助筛选,从常规育种到分子标记辅助育种、基因工程育种、基因编辑和分子设计育种等分子育种技术,低镉水稻品种选育技术将会走向精准化、高效化与智能化,为水稻的安全生产提供了巨大推动力。综述了镉低积累水稻品种筛选与低镉水稻材料创制的研究进展,并对未来低镉水稻新一代分子育种技术的发展方向进行展望,旨在为保障我国粮食安全与居民健康提供科学支撑

中国外来归化植物的编目现状及有关问题

在简要讨论外来植物相关定义的基础上,对中国外来归化植物的调查和编目现状进行了概述;并对近年发表的两篇文章中外来归化植物数据进行了订正

The Development and Evaluation of a Backpack LiDAR System for Accurate and Efficient Forest Inventory

Forest inventory holds an essential role in forest management and research, but the existing field inventory methods are highly time-consuming and labor-intensive. Here, we developed a simultaneous localization and mapping-based backpack light detection and ranging (LiDAR) system with dual orthogonal laser scanners and an open-source Python package called Forest3D for efficient and accurate forest inventory applications. Two key forest inventory variables, tree height and diameter at breast height (DBH), were extracted at six study sites with different tree species compositions. In addition, the vertical point density distribution and leaf area density (LAD) were calculated for two complex natural forest sites. The results showed that the backpack LiDAR system together with the Forest3D package accurately estimated the tree height (R-2 = 0.65, RMSE = 1.90 m) and DBH (R-2 = 0.95, RMSE = 0.02 m), which were equivalent to those derived from terrestrial laser scanning (TLS), but with much higher efficiency. The point density of the backpack LiDAR data was higher than or the same as that of the TLS data across all height strata, and the estimated LAD fit well with the TLS estimates (R-2 > 0.92, RMSE = 0.01 m(2)/m(3)). The backpack LiDAR system, along with the Forest3D package, provides an efficient and accurate solution for extracting forest inventory variables, which should be of great interests to forest managers and researchers

Structural basis of bilin binding by the chlorophyll biosynthesis regulator GUN4

The chlorophyll biosynthesis regulator GENOMES UNCOUPLED 4 (GUN4) is conserved in nearly all oxygenic photosynthetic organisms. Recently, GUN4 has been found to be able to bind the linear tetrapyrroles (bilins) and stimulate the magnesium chelatase activity in the unicellular green alga Chlamydomonas reinhardtii. Here, we characterize GUN4 proteins from Arabidopsis thaliana and the cyanobacterium Synechocystis sp. PCC 6803 for their ability to bind bilins, and present the crystal structures of Synechocystis GUN4 in biliverdin-bound, phycocyanobilin-bound, and phytochromobilin-bound forms at the resolutions of 1.05, 1.10, and 1.70 angstrom, respectively. These linear molecules adopt a cyclic-helical conformation, and bind more tightly than planar porphyrins to the tetrapyrrole-binding pocket of GUN4. Based on structural comparison, we propose a working model of GUN4 in regulation of tetrapyrrole biosynthetic pathway, and address the role of the bilin-bound GUN4 in retrograde signaling

GmPIN-dependent polar auxin transport is involved in soybean nodule development

To overcome nitrogen deficiency, legume roots establish symbiotic interactions with nitrogen-fixing rhizobia that are fostered in specialized organs (nodules). Similar to other organs, nodule formation is determined by a local maximum of the phytohormone auxin at the primordium site. However, how auxin regulates nodule development remains poorly understood. Here, we found that in soybean, (Glycine max), dynamic auxin transport driven by PIN-FORMED (PIN) transporter GmPIN1 is involved in nodule primordium formation. GmPIN1 was specifically expressed in nodule primordium cells and GmPIN1 was polarly localized in these cells. Two nodulation regulators, (iso)flavonoids trigger expanded distribution of GmPIN1b to root cortical cells, and cytokinin rearranges GmPIN1b polarity. Gmpin1abc triple mutants generated with CRISPR-Cas9 showed the impaired establishment of auxin maxima in nodule meristems and aberrant divisions in the nodule primordium cells. Moreover, overexpression of GmPIN1 suppressed nodule primordium initiation. GmPIN9d, an ortholog of Arabidopsis thaliana PIN2, acts together with GmPIN1 later in nodule development to acropetally transport auxin in vascular bundles, fine-tuning the auxin supply for nodule enlargement. Our findings reveal how PIN-dependent auxin transport modulates different aspects of soybean nodule development and suggest that the establishment of auxin gradient is a prerequisite for the proper interaction between legumes and rhizobia

Changes in above-/below-ground biodiversity and plant functional composition mediate soil respiration response to nitrogen input

1. Biodiversity loss and changes in plant community composition induced by anthropogenic nitrogen (N) deposition exert profound effects on ecosystem functions. However, limited studies have considered the joint effects of plant community composition, plant species richness, plant functional diversity and soil biodiversity on the dynamics of soil autotrophic and heterotrophic respiration under extra N input. 2. We addressed this issue by conducting a multilevel N-manipulation experiment in a Tibetan alpine steppe. Based on soil respiration observations as well as biotic and abiotic measurements under this N addition experiment, we quantified the relative and interactive effects of above-/below-ground biodiversity, plant community composition and other explanatory variables (environmental factors, plant and microbial properties) on autotrophic and heterotrophic respiration. 3. Our results showed that the effects of N enrichment via plant productivity, root amount, the proportion of sedge biomass and plant functional diversity explained 71% of the N-induced variations in autotrophic respiration. With regard to heterotrophic respiration, the combination of N addition, soil pH, plant functional diversity and soil biota diversity accounted for 78% of its variations along the N addition gradient. Further analyses showed that above-/below-ground diversity loss and changes in plant community composition explained similar variation to that contributed by other factors in both autotrophic and heterotrophic respiration. The declined plant functional diversity and the increased proportion of sedge biomass promoted autotrophic respiration. Conversely, the loss of soil biodiversity together with the decreased plant functional diversity led to the decline of heterotrophic respiration along the experimental N gradient. 4. Our results highlight that the indirect regulation of N input on ecosystem function through changes in plant community composition and above-/below-ground biodiversity loss should be considered for better understanding the responses of terrestrial ecosystems to atmospheric N deposition

Capturing single-copy nuclear genes, organellar genomes, and nuclear ribosomal DNA from deep genome skimming data for plant phylogenetics: A case study in Vitaceae

With the decreasing cost and availability of many newly developed bioinformatics pipelines, next-generation sequencing (NGS) has revolutionized plant systematics in recent years. Genome skimming has been widely used to obtain high-copy fractions of the genomes, including plastomes, mitochondrial DNA (mtDNA), and nuclear ribosomal DNA (nrDNA). In this study, through simulations, we evaluated the optimal (minimum) sequencing depth and performance for recovering single-copy nuclear genes (SCNs) from genome skimming data, by subsampling genome resequencing data and generating 10 data sets with different sequencing coverage in silico. We tested the performance of four data sets (plastome, nrDNA, mtDNA, and SCNs) obtained from genome skimming based on phylogenetic analyses of the Vitis clade at the genus level and Vitaceae at the family level, respectively. Our results showed that optimal minimum sequencing depth for high-quality SCNs assembly via genome skimming was about 10x coverage. Without the steps of synthesizing baits and enrichment experiments, coupled with incredibly low sequencing costs, we showcase that deep genome skimming (DGS) is as effective for capturing large data sets of SCNs as the widely used Hyb-Seq approach, in addition to capturing plastomes, mtDNA, and entire nrDNA repeats. DGS may serve as an efficient and economical alternative and may be superior to the popular target enrichment/Hyb-Seq approach