Response of root morphology, physiology and endogenous hormones in maize(Zea mays L.) to potassium deficiency

Potassium （K） deficiency is one of the major abiotic stresses which has drastically influenced maize growth and yield around the world. However, the physiological mechanism of K deficiency tolerance is not yet fully understood. To identify the differences of root morphology, physiology and endogenous hormones at different growing stages, two maize inbred lines 90-21-3 （tolerance to K deficiency） and D937 （sensitive to K deficiency） were cultivated in the long-term K fertilizer experimental pool under high potassium （＋K） and low potassium （-K） treatments. The results indicated that the root length, volume and surface area of 90-21-3 were significantly higher than those of D937 under -K treatment at different growing stages. It was noteworthy that the lateral roots of 90-21-3 were dramatically higher than those of D937 at tasselling and flowering stage under-K treatment. Meanwhile, the values of superoxide dismutase （SOD） and oxidizing force of 90-21-3 were apparently higher than those of D937, whereas malondialdehyde （MDA） content of D937 was obviously increased. Compared with ＋K treatment, the indole-3-acetic acid （IAA） content of 90-21-3 was largely increased under-K treatment, whereas it was sharply decreased in D937. On the contrary, abscisic acid （ABA） content of 90-21-3 was slightly increased, but that of D937 was significantly increased. The zeatin riboside （ZR） content of 90-21-3 was significantly decreased, while that of D937 was relatively increased. These results indicated that the endogenous hormones were stimulated in 90-21-3 to adjust lateral root development and to maintain the physiology function thereby alleviating K deficiency.

Effect of Potassium Deficiency on Root Growth and Nutrient Uptake in Maize (Zea mays L.)

Potassium (K) is an essential nutrient on the growth and development for maize (Zea Mays L.). And the developed root morphology and root activity have great significance to nutrient absorption and play an important role in the growth and development of plants. To explore the response to K-deficiency on root growth and nutrient absorption of maize, two inbred lines, 90-21-3 (Tolerance to K deficiency) and D937 (Sensitive to K deficiency) were carried out to investigate the root morphology, root activity, nutrient uptake and related traits. The results showed that K-deficiency inhibited the root growth of 90-21-3 and D937, but increased the ratio of root to shoot (R/S). The total length, root surface area, the root diameter and root volume of root system of 90-21-3 and D937 were significantly decreased by K deficiency, especially the fine root (0 - 0.4 mm) in root length and root surface area. In addition, the K concentration of root in the two lines was significantly decreased, but root activity was significantly improved, which promoted the absorption of the root system to Na+. Compared with D937, 90-21-3 was able to distribute more carbohydrates from shoot to the root system under K deficiency, alleviating the inhibition of root growth. The fine root system was the main part for absorption nutrient. The length and surface area of 90-12-3 were no difference, and significantly decreased by 12.90% and 17.65% in D937 after 5 d of K deficiency. As well, the root activity of 90-21-3 was significantly increased when encountered to K deficiency, which promoted the accumulation of Na+ and Ca2+ and regulated the osmotic stress. Therefore, it could be a responding mechanism for tolerance crop by maintaining large root system, increasing root activity and adjusting nutrient absorption to adapt to K deficiency.

Effect of Zn deficiency and excessive bicarbonate on the allocation and exudation of organic acids in two Moraceae plants

The effect of zinc(Zn) deficiency and excessive bicarbonate on the allocation and exudation of organic acids in plant organs(root, stem, and leaf) and root exudates of two Moraceae plants(Broussonetia papyrifera and Morus alba) were investigated. Two Moraceae plants were hydroponically grown and cultured in nutrient solution in four different treatments with 0.02 mM Zn or no Zn,combined with no or 10 mM bicarbonate. The variations of organic acids in different plant organs were similar to those of root exudates in the four treatments except B. papyrifera, which was in a treatment that was a combination of 0.02 mM Zn and no bicarbonate. The response characteristics in the production, translocation, and allocation of organic acids in the plant organs and root exudates varied with species and treatments. Organic acids in plant organs and root exudates increased under Zn-deficient conditions,excessive bicarbonate, or both. An increase of organic acids in the leaves resulted in an increase of root-exuded organic acids. B. papyrifera translocated more oxalate and citrate from the roots to the rhizosphere than M. alba under the dual influence of 10 mM bicarbonate and Zn deficiency. Organic acids of leaves may be derived from dark respiration and photorespiration. By comparison, organic acids in stems, roots, and root exudates may be derived from dark respiration and organic acid translocation from the leaves. These results provide evidence for the selective adaptation of plants to environments with low Zn levels or high bicarbonate levels such as a karst ecosystem.

Identification of suitable reference genes in leaves and roots of rapeseed (Brassica napus L.) under different nutrient deficiencies

Nutrient deficiency stresses often occur simultaneously in soil. Thus, it＇s necessary to investigate the mechanisms underlying plant responses to multiple stresses through identification of some key stress-responsive genes. Quantitative real-time PCR （qRT-PCR） is essential for detecting the expression of the interested genes, of which the selection of suitable reference genes is a crucial step before qRT-PCR. To date, reliable reference genes to normalize qRT-PCR data under different nutrient deficiencies have not been reported in plants. In this study, expression of ten candidate reference genes was detected in leaves and roots of rapeseed （Brassica napus L.） after implementing different nutrient deficiencies for 14 days. These candidate genes, included two traditionally used reference genes and eight genes selected from an RNA- Seq dataset. Two software packages （GeNorm, NormFinder） were employed to evaluate candidate gene stability. Results showed that VHA-E1 was the highest-ranked gene in leaves of nutrient-deficient rapeseed, while VHA-G1 and UBC21 were most stable in nutrient-deficient roots. When rapeseed leaves and roots were combined, UBC21, HTB1, VHA-G1 and A CT7 were most stable among all samples. To evaluate the stabilities of the highest-ranked genes, the relative expression of two target genes, BnTrxl;1 and BnPhtl;3 Were further determined. The results showed that the relative expression of BnTrxl;1 depended on reference gene selection, suggesting that it＇s necessary to evaluate the stability of reference gene prior to qRT-PCR. This study provides suitable reference genes for gene expression analysis of rapeseed responses to different nutrient deficiencies, which is essential for elucidation of mechanisms underlying rapeseed responses to multiple nutrient deficiency stresses

Clinical experimental study of Arnebia Root oil in increasing FGF expression and promoting wound surface healing

Objective：To investigate the effection of Arnebia Root oil on the FGF expression in wound surface and the ability to promote wound surface healing. Methods：24 wound surfaces of patients were divided into two groups. Experimental group was treated by Arnebia Root oil and the control was treated by petrolatum gauze. Histology, histochemistry, electron microscope methods and healing rate measurement were used to show the FGF expression and wound healing process. Results：Endogenous FGF were expressed in both of the groups, in which of the experimental group was higher than that of the control group, the wound surface healing rate of experimental group was also higher and paralleled with FGF expression. Conclusion：Arnebia Root oil has effects to promote FGF expression and enhances wound surface repair. The wound healing mechanism between the action of Arnebia Root oil and function of FGF need further investigating.

Changes in Osmotic Adjustment and Antioxidant Enzyme in Maize (<i>Zea mays L.</i>) Root Exposed to K Deficiency

Potassium (K) deficiency damaged membrane stability through irregular reactive oxygen species (ROS) caused by K deficiency stress while osmotic adjustment and antioxidant capacities play an essential role in preventing plants from osmotic stress and oxidative damages. To investigate the difference of osmoprotectants and antioxidant enzyme activities in the root, two representative maize varieties, 90-21-3 (K-tolerant) and D937 (K-sensitive), were hydroponically cultivated under normal K (+K) and K deficiency (-K) treatments in Shenyang Agriculture University, China. The results showed that root accumulation, soluble protein in root of 90-21-3 and D937 were decreased under K deficiency stress, but the root to shoot ratio, proline, free amino acid, soluble sugar, reactive oxygen species (ROS) in root for both genotypes were increased. Compared with the root of D937, the root of 90-21-3 was able to swiftly accumulate more proline, free amino acid and soluble sugar in the root when encountering K deficiency. The antioxidant enzyme activity in the root of 90-21-3, including superoxide dismutase (SOD), and catalase (CAT), peroxidase (POD), were significantly increased to counter increased levels of O2·- and H2O2 under K deficiency stress. The presented results indicated that osmotic regulator and antioxidant enzyme were actively responded to K deficiency stress, 90-21-3 (K-tolerant maize) accumulated more osmoprotectants and enhanced the activity of antioxidant enzymes to degrade ROS, alleviating oxidative stress.

Plasticity of wheat seedling responses to K^(+) deficiency highlighted by integrated phenotyping of roots and root hairs over the whole root system

The availability in the soil of potassium(K^(+)),a poorly mobile macronutrient required in large quantities for plant growth,is generally suboptimal for crop production in the absence of fertilization,making improvement of the ability of crops to adapt to K^(+)deficiency stress a major issue.Increasing the uptake capacity of the root system is among the main strategies to achieve this goal.Here,we report an integrative approach to examine the effect of K^(+)deficiency on the development of young plant entire root system,including root hairs which are known to provide a significant contribution to the uptake of poorly mobile nutrients such as K^(+),in two genetically distant wheat varieties.A rhizobox-type methodology was developed to obtain highly-resolved images of root and root hairs,allowing to describe global root and root hair traits over the whole root system via image analysis procedures.The two wheat varieties responded differently to the K^(+)shortage:Escandia,a wheat ancestor,reduced shoot biomass in condition of K^(+)shortage and substantially increased the surface area of its root system,specifically by increasing the total root hair area.Oued Zenati,a landrace,conversely appeared unresponsive to the K^(+)shortage but was shown to constitutively express,independently of the external K^(+)availability,favorable traits to cope with reduced K^(+)availability,among which a high total root hair area.Thus,valuable information on root system adaptation to K^(+)deficiency was provided by global analyses including root hairs,which should also be relevant for other nutrient stresses.

Nutrient Deficiency Affects Root Architecture of Young Seedlings of Malus hupehensis (Pamp) Rehd. Under Conditions of Artificial Medium Cultivation

What the researchers go in for is to establish models between root architecture （RA） changes and nutrition, mold ideal root architecture of apple trees, improve the nutrient uptake efficiency, and further explore the functional mechanism of nutrient elements during the course of RA construction. The cultivation system of filter paper is utilized to research the effect of nutrient deficiency on the RA of Malus hupehensis （Pamp.） Rehd. There may be eight types of RA. In complete Hogland solution, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂. With the lack of P, K or Ca, the main type of RA is ＂lateral roots clustering in the upper region primary root＂, and the ＂lateral roots clustering in the upper and middle regions of primary root＂ types of RA decrease. But with shortage of P, the type of lateral roots clustering in the upper and lower regions of primary root increases, and the type of lateral roots clustering in the middle region of primary root decreases, with the types of RA diversified. Under the condition of K deficiency, the type of no lateral root increases and types of lateral roots clustering in the middle region of primary root decrease, and the percentage of such types as ＂no lateral root＂, ＂lateral roots clustering in the upper region of primary root＂, and ＂lateral roots clustering in the upper and middle regions of primary root＂ accounts for 97.9% in all, with the types of RA simplified. With lack of Fe, Mg or Zn, the main type of RA is ＂lateral roots clustering in the upper and middle regions of primary root＂, but the type of lateral roots evenly-distributed on primary root increases. The main type of RA is ＂lateral roots evenlydistributed on primary root＂, under the condition of N deficiency, and the types of RA turn out to be diversified. There exists a close relation between nutrient deficiency and RA changes. Owing to various forms of nutrient deficiency, correspondingly different types of RA have been produced.

Development of Root Phenotyping Platforms for Identification of Root Architecture Mutations in EMS-Induced and Low-Path-Sequenced Sorghum Mutant Population

Sorghum’s natural adaptation to a wide range of abiotic stresses provides diverse genetic reserves for potential improvement in crop stress tolerance. Growing interest in sorghum research has led to the expansion of genetic resources though establishment of the sorghum association panel (SAP), generation of mutagenized populations, and recombinant inbred line (RIL) populations, etc. Despite rapid improvement in biotechnological tools, lack of efficient phenotyping platforms remains one of the major obstacles in utilizing these genetic resources. Scarcity of efforts in root system phenotyping hinders identification and integration of the superior root traits advantageous to stress tolerance. Here, we explored multiple approaches in root phenotyping of an ethyl methanesulfonate (EMS)-mutagenized sorghum population. Paper-based growth pouches (PGP) and hydroponics were employed to analyze root system architecture (RSA) variations induced by mutations and to test root development flexibility in response to phosphorus deficiency in early growing stages. PGP method had improved capabilities compared to hydroponics providing inexpensive, space-saving, and high-throughput phenotyping of sorghum roots. Preliminary observation revealed distinct phenotypic variations which were qualitatively and quantitatively systemized for association analysis. Phenotypes/ideotypes with root architecture variations potentially correlated with Pi acquisition were selected to evaluate their contribution to P-efficiency (PE). Sand mixed with P-loaded activated alumina substrate (SAS) provided closely to natural but still controlled single-variable conditions with regulated Pi availability. Due to higher labor and cost input we propose SAS to be used for evaluating selected sorghum candidates for PE. The ability of rapidly screening root phenotypes holds great potential for discovering genes responsible for relevant root traits and utilizing mutations to improve nutrient efficiency and crop productivity.

防己黄芪汤联合穴位埋线治疗脾虚痰湿型单纯性肥胖的回顾性队列研究

目的:观察防己黄芪汤联合穴位埋线治疗脾虚痰湿型单纯性肥胖的疗效与安全性。方法:采用回顾性队列研究方法,选取上海市嘉定区中医医院代谢与肥胖专病门诊收治的单纯性肥胖患者,最终纳入统计分析共175例,其中治疗组95例,对照组80例。治疗组予以防己黄芪汤联合穴位埋线治疗,对照组予以二甲双胍缓释片治疗,疗程3个月,观察患者体质量、腰围、BMI、减重结局、中医证候疗效等主要指标;胰岛素抵抗指数(HOMA-IR)、糖化血红蛋白(HbA1c)和血脂等次要指标;肝肾功能等安全性指标。结果:与对照组比较,治疗组患者随时间的延长,体质量、BMI、腰围明显下降,达到临床减重结局的发生率明显更高,且治疗组HOMA-IR、HbA1c、甘油三酯等指标明显改善(P<0.05)。中医证候疗效方面,治疗组总有效率89.47%(85/95),优于对照组51.25%(41/80),差异具有统计学意义(P<0.05)。治疗过程中两组患者均未见肝肾功能异常。结论:防己黄芪汤联合穴位埋线可明显减轻患者体质量,改善血糖和胰岛素抵抗以及脂代谢,患者依从性良好,具有较好的安全性。

胡志俊基于“虚损为本,瘀毒为标”论治腰椎间盘突出症经验介绍

胡志俊教授将腰椎间盘突出症的病机总结为“虚损为本,瘀毒为标”,虚、瘀、毒三者逐渐进展而又互相影响,最终形成虚、瘀、毒三者互致的病机演变状态。辨证论治,结合患者就诊时的疾病状态,予以疏筋解结化瘀毒、益肾壮骨补内虚等法治疗,并创复元康体操指导患者功法锻炼,临床疗效显著。

马丽俐教授从脾论治瘾疹思路与用药经验

[目的]总结马丽俐教授从脾论治瘾疹的经验,为临床提供参考。[方法]通过临证收集和记录门诊病历,整理马教授从脾辨证论治瘾疹的经验,总结本病的病因病机及遣方用药规律,并举医案一则加以佐证。[结果]马教授认为,瘾疹的核心病机为脾虚失运,感邪致病,总属正虚邪中,本虚标实,临证常见脾虚营卫失和、脾虚湿困、脾虚肝郁。治疗上马教授灵活运用补运二法以健脾体,以调和营卫、运脾化湿、补土疏木分治,同时注重因人制宜,个体化论治。所举验案中患者年逾花甲,皮疹反复,诊断其为脾虚湿蕴之瘾疹,治宜运脾祛湿、祛邪止痒,后期兼扶正补虚,随症加减,用药灵活,疗效显著。[结论]马教授秉承以脾为本的辨治思想施治瘾疹,疗效明显,其经验值得借鉴和推广。

基于整体观辨治原发性高血压的思路

原发性高血压(EH)作为一种异质性疾病,一般认为是在一定的遗传易感性基础上由多种环境因素综合作用的结果,该认识与中医整体观辨治疾病具有高度的相似性。基于中医整体观进一步阐释EH发病学特点及其病理生理演变的内在机制,为中西医结合防治EH提供新的视角。并根据整体观思维提出行之有效的防治EH的策略,对构建中西医并重的EH慢病防治体系具有重要意义。

从脾肾关系探讨糖尿病肾病防治思路

糖尿病肾病是临床常见糖尿病并发症,为终末期肾病的主要病因。糖尿病肾病归属于中医学消渴病继发的水肿、尿浊等范畴,其病因为禀赋不足、饮食不节等,以多食、多饮、多尿和体质量减少、尿浊为主要表现,病机虚实错杂。基于脾肾相关理论探讨糖尿病肾病发生之病因病机,认为脾肾虚损、水津失制是该病发生的根本病机,多伴随脾肾两虚,或有水液代谢失常、血脉瘀滞。从健脾制水、温土制水、固本培元三个角度系统总结脾肾二脏在糖尿病临床辨治过程中的具体应用,以期为中医防治糖尿病肾病提供新的思路和借鉴。

陈博来基于“肾为生痰之本”辨治肾虚痰阻型腰痛

肾主水,为先天之本,对于体内津液的运行输布具有重要作用,且肾与水腑膀胱互为表里,通过冲脉与“水谷之海”的胃有经络上的联系,故肾在痰的生成中起着关键作用。陈博来教授认为,肾虚痰阻型腰痛为本虚标实之证,“痰阻”为其标,“肾虚”为其本,临床以腰骶钝痛、痛处固定、腰部僵硬、肢体麻木或偏枯为主要特点,兼见腰膝酸软、喜按喜揉等表现。肾虚痰阻型腰痛的治疗可基于“肾为生痰之本”,以补肾祛痰为法,拟定理痰汤(主要组成药物为芡实、半夏、黑芝麻、柏子仁、白芍、陈皮、茯苓等)为基础方,针对不同兼症辅以健脾、宣肺等药进行加减治疗。其辨治思路可为临床中医治疗腰痛提供参考。

Mechanisms of vacuolar phosphate efflux supporting soybean root hair growth in response to phosphate deficiency

Phosphorus is an essential macronutrient for plant growth and development.In response to phosphate(Pi)deficiency,plants rapidly produce a substitutive amount of root hairs;however,the mechanisms underlying Pi supply for root hair growth remain unclear.Here,we observed that soybean(Glycine max)plants maintain a consistent level of Pi within root hairs even under external Pi deficiency.We therefore investigated the role of vacuole-stored Pi,a major Pi reservoir in plant cells,in supporting root hair growth under Pi-deficient conditions.Our findings indicated that two vacuolar Pi efflux(VPE)transporters,GmVPE1 and GmVPE2,remobilize vacuolar stored Pi to sustain cytosolic Pi content in root hair cells.Genetic analysis showed that double mutants of GmVPE1 and GmVPE2 exhibited reduced root hair growth under low Pi conditions.Moreover,GmVPE1 and GmVPE2 were highly expressed in root hairs,with their expression levels significantly upregulated by low Pi treatment.Further analysis revealed that GmRSL2(ROOT HAIR DEFECTIVE 6-like 2),a transcription factor involved in root hair morphogenesis,directly binds to the promoter regions of GmVPE1 and GmVPE2,and promotes their expressions under low Pi conditions.Additionally,mutants lacking both GmRSL2 and its homolog GmRSL3 exhibited impaired root hair growth under low Pi stress,which was rescued by overexpressing either GmVPE1 or GmVPE2.Taken together,our study has identified a module comprising vacuolar Pi exporters and transcription factors responsible for remobilizing vacuolar Pi to support root hair growth in response to Pi deficiency in soybean.

探讨哮喘之宿根

哮喘是一种由气道挛急所致的气喘痰鸣疾患,中医认为哮喘难以治愈、反复发作的根本与其“宿根”未除密切相关。作者通过查阅古今文献,总结出哮喘宿根有“痰”“瘀血”“痰瘀”“肺脾肾虚”“肝风”“客邪”“湿邪”等,创新性地提出哮喘各宿根相互影响、相互作用、互为因果,从而形成恶性循环,为临床上多角度、多层次辨治哮喘提供了新思路。

从“痰涎本皆血气”认识痴呆补肾祛痰之治法

肾虚与痰浊是痴呆形成的关键因素,痴呆患者肾虚不能生髓,元气不充不能化水,遂致痰实为标,阻滞气血、脑窍,发为痴呆。张景岳谓痰涎与血气本属一源,在元气未充之时,水饮化失其正,血气即成痰涎,故在治疗上应补肾与祛痰并举,因为痰涎与血气本属一源,只有正本清源,恢复肾主水的生理功能,痰涎才会化得其正。临床有医家在治疗痴呆患者的过程中谓补肾会助生痰涎,倡导先祛痰实,再补肾虚,实是未得痰涎本皆血气之意。

基于AHP-隶属函数法的棉花子叶期耐低钾能力鉴定

挖掘和利用钾高效种质资源、提高钾营养利用效率是解决棉花生产中缺钾问题的重要途经,为建立快速可靠的耐低钾评价体系,应用决策评价模型AHP-隶属函数法在子叶期对384份棉花种质材料进行耐低钾评价。结果表明:缺钾条件下(0.03 mmol L^(–1)),子叶缺钾斑相对面积的变异系数最大(96.24%),植株干重变异系数最小(14.73%),子叶与下胚轴夹角、根长、根表面积、根体积、K^(+)浓度、K~+积累量的变异系数在15.72%~31.52%之间。子叶与下胚轴夹角与缺钾斑相对面积显著负相关;根系形态与植株干重和K~+积累量显著正相关。经AHP-隶属函数法评价,384份棉花种质材料的综合评价值C分布于0.25~0.79之间,其中无极一枝花(C=0.7868)耐低钾能力最强,巴西014(C=0.2451)耐低钾能力最弱。系统聚类显示,高度(C值为0.74~0.79)和中度(C值为0.33~0.69)耐低钾材料的占比分别为1.30%和95.31%,低钾敏感材料(C值为0.25~0.33)占比3.39%。种子K~+浓度与子叶期耐低钾能力之间的相关性不显著。本研究完善了棉花耐低钾种质资源筛选体系,对384份供试种质的子叶期耐低钾能力进行了鉴定,筛选出5份耐低钾能力强的种质(无极一枝花、棕1-61、黑山棉1号、秦荔514、苏联棉78系),研究具有一定的理论和应用价值。

基于“一气周流”论治胸痹心痛理论探讨及验案举隅

中医药在胸痹心痛的治疗中积累了丰富的经验,而“一气周流”理论为其提供了新的治疗思路。该文首先从“一气周流”的学术内涵出发,分析了胸痹心痛的病机,主要包括阳虚毒聚、血脉痹阻及枢机不利、木郁土败等因素。基于此,该文提出了阳虚宜温、郁滞宜疏等治疗策略,并例举医案一则,证明采用“一气周流”理论指导治疗胸痹心痛,可以有效缓解症状,提高疗效,为中医治疗胸痹心痛提供了新的理论依据和临床指导。