外施硫酸根和蛋氨酸对大豆胱硫醚-γ-合成酶基因GmCGS表达的影响

大豆蛋白中蛋氨酸等含硫氨基酸含量偏低,探究蛋氨酸合成过程关键酶胱硫醚-γ-合成酶编码基因Gm CGS表达规律,对于改善这一缺陷具有十分重要的意义。本研究以过表达At D-CGS转基因大豆株系及其受体品种Jack为材料,从上游物质硫酸根和下游产物蛋氨酸两方面入手,探究硫酸根和蛋氨酸对Gm CGS在转录水平上的影响。结果显示,较高浓度的硫酸根会促进野生型材料中该基因的表达,抑制转基因材料中该基因的表达;蛋氨酸处理之后,对Gm CGS的表达没有显著影响;转基因株系中,Gm CGS表达量显著低于野生型材料中该基因表达量。以上结果说明通过外界硫肥等栽培措施的改变只可以小幅度改变Gm CGS表达量,难以有效改善大豆蛋氨酸含量偏低的缺陷,这为提高大豆蛋氨酸含量提供了一定的理论参考。     

转hrpZ_(Psta)大豆株系的分子检测和抗性分析

为考察转基因大豆株系JN27-119-21后代中hrpZ_(Psta)外源基因的遗传稳定性、检测JN27-119-21后代的抗病能力,从而为培育抗疫霉根腐病的大豆新品种提供理论参考,以转hrpZ_(Psta)基因大豆株系JN27-119-21的T_7、T_8代为供试材料,通过PCR和Southern Blot分子生物学检测方法和下胚轴侵染法鉴定转基因株系后代抗疫霉菌能力。研究结果表明:外源hrpZ_(Psta)基因在高世代转基因株系中能够稳定遗传,hrpZ_(Psta)基因已被成功整合到大豆受体吉农27的基因组中,且整合方式为单拷贝,整合位点不同。hrpZ_(Psta)基因在转化株系的根、茎、叶中均有表达,T_7代平均相对表达量分别为2.877,1.336和7.734,T_8代平均相对表达量分别为3.612、1.746和8.627,2个世代相对表达量水平均为叶根茎。转基因株系后代对疫霉根腐病的抗病级别为抗性,而受体株系为中抗,抗病能力明显提高。     

大豆E3连接酶基因GmPLR-2 的克隆及抗旱功能鉴定

PEG模拟干旱胁迫条件下E3连接酶GmPLR-2 基因在大豆根茎叶中呈上调表达，推测其可能参与大豆抗 旱调节。本研究克隆GmPLR-2 基因，构建植物过表达载体pCAMBIA3301-GmPLR-2、RNA干扰表达载体pCAM⁃ BIA3301-GmPLR-2-RNAi并转化到吉农38中，对T2转基因植株进行分子检测，连续7 d不浇水后测定转基因叶片 中相关生理生化指标。结果表明：共获得T2过表达阳性植株12株，RNA干扰阳性植株11株。干旱胁迫7 d后过表 达植株中相对含水率、POD活性、SOD活性、Pro含量均高于未转化植株，而RNA干扰植株中则低于未转化植株；另 一方面过表达植株中相对电导率、MDA含量均低于未转化植株而RNA干扰植株中含量则高于未转化植株，且差异 极显著，说明GmPLR-2 基因的表达与大豆中相关抗旱指标的变化有关。     

转TaNHX2基因大豆的抗旱性鉴定

本研究利用转TaNHX2基因大豆T3代株系,研究其在干旱胁迫情况下表型、生理特性、生物量与光合作用等方面的变化。结果表明:随着干旱时间的不断延长,对照表现出明显的萎蔫,且转基因植株能够持续地保持绿色状态。转基因植株叶片中含水量高于对照,但株系间叶绿素和可溶性糖含量差异不大,转基因植株中的脯氨酸和丙二醛含量明显低于对照,SOD的活性高于对照。综合评价表明转TaNHX2基因大豆T3代株系比对照具有更强的耐旱性。     

hrpZ_(Psta)在转基因大豆中定量表达与疫霉根腐病和灰斑病抗性相关研究

以T5转hrpZPsta基因大豆JN29-705-15和JL30-187为材料,利用实时荧光定量PCR技术(Quantitative Real Time PCR,qRT-PCR)检测了目标基因在转基因大豆不同组织中的表达量,分别利用下胚轴侵染法和叶面喷施法鉴定疫霉根腐病抗性和灰斑病抗性,并分析目的基因表达量与疫霉根腐病和灰斑病抗性的相关性。结果表明:hrpZPsta基因在大豆的叶、茎、根、籽粒中均有表达,二个株系平均相对表达量分别为8.2/6.1、0.9/0.7、6.5/4.6和0.8/0.7;T5转hrpZPsta基因大豆抗疫霉根腐病和灰斑病能力与野生型相比均有所提高,JN29-705-15对疫霉根腐病抗性从感病提高到中抗,而JL30-187从中抗提高到抗病;hrpZPsta基因在叶中的表达量也与抗灰斑病能力呈正相关,与病情级别呈极显著负相关。试验结果初步证明了外源基因hrp ZPsta在大豆植株中的表达量与受体植株对疫霉根腐病和灰斑病抗性存在一定的相关性。     

过表达GmXTH1基因大豆对干旱胁迫的生理生化响应

为研究GmXTH基因对干旱胁迫大豆苗期表型和生理生化特征的影响,以转基因受体大豆品种M18、GmXTH1过表达转基因株系OEA1和OEA2、GmXTH1干扰表达转基因株系IEA1和IEA2为试验材料,采用盆栽法,设置3种不同水分处理,对苗期不同转化株系的表型、RWC、SOD活性、POD活性和MDA含量进行测定.结果 表明:随干旱胁迫程度增加,不同转化株系的RWC相对降低,SOD和POD活性先增加后减少,MDA含量增加.相同干旱胁迫条件下,与对照品种M18相比,转GmXTH1基因过表达材料OEA1和OEA2的RWC较高,SOD和POD活性相对较高,响应速度较快,MDA含量较低,增长率相对较低,叶色浓绿、茎秆粗壮和株型整体表现较好,胁迫后复水恢复快.GmXTH1基因干扰表达材料IEA1和IEA2的表现则相反,植株受干旱胁迫后,整体表现为叶片萎蔫,茎秆枯细,株型整体表现较差,RWC、SOD和POD活性相对较低,响应速度较慢.说明GmXTH1基因的过量表达对与大豆植株抗旱相关的生理生化指标有积极影响,GmXTH1基因可能参与大豆的抗旱应答反应过程.     

GmRACK1基因对大豆耐旱性调控作用研究

活化C激酶1受体(RACK1)属于含有色氨酸-天冬氨酸结构域(WD)重复结构的蛋白质亚家族.为研究GmRACK1在干旱胁迫中的调控作用,本研究构建GmRACK1基因过表达与沉默两种双元表达载体并转化大豆,对转基因和对照大豆株系进行干旱和复水处理,测定株系的干重、存活率、叶绿素含量、过氧化氢含量和抗氧化酶活性等指标;分析GmRACK1基因对大豆抗旱性的调控作用.结果 显示:在干旱胁迫下,大豆GmRACK1基因沉默株系(RNAi)的存活率和干重明显高于野生型(WT)和过表达(OE)株系.干旱10 d后RNAi株系的叶绿素含量显著高于WT和OE株系,OE株系的DAB和NBT染色颜色比WT和RNAi株系深.土壤干旱胁迫10 d后复水4d,RNAi株系恢复好于WT和OE株系.在15％ PEG 4000处理下,RNAi株系抗氧化物酶SOD、POD和CAT的活性和ABA含量显著高于WT和OE株系,而MDA和电导率显著低于WT和OE株系.结果 说明RNAi株系能清除过多活性氧,导致植物的氧化伤害减弱.GmRACK1基因对大豆耐旱性存在调控作用.     

大豆GmPRP转基因拟南芥抗盐性鉴定

为研究大豆脯氨酸富集蛋白基因Gm PRP在植物应对盐胁迫中的作用,利用前期克隆的Gm PRP基因,以p PZP为植物表达载体,构建了由组成型启动子Ca MV35S驱动Gm PRP基因的植物表达载体。通过Floral dip法对拟南芥进行遗传转化,获得7株阳性转基因株系。盐处理后,转基因拟南芥的种子萌发率高于野生型且叶片中丙二醛含量极显著低于野生型,表明Gm PRP提高了转基因拟南芥的抗盐性。     

转NPR1和CHR3抗病基因提高大豆对疫霉根腐病抗性研究

为检测GmCHR3和广谱抗病基因NPR1双抗基因转化到大豆吉林30中的遗传稳定性和抗病能力,从而为培育出抵抗疫霉根腐病大豆新品种提供有效参考,以大豆品种吉林30转CHR3抗病基因转化品系JL30+GmCHR3为目标受体材料,以吉林30为对照受体材料,利用农杆菌介导法将NPR1导入受体中.利用常规PCR检测基因转化情况,利用Southern杂交和qRT-PCR技术分别鉴定JL30+GmCHR3受体和双抗基因转化株系T1和T2代中两个基因的整合和表达情况,采用下胚轴侵染法鉴定转基因大豆植株对疫霉根腐病的抗性.PCR研究结果显示:转化元件的启动子35s、终止子Nos、筛选标记基因Bar以及目的基因NPR1全部转入到受体基因组中;NPR1基因以单拷贝的形式在转化植株中完成整合;NPR1基因在大豆植株根、茎和叶中均有表达,其中T1代株系在3个部位的相对表达量分别是2.732,1.614和3.316,T2代株系的相对表达量分别是2.936,2.084和3.864;NPR1基因在各组织中的相对表达量为茎＜根＜叶.CHR3和NPR1双抗基因转化株系对疫霉根腐病表现为高抗,NPR1单抗基因转化株系表现为中抗,非转基因吉林30植株表现为感病.结果说明大豆吉林30转入双价抗病基因GmCHR3和NPR1可以增强其对疫霉根腐病的抗性.     

转GmHAP3-17基因大豆的抗旱性分析

Gm HAP3-17基因是一个与At HAP3-1同源的转录因子,本研究利用超表达Gm HAP3-17大豆,在模拟干旱条件下以及田间干旱试验下进行了转基因大豆的抗旱性分析。结果显示:在大棚盆栽模拟干旱胁迫条件下,转基因大豆H16、H18、H26比野生型大豆WT根系发达,主根长且侧根较多,植株生长状态比对照好,叶片枯萎发生较迟、程度较轻。转基因大豆与野生型相比,MDA含量低,叶片伤害度较轻,叶片含水量较高。进一步研究表明,在田间自然干旱胁迫下,转基因大豆同样表现出较好的生长状况,较低的叶片伤害度和较高的叶片含水量。在自然干旱条件下,与野生型大豆相比,转Gm HAP3-17基因大豆表现为根系发达、扎根深、侧根多,增加了株高、主茎节数、有效分枝数。H26株系的有效荚数、单株粒数、单株粒重、百粒重均比野生型提高明显,表现出了显著的产量优势。上述结果表明:GmHAP3-17基因具有正调控干旱的功能,因而该基因将成为培育抗旱转基因作物的一个有效的基因资源。     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

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Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

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Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems,and Other Miscellaneous Mechanisms of Action

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.     

Effects of Micronutrient Deficiencies on Human Health: Its Status in South Asia

SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.     

Citrus Flavonoids in Fruit and Traditional Chinese Medicinal Food Ingredients in China

Flavonoids-enriched tissues of citrus such as peel, immature fruit and flower are consumed as culinary seasonings, tea ingredients in China for centuries. This HPLC quantitative study on the five citrus flavonoids, naringin, hesperidin, neohesperidin, sinensetin and nobiletin on a wide range of Chinese citrus fruits and several Traditional Chinese Medicinal food ingredients in East China, revealed a great diversity in flavonoid composition. Huyou peel (C. paradisi cv. Changshanhuyou) was found to be the best naringin (3.25%) and neohesperidin (2.76%) source; C. aurantium, a major ingredient of several citrus-related TCM, is also a suitable source of naringin and neohesperidin, and a good juice source for flavanone glycosides; the peel of Wenzhoumiju (C. unshiu) is one of the richest local species in hesperidin (up to 6.25%); Zaoju (C. subcompressa) has the highest content of nobiletin (0.59%), a polymethoxylated flavone. LC-ES-MS analysis of Zanthoxylum genus for flavonoids revealed for the first time the presence of significant amounts (0.74%) of hesperidin in the root of Liangmianzhen (Z. nitidum (Roxb.) DC), a relative of Sichuan pepper, which is a spice widely used in China.     

Evolutionary aspects of the trade-off between seed size and number in crops

Whereas the concept that availability of resources drives seed production is sound in principle, it is incomplete as there are many solutions to the allocation of resources that derive from the trade-off between number and size. This paper examines evolutionary aspects of this trade-off in annual grain crops. The analysis is centred on the working hypotheses that, for a given species and environment, allocation of resources to reproduction involves (H1) high plasticity in seed number, which allows for variable resource availability, and (H2) a relatively narrow range of seed size that results from evolutionary and agronomic selection. Comparisons between crops and fish are used to highlight common evolutionary elements in taxa where parents provide little or no care to their offspring, with the consequence that both number and early survival of offspring, hence fitness of parents, are partially related to embryo size and reserves.

The plasticity of seed number in relation to availability of resources is analysed against the established relationship between offspring number and parent growth rate during critical stages. The notion that seed size is under stabilising selection is analysed against three conditions: (1) mean seed size is conservative for a given species and environment, (2) seed size affects fitness, and (3) seed size is heritable. Databases from published papers were compiled to analyse the relative variability of seed size and number, and the heritability of seed size. Evidence for and against the link between seed size and parental fitness is revised using the Smith–Fretwell model as framework (Am. Nat., 108, 499–506).

The proposal of high plasticity of seed number and narrow variability of seed size resulting from stabilising natural selection is generally consistent with evolutionary and genetic considerations. Agronomic selection may have reinforced natural selection leading to relatively narrow seed size in species such as wheat and soybean, where cultivated types retained high plasticity for seed number. In contrast, selection for one or few inflorescences in crops like sunflower and maize may have morphologically reduced seed number plasticity and increased variability of seed size and its responsiveness to resource availability in relation to their wild ancestors.     

Management of Soil Micronutrient Deficiencies in the Rice-Wheat Cropping System

Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.