分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert (the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone (SS1) distributes all the 126 endemic species, Arabian regional subzone (SS2) owns 79 taxa, and Nubo-Sindian subzone (SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis (TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., I Asphodelus refractus group, II Agathophora alopecuroides var. papillosa group, III Anvillea garcinii group, IV Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, VI Scrophularia deserti group, and VII Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region.
分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： The presence of invasive plant species poses a substantial ecological impact, thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary. This study uses maximum entropy (MaxEnt) modeling to forecast the likelihood of Leucaena leucocephala (Lam.) de Wit invasion in Saudi Arabia under present and future climate change scenarios. Utilizing the MaxEnt modeling, we integrated climatic and soil data to predict habitat suitability for the invasive species. We conducted a detailed analysis of the distribution patterns of the species, using climate variables and ecological factors. We focused on the important influence of temperature seasonality, temperature annual range, and precipitation seasonality. The distribution modeling used robust measures of area under the curve (AUC) and receiver-operator characteristic (ROC) curves, to map the invasion extent, which has a high level of accuracy in identifying appropriate habitats. The complex interaction that influenced the invasion of L. leucocephala was highlighted by the environmental parameters using Jackknife test. Presently, the actual geographic area where L. leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range, suggesting that it had the capacity to expand further. The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve. Precipitation and temperature were the primary factors influencing the potential distribution of L. leucocephala. Currently, an estimated area of 216,342 km2 in Saudi Arabia was at a high probability of invasion by L. leucocephala. We investigated the potential for increased invasion hazards in the future due to climate change scenarios (Shared Socioeconomic Pathways (SSPs) 245 and 585). The analysis of key climatic variables, including temperature seasonality and annual range, along with soil properties such as clay composition and nitrogen content, unveiled their substantial influence on the distribution dynamic of L. leucocephala. Our findings indicated a significant expansion of high risk zones. High-risk zones for L. leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios, particularly evident in southern Makkah, Al Bahah, Madina, and Asir areas. The results, backed by thorough spatial studies, emphasize the need to reduce the possible ecological impacts of climate change on the spread of L. leucocephala. Moreover, the study provides valuable strategic insights for the management of invasion, highlighting the intricate relationship between climate change, habitat appropriateness, and the risks associated with invasive species. Proactive techniques are suggested to avoid and manage the spread of L. leucocephala, considering its high potential for future spread. This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge. It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions.
分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Rising atmospheric CO2 (carbon dioxide) concentrations and salinization are manifestations of climate change that affect plant growth and productivity.Species with an intermediate C3-C4 type of photosynthesis live in a wide range of precipitation, temperature, and soil quality, but are more often found in warm and dry habitats. One of the intermediate C3-C4 photosynthetic type is C2 photosynthesis with a carbon concentration mechanism (CCM) that reassimilates CO2 released via photorespiration. However, the ecological significance under which C2 photosynthesis has advantages over C3 and C4 plants remains largely unexplored. Salt tolerance and functioning of CCM were studied in plants from two populations (P1 and P2) of Sedobassia sedoides (Pall.) Freitag G. Kadereit Asch. species with C2 photosynthesis exposed to 4 d and 10 d salinity (200 mM NaCl) at ambient (785.7 mg/m3, aCO2) and elevated (1571.4 mg/m3, eCO2) CO2. On the fourth day of salinity, an increase in Na+ content, activity catalase, and superoxide dismutase was observed in both populations. P2 plants showed an increase in proline content and a decrease in photosynthetic enzyme content: rubisco, phosphoenolpyruvate carboxylase (PEPC), and glycine decarboxylase (GDC), which indicated a weakening of C2 and C4 characteristics under salinity. Treatment under 10 d salinity led to an increased Na+ content and activity of cyclic electron flow around photosystem I (PSI CEF), a decreased content of K+ and GDC in both populations. P1 plants showed greater salt tolerance, which was assessed by the degree of reduction in photosynthetic enzyme content, PSI CEF activity, and changes in relative growth rate (RGR). Differences between populations were evident under the combination of eCO2 and salinity. Under long-term salinity and eCO2, more salt-tolerant P1 plants had a higher dry biomass (DW), which was positively correlated with PSI CEF activity. In less salt-tolerant P2 plants, DW correlated with transpiration and dark respiration. Thus, S. sedoidesshowed a high degree of photosynthetic plasticity under the influence of salinity and eCO2 through strengthening (P1 plants) and weakening C4characteristics (P2 plants).
分类： 生物学 >> 微生物学 分类： 生物学 >> 植物学 提交时间： 2024-07-10
摘要： Plants evolved sophisticated genetic and metabolic mechanisms to shape their “core microbiome” under normal growth conditions. However, whether natural plant ecotypes re-shape a core “stress responsive microbiome” remains elusive. Considering that drought is the most serious abiotic stress worldwide, we conducted comparative microbiome analysis to study the potential conserved core root microbiome changes upon drought stress in natural Arabidopsis ecotypes. We screened the drought tolerance of 130 worldwide Arabidopsis ecotypes, and chose the extremely drought tolerant and sensitive ecotypes for comparative microbiome studies. We detected diverse differentially abundant ASVs , network driver taxa, as well as key functions pathways shared in diverse ecotypes upon drought stress, indicating the existence of some core drought-responsive microbiome changes. Our work unveiled the existence of a core drought-responsive microbiome and its critical role in enhancing plant fitness. This work also provided a research paradigm for guiding the discovery of stress-alleviating microbiomes in sustainable agriculture using natural ecotypes.
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 为探讨山药腐烂块茎的真菌群落特征及主要病原，该研究采用ITS 扩增子测序技术 和FUNGuild 分析阐明了其真菌群落组成、网络特征及生态功能类群，并对潜在病原真菌 进行了分离鉴定。结果表明： （ 1 ） 山药腐烂块茎中的优势菌门为子囊菌门 （Ascomycota），优势属包括青霉属（Penicillium）、炭疽菌属（Colletotrichum）、镰刀 菌属（Fusarium）、篮状菌属（Talaromyces）和粉红螺旋聚孢霉属（Clonostachys）等。 真菌生态网络呈现明显的模块化和高比例的正相关边数（99.33%），真菌间趋向于极强的 正向合作。（2）FUNGuild 分析显示，10 个真菌生态功能类群与山药块茎腐烂高度相关。 其中， 凋落物腐生- 未命名腐生- 木腐菌（ dung saprotroph-undefined saprotroph-wood saprotroph）和内生-植物病原真菌（endophyte-plant pathogen）的相对丰度分别达到33.74% 和23.64%，其代表性属分别为青霉和炭疽属。除此之外，与植物病原和木腐菌同时相关的 生态功能类群共有3 个，总相对丰度达到13.67%，代表性属为镰刀菌属。进一步Trait 分 析表明，青霉和镰刀菌等7 属真菌很可能与山药块茎腐烂密切相关。（3）共分离鉴定真菌 22 株，隶属于6 个属，包括镰刀菌属（9 株）、青霉属（5 株）和曲霉属（Aspergillus，4 株）等。该研究结果为阐明山药块茎腐烂的发病规律、定向使用农药及筛选生防菌提供了 很好的参考。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 报道中国柿科（Ebenaceae）柿属植物二新记录种——粗毛叶柿（Diospyros dasyphylla Kurz）和苏门答腊柿（Diospyros sumatrana Miq.），提供了二新记录种的形态特征、物候期、 生境特点和分布等信息，并基于国内的野外调查情况对其进行了濒危等级评估。粗毛叶柿与 木果柿（Diospyros xylocarpa Y. M. Shui, W. H. Chen Sima）相似，区别在于前者的幼枝及 叶背密被黄褐色糙毛，成熟果直径约6 cm，宿存果萼长8 mm；苏门答腊柿与椭圆叶柿 （Diospyros elliptifolia Merr.）相似，区别在于其前者的花冠白色，瓶状，果直径约2 cm， 宿存果萼直立。凭证标本存放于广西植物研究所标本馆（IBK）和北京林业大学博物馆（BJFC）。 这些资料为中国柿属植物多样性研究提供了基础数据。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 以花叶类玉兰的全绿叶、花叶和全黄叶为试验材料，该研究从叶片光合色素含量、叶 片解剖结构、光响应曲线等方面探讨3 种类型叶片的解剖结构与光合特性的关系，从解剖学 揭示花叶类玉兰光合特性成因。结果表明：（1）花叶类玉兰的黄色叶斑是由叶绿体结构异常 导致叶绿素含量降低形成的叶绿素型叶斑。（2）花叶类玉兰黄色区域类囊体结构异常，ATP 合成受阻，阻碍了光合作用的正常进行。（3）解剖结构显示全绿叶栅栏组织发达，叶绿体完 整性和色素含量均高于花叶和全黄叶，其净光合速率较高。（4）全绿叶和花叶的最大净光合 速率和光饱和点存在显著性差异，全绿叶较花叶能够耐受更大范围的强光。该研究进一步阐 明了花叶类玉兰的叶绿体结构影响其光合特性，为花叶类玉兰的优良种质选育提供了参考。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 为揭示赤皮青冈叶色黄化变异机制，该研究以赤皮青冈叶色变异植株和正常植株的 叶片为试验材料，采用超高效液相色谱串联质谱法和高通量RNA 测序技术分别进行代谢组 和转录组分析。结果表明：（1）代谢组在正、负离子模式下分别检测出正常植株和突变体 之间存在257 个和357 个显著差异代谢物（significantly changed metabolites，SCMs），其中 槲皮素、白矢车菊素、杨梅素等多种黄酮类化合物及其糖苷衍生物（吡喃酮啡肽A、异鼠李 素3-葡糖苷酸等）在突变体中显著上调，而叶绿素a、叶绿素b、类胡萝卜素等色素含量则 显著下降。（2）转录组测序检测出4 146 个差异表达基因（differentially expressed genes， DEGs），其中1 711 个基因上调表达，2 435 个基因下调表达。（3）KEGG 富集分析表明， SCMs 和DEGs 显著富集到光合作用、卟啉与叶绿素代谢、类黄酮生物合成等途径。研究结 果表明突变体叶色黄化可能是受到叶绿素合成受阻、叶绿体发育异常以及黄酮物质合成增加 等因素的综合作用。此外，MYB 和bHLH 家族基因在突变体中显著上调，证实该两类转录 因子参与调控类黄酮生物合成。该研究结果为植物黄化突变的分子机制提供了新的见解，也 为叶色功能基因挖掘与园林植物育种工作提供了参考。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 叶际微生物种群稳定与烟株健康密切相关。为揭示感染野火病烟株叶际微生态特征，该 文采用Illumina 高通量测序技术对不同发病程度烟株叶片的病斑与健康组织进行微生物群落结 构与多样性分析。结果显示：（1）病斑组织与健康组织优势菌为变形菌门（Proteobacteria）和 子囊菌门（Ascomycota），且在病斑组织的相对丰度显著高于健康组织；优势属为假单胞菌属 （Pseudomonas）、泛菌属（Pantoea）、链格孢属（Alternaria）、小不整球壳属（Plectosphaerella） 和锥盖伞属（Conocybe），仅假单胞菌属在病斑组织的相对丰度显著高于健康组织。（2）病斑组 织细菌群落多样性和丰富度高于健康组织，并随病害程度的增加，多样性指数呈先减后增、丰 富度指数呈先增后减趋势；病斑组织真菌群落丰富度和多样性指数随病害程度的增加先增后减， 轻度和中度病叶病斑组织真菌群落多样性和丰富度高于健康组织，但重病组织真菌群落多样性 和丰富度低于健康组织。（3）病斑和健康组织细菌的基因功能信息及相对丰度基本类似，主要 为代谢、遗传信息处理和环境信息处理3 类；真菌的优势功能类群为植物病原菌、动物病原菌- 内生真菌-植物病原菌-木质腐生真菌、未定义腐生真菌、木质腐生真菌和植物病原菌-木质腐生 真菌。该结果为认识烟草野火病演变规律及叶际微生物群落特征提供了科学依据。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 青枯病是番茄(Solanum lycopersicum)生产中的一种毁灭性土传病害，致病菌生理小 种复杂、易变异，而MLO 基因隐性突变mlo 具有广谱抗性，前期研究表明Slmlo1/6 可能参 与番茄青枯病抗性反应。为进一步研究番茄Slmlo1/6 青枯病抗性基因功能，该文利用 CRISPR/Cas9 技术创制Slmlo1/6 基因突变材料，并进行表型鉴定。结果表明：（1）首先设 计SlMLO1/6 靶点序列gRNA，并与U6 启动子组装，再将含高效靶点的U6-gRNA1/6 片段 通过Bsa I 酶切连入CRISPR 载体pBGK，构建形成双基因融合敲除载体pBGK-SlMLO1/6。 重组质粒经转化大肠杆菌(Escherichia coli)感受态DH5α和平板培养，挑选阳性单克隆。验证 正确后，再经农杆菌(Agobacterium tumefaciens) GV3101 介导的遗传转化和潮霉素抗性筛选， 最终获得9 株番茄编辑苗。（2） 靶点区测序显示，植株M2 和M8 分别缺失177 bp 和7 bp 的SlMLO1 片段，M7 缺失12 bp 的SlMLO6 片段，M9 发生SlMLO6 单碱基T 插入，总计4 株单基因纯合突变体，其他均为杂合型突变。（3）RT-qPCR 分析表明，与野生型相比，突 变株SlMLO1/6 基因表达水平显著下降，尤其是M2、M7 和M8。（4）表型鉴定表明，SlMLO1/6 可能是番茄青枯病易感基因。总之，该文成功构建了MLO 基因编辑载体并实现了番茄转化， 纯合突变体获得了青枯病抗性。氨基酸丢失和移码突变可能是Slmlo1/6 抗性功能转变的主 要原因。该研究结果为番茄抗青枯病基因功能研究和抗病育种应用提供了理论基础和遗传工 程材料。
分类： 生物学 >> 植物学 提交时间： 2024-06-02 合作期刊: 《广西植物》
摘要： 野生植物在人们的日常生活中发挥着举足轻重的作用，提供了诸多生计必需品。札达 县，位于中国西藏自治区阿里地区（མངའ་རི, 转写：mngav-ri）的西南部，与印度相邻，是通往 南亚的重要通道。该地属于高原亚寒带干旱气候区，藏族人群在适应恶劣的环境中掌握了丰 富的野生植物利用的传统知识。为全面系统地调查、记录和研究札达县藏族对野生植物的传 统利用知识，该研究采用了民族植物学的调查研究方法，共访谈到173 位信息报告人，记录 3 639 条利用报告（UR）。通过UV、CV 和CII 等定量分析方法，得出了以下结果：（1） 札达县藏族掌握着丰富的野生植物利用传统知识，利用119 种野生植物，分属40 科83 属。 （2）该地野生植物利用类别多样，有8 个利用类别，且多种植物同时具有两种及以上用途。 （3）人们生活中最重要的植物是葛缕子（Carum carvi）（UV=1.220）、冻原白蒿（Artemisia stracheyi）（UV=0.919）、心叶大黄（Rheum acuminatum）（UV=0.890）、柏木（Cupressus sp.）（UV=0.769）和异株荨麻（Urtica dioica）（UV=0.757），这些植物和当地藏族生活息 息相关。（4）复杂多样的高原环境显著影响该地区野生植物的利用。该研究不仅系统地记录 了札达县野生植物的利用知识和特征，有助于该地区植物资源的深入挖掘与利用，促进传统 知识的传承，并对生物多样性的保护具有积极意义。
分类： 生物学 >> 植物学 提交时间： 2024-05-15 合作期刊: 《干旱区科学》
摘要： Phyllosphere microorganisms are a crucial component of environmental microorganisms, highly influenced by host characteristics, and play a significant role in plant health and productivity. Nonetheless, the impact of host characteristics on shaping phyllosphere microbial communities of plants with different life forms remains ambiguous. Utilizing high-throughput sequencing technology, this study analyzed the diversity and community composition of phyllosphere epiphytic microorganisms (e.g., bacteria and fungi) of various plant life forms in the hinterland of the Gurbantunggut Desert, Northwest China. Functional annotation of prokaryotic taxa (FAPROTAX) and fungi function guild (FUNGuild) were employed to assess the ecological functions of microorganisms and to investigate the role of stochastic and deterministic processes in shaping phyllosphere microbial communities. Result showed a diverse array of phyllosphere epiphytic microorganisms in the desert plants, with Proteobacteria, Cyanobacteria, and Actinobacteriota dominating bacterial community, while Ascomycota and Basidiomycota were prevalent in fungal community. Comparison across different plant life forms highlighted distinct microbial communities, indicating strong filtering effects by plant characteristics. FAPROTAX prediction identified intracellular parasites (accounting for 27.44% of bacterial community abundance), chemoheterotrophy (10.12%), and phototrophy (17.41%) as the main functions of epiphytic bacteria on leaves of different life form plants. FUNGuild prediction indicated that phyllosphere epiphytic fungi primarily served as Saprotrophs (81.77%), Pathotrophs (17.41%), and Symbiotrophs (0.82%). Co-occurrence network analysis demonstrated a predominance of positive correlations among different microbial taxa. Raup-Crick dissimilarity index analysis revealed that deterministic processes predominantly influenced phyllosphere bacterial and fungal community assembly. Variance partitioning analysis and random forest modeling suggested that plant leaf functional traits significantly impacted both bacterial and fungal community composition, with fungal community composition showing a closer association with leaf nutrients and physiology compared with bacterial community composition. The distinct responses of bacterial and fungal communities to plant traits were attributed to the differing properties of bacteria and fungi, such as bacteria having higher potential dispersal rates and broader ecological niches than fungi. Overall, the results indicate that phyllosphere bacterial and fungal communities undergo similar community assembly processes, with fungi being more influenced by plant characteristics than bacteria. These findings offer novel insights into the ecology of phyllosphere microbial communities of desert plants.
分类： 生物学 >> 植物学 提交时间： 2024-04-15 合作期刊: 《干旱区科学》
摘要： Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas. However, the self-succession ability of native plants during the later periods of vegetation restoration remains unclear. Therefore, this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions. The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom. forest in the Tengger Desert, China. The germination tests were conducted in a laboratory setting. The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation (60, 40, and 20 a) on the progress of vegetation restoration and ecological conditions in artificial C. korshinskii forest. The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz., Eragrostis minor Host., and Agropyron mongolicum Keng., and the top three dominant plant species in soil seed bank were E. minor, Chloris virgata Sw., and E. gmelinii. As restoration period increased, the density of seed rain and soil seed bank increased first and then decreased. While for species richness, as restoration period increased, it gradually increased in seed rain but decreased in soil seed bank. There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods. The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period. The shape of the seeds, specifically those with external appendages such as spines and crown hair, clearly had an effect on their dispersal, then resulting in lower seed density in soil seed bank. In addition, precipitation was a crucial factor in promoting rapid germination, also resulting in lower seed density in soil seed bank. Our findings provide valuable insights for guiding future interventions during the later periods of artificial C. korshinskii forest, such as sowing and restoration efforts using unmanned aerial vehicles.
分类： 生物学 >> 植物学 提交时间： 2024-04-15 合作期刊: 《干旱区科学》
摘要： The maintenance of sand-fixing vegetation is important for the stability of artificial sand-fixing systems in which seed dispersal plays a key role. Based on field wind tunnel experiments using 11 common plant species on the southeastern edge of the Tengger Desert, China, we studied the secondary seed dispersal in the fixed and semi-fixed sand dunes as well as in the mobile dunes in order to understand the limitations of vegetation regeneration and the maintenance of its stability. Our results indicated that there were significant variations among the selected 11 plant species in the threshold of wind speed (TWS). The TWS of Caragana korshinskii was the highest among the 11 plant species, whereas that of Echinops gmelinii was the lowest. Seed morphological traits and underlying surface could generally explain the TWS. During the secondary seed dispersal processes, the proportions of seeds that did not disperse (no dispersal) and only dispersed over short distance (short-distance dispersal within the wind tunnel test section) were significantly higher than those of seeds that were buried (including lost seeds) and dispersed over long distance (long-distance dispersal beyond the wind tunnel test section). Compared with other habitats, the mobile dunes were the most difficult places for secondary seed dispersal. Buried seeds were the easiest to be found in the semi-fixed sand dunes, whereas fixed sand dunes were the best sites for seeds that dispersed over long distance. The results of linear mixed models showed that after controlling the dispersal distance, smaller and rounder seeds dispersed farther. Shape index and wind speed were the two significant influencing factors on the burial of seeds. The explanatory power of wind speed, underlying surface, and seed morphological traits on the seeds that did not disperse and dispersed over short distance was far greater than that on the seeds that were buried and dispersed over long distance, implying that the processes and mechanisms of burial and long-distance dispersal are more complex. In summary, most seeds in the study area either did not move, were buried, or dispersed over short distance, promoting local vegetation regeneration.
分类： 生物学 >> 植物学 提交时间： 2024-01-12 合作期刊: 《干旱区科学》
摘要： Wolfberry (Lycium barbarum L.) is important for health care and ecological protection. However, it faces problems of low productivity and resource utilization during planting. Exploring reasonable models for water and nitrogen management is important for solving these problems. Based on field trials in 2021 and 2022, this study analyzed the effects of controlling soil water and nitrogen application levels on wolfberry height, stem diameter, crown width, yield, and water (WUE) and nitrogen use efficiency (NUE). The upper and lower limits of soil water were controlled by the percentage of soil water content to field water capacity (f), and four water levels, i.e., adequate irrigation (W0, 75%85% f), mild water deficit (W1, 65%75% f), moderate water deficit (W2, 55%65% f), and severe water deficit (W3, 45%55% f) were used, and three nitrogen application levels, i.e., no nitrogen (N0, 0 kg/hm2), low nitrogen (N1, 150 kg/hm2), medium nitrogen (N2, 300 kg/hm2), and high nitrogen (N3, 450 kg/hm2) were implied. The results showed that irrigation and nitrogen application significantly affected plant height, stem diameter, and crown width of wolfberry at different growth stages (P<0.01), and their maximum values were observed in W1N2, W0N2, and W1N3 treatments. Dry weight per plant and yield of wolfberry first increased and then decreased with increasing nitrogen application under the same water treatment. Dry weight per hundred grains and dry weight percentage increased with increasing nitrogen application under W0 treatment. However, under other water treatments, the values first increased and then decreased with increasing nitrogen application. Yield and its component of wolfberry first increased and then decreased as water deficit increased under the same nitrogen treatment. Irrigation water use efficiency (IWUE, 8.46 kg/(hm2mm)), WUE (6.83 kg/(hm2mm)), partial factor productivity of nitrogen (PFPN, 2.56 kg/kg), and NUE (14.29 kg/kg) reached their highest values in W2N2, W1N2, W1N2, and W1N1 treatments. Results of principal component analysis (PCA) showed that yield, WUE, and NUE were better in W1N2 treatment, making it a suitable water and nitrogen management mode for the irrigation area of the Yellow River in the Gansu Province, China and similar planting areas.
分类： 生物学 >> 植物学 分类： 生物学 >> 微生物学 提交时间： 2023-11-17
摘要： Drought is one of the most serious abiotic stresses which also shifts the composition of root associated microbiomes. However, there is a lack of genetic evidence regarding whether and how plant genetic effects positively reshape drought induced microbiome changes. Root hairs play essential roles in water uptaking, but whether root hairs also orchestrate microbiome re-shaping process during drought stress is unknown. By utilizing genetic mutants with enhanced or decreased root hair densities, we detected a significant effect of plant genetic effect on drought induced microbiome changes. In addition, the hairy mutant (gl2) triggers a deterministic process during drought induced microbiome re-assembly, which further confirms the involvement of host effects in re-shaping drought induced microbiome changes. Rhizobiaceae strains were detected as key biomarker species positively correlated with root hair densities. Moreover, the gl2 mutant also shapes more complex microbiome co-occurrence networks, with more Rhizobiaceae hubs. Our findings unveil the novel roles of root hairs in shaping microbiome structure and network interactions upon drought stress, particularly through regulating the abundance and network centrality of Rhizobiaceae strains. Root hair related mutants also broadly affect root metabolome upon drought stress. Understanding the physiological and microbial ecological basis of host mediated microbiome re-shaping under drought helps develop microbiome engineering approaches to combat climate changes.
分类： 生物学 >> 植物学 提交时间： 2023-11-13 合作期刊: 《干旱区科学》
摘要： Endophytes, as crucial components of plant microbial communities, significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts, promote plant growth, and degrade pathogenic fungal mycelia. In this study, an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species, Thymus altaicus and Salvia deserta, using a series of screening media. Plant samples of Thymus altaicus and Salvia deserta were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region, China, in July 2021. Additionally, the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi (Fusarium oxysporum, Fulvia fulva, Alternaria solani, and Valsa mali) were determined through the plate confrontation method. A total of 80 endophytic bacterial strains were isolated from Thymus altaicus, while a total of 60 endophytic bacterial strains were isolated from Salvia deserta. The endophytic bacterial strains from both Thymus altaicus and Salvia deserta exhibited plant growth-promoting properties. Specifically, the strains of Bacillus sp. TR002, Bacillus sp. TR005, Microbacterium sp. TSB5, and Rhodococcus sp. TR013 demonstrated strong cellulase-producing activity, siderophore-producing activity, phosphate solubilization activity, and nitrogen-fixing activity, respectively. Out of 140 endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta, 104 strains displayed anti-fungal activity against Fulvia fulva, Alternaria solani, Fusarium oxysporum, and Valsa mali. Furthermore, the strains of Bacillus sp. TR005, Bacillus sp. TS003, and Bacillus sp. TSB7 exhibited robust inhibition rates against all the four pathogenic fungi. In conclusion, the endophytic bacterial strains from Thymus altaicus and Salvia deserta possess both plant growth-promoting and anti-fungal properties, making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases.
分类： 生物学 >> 植物学 分类： 生物学 >> 生物化学 提交时间： 2023-10-23
摘要： 蛋白-蛋白相互作用对于植物细胞生理活动至关重要。为检测和确定两种蛋白之间的相互作用，许多不同的体内和体外方法已被发表。而酵母基于杂交的分裂泛素化（mbSUS）系统是经典的酵母双杂交技术替代方法，它不仅具有酵母双杂交快速便捷的优点，还弥补了传统酵母双杂交法在待测蛋白要求，假阳性率等方面的不足。目前，经过改进的mbSUS法可用于膜蛋白以及可溶性蛋白互作研究，并在植物中用于检测离子通道与膜转运蛋白的互作。本文对mbSUS法技术原理、实验方法以及实验注意事项进行详细描述，为植物蛋白互作研究奠定基础。
分类： 生物学 >> 植物学 提交时间： 2023-10-17 合作期刊: 《干旱区科学》
摘要： Tiger nut is a bioenergy crop planted in arid areas of northern China to supply oil and adjust the planting structure. However, in the western region of Inner Mongolia Autonomous Region, China, less water resources have resulted in a scarcity of available farmland, which has posed a huge obstacle to planting tiger nut. Cultivation of tiger nut on marginal land can effectively solve this problem. To fully unlock the production potential of tiger nut on marginal land, it is crucial for managers to have comprehensive information on the adaptive mechanism and nutrient requirement of tiger nut in different growth periods. This study aims to explore these key information from the perspective of nutrient coordination strategy of tiger nut in different growth periods and their relationship with rhizosphere soil nutrients. Three fertilization treatments including no fertilization (N:P (nitrogen:phosphorous)=0:0), traditional fertilization (N:P=15:15), and additional N fertilizer (N:P=60:15)) were implemented on marginal land in the Dengkou County. Plant and soil samples were collected in three growth periods, including stolon tillering period, tuber expanding period, and tuber mature period. Under no fertilization, there was a significant correlation between N and P contents of tiger nut roots and tubers and the same nutrients in the rhizosphere soil (P<0.05). Carbon (C), N, and P contents of roots were significantly higher than those of leaves (P<0.05), and the C:N ratio of all organs was higher than those under other treatments before tuber maturity (P<0.05). Under traditional fertilization, there was a significant impact on the P content of tiger nut tubers (P<0.05). Under additional N fertilizer, the accumulation rate of N and P was faster in stolons than in tubers (P<0.05) with lower N:P ratio in stolons during the tuber expansion period (P<0.05), but higher N:P ratio in tubers (P<0.05). The limited availability of nutrients in the rhizosphere soil prompts tiger nut to increase the C:N ratio, improving N utilization efficiency, and maintaining N:P ratio in tubers. Elevated N levels in the rhizosphere soil decrease the C:N ratio of tiger nut organs and N:P ratio in stolons, promoting rapid stolon growth and shoot production. Supplementary P is necessary during tuber expansion, while a higher proportion of N in fertilizers is crucial for the aboveground biomass production of tiger nut.
分类： 生物学 >> 植物学 提交时间： 2023-10-17 合作期刊: 《干旱区科学》
摘要： Root pullout performance of plants is an important mechanical basis for soil reinforcement by plant roots in the semi-arid areas. Studies have shown that it is affected by plant factors (species, ages, root geometry, etc.) and soil factors (soil types, soil moisture, soil bulk densities, etc.). However, the effects of loading rates on root pullout performance are not well studied. To explore the mechanical interactions under different loading rates, we conducted pullout tests on Medicago sativa L. and Hippophae rhamnoides L. roots under five loading rates, i.e., 5, 50, 100, 150, and 200 mm/min. In addition, tensile tests were conducted on the roots in diameters of 0.52.0 mm to compare the relationship between root tensile properties and root pullout properties. Results showed that two root failure modes, slippage and breakage, were observed during root pullout tests. All M. sativa roots were pulled out, while 72.2% of H. rhamnoides roots were broken. The maximum fracture diameter and fracture root length of H. rhamnoides were 1.22 mm and 7.44 cm under 100 mm/min loading rate, respectively. Root displacement values were 4.63% (0.43%) and 8.91% (0.52%) of the total root length for M. sativa and H. rhamnoides, respectively. The values of maximum pullout force were 14.6 (0.7) and 17.7 (1.8) N under 100 mm/min for M. sativa and H. rhamnoides, respectively. Values of the maximum pullout strength for M. sativa and H. rhamnoides were 38.38 (5.48) MPa under 150 mm/min and 12.47 (1.43) MPa under 100 mm/min, respectively. Root-soil friction coefficient under 100 mm/min was significantly larger than those under other loading rates for both the two species. Values of the maximum root pullout energy for M. sativa and H. rhamnoides were 87.83 (21.55) mmN under 100 mm/min and 173.53 (38.53) mmN under 200 mm/min, respectively. Root pullout force was significantly related to root diameter (P0.05). Root pullout strength was greater than root tensile strength for the two species. The results suggested that there was no need to deliberately control loading rate in root pullout tests in the semi-arid soil, and root pullout force and pullout strength could be better parameters for root reinforcement model compared with root tensile strength as root pullout force and pullout strength could more realistically reflect the working state of roots in the semi-arid soil.
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