Lack of 26 kDa globulin accompanies increased free amino acid content in rice (Oryza sativa L.) grains

Seed nitrogen content, protein composition and free amino acid content were determined in rice mutant lines with altered storage protein composition and their parental cultivars. The Lgc1 gene, which causes low glutelin content and high content of 13 kDa prolamin and 26 kDa globulin, did not affect grain weight, nitrogen content, or free amino acid content. The glb1 gene, which lacks the 26 kDa globulin, did not affect grain weight or nitrogen content, but in mutant lines with glb1 gene the content of the major free amino acids was significantly (1.3–1.5 times) higher than those of their parental cultivars. These results suggest that absence of 26 kDa globulin is accompanied by an accumulation of a high level of free amino acids in rice grains.     

燕麦PRR基因家族鉴定与表达分析

春、夏播燕麦是长日照作物，光周期不敏感燕麦的创制使其在短日照条件下能正常生长发育。PRR基因是光周期途径中重要的昼夜节律调节基因。前期转录组研究表明PRR基因可能与燕麦光周期不敏感性有关。本研究从转录组和全基因组水平对燕麦PRR基因家族进行鉴定、生物信息学分析和表达研究。结果表明，在燕麦转录组和基因组水平分别鉴定到6个和2个PRR基因，均包含REC和CCT结构域；进化分析表明燕麦PRR基因与小麦、大麦、黑麦草和山羊草的亲缘关系较近；燕麦PRR基因启动子区域包含与光响应、生长发育和胁迫相关的顺式作用元件；qRT-PCR分析表明燕麦PRR基因的表达具有节律特征，全生育期过程中AsPRR1和AsPRR2在穗和叶的表达量均呈现由低到高、下降后再升高的双峰趋势，且AsPRR2基因的表达量高于AsPRR1。以上结果说明，AsPRR基因在燕麦光周期途径中发挥负调控作用，其下调表达促进了光周期不敏感性燕麦gp012在短日照条件下开花。本研究为揭示AsPRR基因在燕麦光周期不敏感机制中的作用奠定 了基础。     

玉米CLC家族基因差异表达及其与NO3-、Cl-吸收之间的关系

通过对CLC基因家族7个基因的蛋白序列比对,发现他们具有比较高的同源性,在玉米苗期用KNO3、Na Cl、PEG对其进行处理,分别在处理1、4、8、16、24、36 h后检测其体内NO3-、Cl-的浓度,同时取上述几个时间段处理的玉米根和叶,用q PCR检测CLC家族基因的表达量,研究玉米硝态氮吸收与CLC基因表达量之间的关系。结果表明,综合玉米中NO3-、Cl-的变化与CLC家族基因表达量的变化,明确在KNO3、Na Cl、PEG处理下CLC家族基因表达量变化的规律,BT066984.1、GQ412103.1、NM001176231.1和NM001136935.2这4个基因对硝酸盐的响应明显,很可能具有运输硝酸盐的作用。     

小麦抗条锈基因Yr10的抗病通路研究

小麦抗条锈病基因Yr10作为全生育期抗性基因,对国内大部分的条锈菌生理小种表现抗性,为探究Yr10介导的抗病通路,以小麦AvocetS(AvS)和其近等基因系AvS Yr10NIL(AvS+ Yr10)为材料,接种条锈菌CYR31后分别构成亲和与非亲和体系,通过分析含有抗病基因Yr10非亲和体系中的信号分子变化,比较非...     

Photoperiodic Regulationof Apical Growth Cessation in Northern Tree Species

Summary

Tree species adapted to the climatic conditions of the northern boreal and subarctic vegetation zones have a capacity to develop a very high level of frost hardiness, even to survive the temperature of liquid nitrogen in midwinter. Proper timing of hardening, as well as of dehardening, is crucial for winter survival of these species. In northern tree species, cessation of apical elongation growth and bud set is a prerequisite for developmental and metabolic processes leading to hardening, and this chain of events is induced by photoperiod. The northern tree species are closely adapted to the local light climate and display photoperiodic ecotypes. The critical photoperiod is under genetic control and increases with increasing latitude of origin of the eco-type. The photoperiod is probably perceived by the phytochrome system, but the role of other pigment systems, like cryptochrome, has not been studied in woody plants. Phytochrome genes have been cloned from both conifers and deciduous species, but so far we do not have any information about possible differences between photoperiodic ecotypes at the phytochrome level. Northern and southern ecotypes have different responses to red:far red ratios, which could indicate differences in composition of their phytochrome systems, for example, the proportions of phytochrome A and B. Both phytochrome A and phytochrome B can be involved in photoperiodic responses. Experiments with transgenic hybrid aspen suggest that responses to photoperiod could be affected by the amount of phytochrome A present in plants. In deciduous species, the plant hormone gibberellin A₁ (GA1) can completely substitute for a long photoperiod, and short day induced cessation of growth is preceded by a significant reduction of GA1 levels, particularly in the elongation zone. Photoperiodic control of GA metabolism is supported by several studies, but very little is known about the interaction between phytochrome and GA metabolism and/or responsiveness to GA1. Although our knowledge is still very fragmentary, available results suggest that cessation of growth and initiation of hardening in trees can be controlled both through the phytochrome and the GA mediated systems. Research with tree species is a tedious and slow process, but with the emerging new methods and approaches, we may expect exciting new results in the near future.     

燕麦AsSnRK2.7编码蛋白的分子特征及基因表达特异性研究

蔗糖非发酵相关的蛋白激酶2（SnRK2）通过磷酸化在植物胁迫信号转导途径中起关键作用。为发掘并利用燕麦中的 SnRK2基因,本研究基于燕麦转录组数据的注释信息,利用RT-PCR技术从燕麦品种美达中克隆了 AsSnRK2.7基因,借助生物信息学、瞬时表达及实时荧光定量RT-PCR（qRT-PCR）技术分别对该基因或其编码蛋白进行分子特征分析、亚细胞定位和表达特异性研究。结果表明, AsSnRK2.7基因包含一个1 074 bp的开放阅读框,编码357个氨基酸,预测其编码蛋白含有一个STKc_SnRK2结构域和一个PKc_like superfamily结构域,属于SnRK2蛋白激酶家族成员。AsSnRK2.7蛋白一级序列中包含多个SnRK2家族特有的重要功能区。AsSnRK2.7蛋白与水稻的SnRK2蛋白激酶相似性最高,属于Group Ⅰ（SnRK2b）亚家族。亚细胞定位结果显示,AsSnRK2.7蛋白主要定位在细胞核中。qRT-PCR结果显示, AsSnRK2.7基因为组成型表达,在根、茎、叶和穗中的最大表达量分别出现在苗期、分蘖期、抽穗期和灌浆期;此外, AsSnRK2.7基因的表达不被ABA激活,但可以积极应答PEG、盐和低温胁迫。以上结果说明, AsSnRK2.7基因可能作为一个调节因子,通过非依赖ABA途径来调节干旱、盐和低温所引发的信号传导。     

Properties of lupine proteins relevant to their nutritional performance

Composition, solubility, bound sugar content and quality, subunit composition and structure of the storage proteins of seeds ofLupinus albus are discussed. Aminoacid composition is also given for each protein, the various protein classes and the whole flour. These data allow for the characterization of the molecules of the various storage proteins and their contributions to the nutritional properties of the seed.In vitro digestibility (by mammalian endopeptidases) is reported and is less than for animal proteins. Possible causes, at the molecular level, for this behaviour and possible means to overcome these effects are examined. The relationships between the above data are considered in view of the nutritional performance of the proteins and of the genetical, agronomic and technological approaches most suited to improve the nutritional quality of lupine seeds as a protein source.     

生长素反应因子ZmARF1的表达分析及互作网络探究

以抗旱型玉米自交系郑36和弱抗旱型玉米自交系B73为试验材料,利用克隆、qRT-PCR、亚细胞定位、互作蛋白预测等手段验证ZmARF1(GRMZM2G702026)对干旱胁迫的响应模式及初步探究ZmARF1基因的互作网络。克隆及测序分析表明,该基因含有1个2 034 bp的开放阅读框,翻译677个氨基酸。蛋白分析表明,该蛋白无跨膜域,属于高亲水性蛋白,亚细胞定位于细胞核。潜在磷酸化位点分析显示,ZmARF1蛋白含有潜在的丝氨酸、苏氨酸和酪氨酸磷酸化位点数目分别为39、16、6个。复合进化树、功能域和保守motif分析表明,该基因蛋白与其他物种同源性较高,说明不同物种该基因在功能上较保守。ZmARF1属于组成型表达基因,受干旱胁迫的正向诱导,且郑36基因表达量上升幅度大于B73。预测的互作功能蛋白主要通过调节激素应答基因的表达、参与激素介导的信号等途径,来调控植物对逆境的胁迫应答和生长发育等过程。     

河南省小麦品种春化特性和光周期特性的研究

以河南省20世纪40年代至今的30个小麦大面积栽培品种为材料,采用春化特性和光周期特性离析试验、田间幼穗分化进程观察的方法,对河南省小麦品种春化特性和光周期特性进行了分类和演化分析,并利用STS标记对供试品种的春化和光周期基因进行了检测。结果表明,在河南省70年来的小麦大面积品种演化中,存在着多种春化与光周期反应类型,但春化特性的演化表现为冬性程度由强减弱再增强的变化趋势;光周期特性敏感程度表现出逐渐降低的趋势。经分子标记检测,河南省70年来大面积推广品种的春化基因主要为 vrn-A1、 vrn-B1、 vrn-D1、 Vrn-D1b和 vrn-B3,光周期基因主要为 Ppd-A1a、 Ppd-D1a,但这些基因对春化特性和光周期特性的作用效果总体上尚不能准确反映品种的冬春性和光周期特性的实际情况,在育种工作中春化特性和光周期特性的选择与鉴定仍应以表型鉴定为主。     

Effect of Nitrogen Regimes on Combining Ability Variation in Oil and Protein Contents in Cottonseed (Gossypium hirsutum L.)

Abstract

Eight parental cultivars and 56 hybrids of cotton (Gossypium hirsutum) were grown in normal and nitrogen-deficient conditions in the field to investigate the effect of nitrogen regime on the oil and protein contents and their combining ability. The mean oil and protein contents of the parental cultivars greatly varied with the nitrogen regime, which indicated their nitrogen sensitivity. The genetic variability of oil and protein contents was low in the same nitrogen regime, but was high in the comparison between the normal and nitrogen-deficient conditions. The nitrogen regime affected not only the oil and protein contents and ranking of parental cultivars, but also the combining ability. A normal nitrogen level was found to be more useful for selecting the additive type of gene action in breeding of cotton.     

Characterization of Amaranthus cruentus L. seed proteins by 2-DE and LC/MS–MS: Identification and cloning of a novel late embryogenesis-abundant protein

Amaranth is taking great attention as an important cereal crop that could fulfill food requirements for the growing population, especially in developing countries. However, the protein composition of these seeds is not well known yet. We have used the proteomics tools to characterize amaranth seed proteome. About 400 proteins spots were resolved on two-dimensional gel electrophoresis (2-DE) and protein spots were analyzed by LC-MS/MS (liquid chromatography tandem mass spectrometry). Identified proteins were related to stress and defense responses, metabolic, respiratory, and oxide-reduction processes. One abundant spot was identified as a Late Embryogenesis Abundant (LEA) protein and the gene was cloned and characterized. The AcLEA cDNA contains a 418 bp open reading frame (ORF) encoding a polypeptide of 139 amino acids. Bioinformatics analysis showed that AcLEA belongs to LEAs Group 5. Proteomics is a powerful technique that could be used even in non-sequenced organisms such as amaranth. The obtained information reveals that amaranth seed, beyond the classical seed storage proteins, contains proteins related to protection against stress. The identification of these proteins opens the door to the application of new strategies to improve the quality of amaranth production.     

The Effect of Elevated Atmospheric CO2 Concentration on Two Populus Clones Grown in a FACE System

SUMMARY

Two poplar clones, hybrid Populus deltoides Bartr. Ex Marsh X Populus nigra L. (Populus xeuramericana), clone I-214, and Populus deltoides, clone Lux, were grown from hardwood cuttings for one growing season in either ambient (360 μmol mol^?1) or elevated (560 μmol mol^?1) [CO₂] in FACE-systemrings at Rapolano Terme (Siena, Italy). Both clones I-214 and Lux exhibited a higher aboveground bio-mass, photosynthesis at light saturation and instantaneous transpiration efficiency (ITE) in CO₂-enriched air. The elevated [CO₂]-induced responses of clone I-214 included increased investment in branch and leaf biomass, and enhanced stem volume. The elevated [CO₂]-induced responses of clone Lux included an increase in the number of branches (and foliage area). Indication of photosynthetic acclimation under elevated [CO₂] was found during the early morning, but only in clone I-214. Stomatal conductance decreased under elevated [CO₂] particularly in clone Lux. Clone differences in response to elevated [CO₂] should be taken in account when planning future poplar plantations in forecast warmer and drier Mediterranean sites.     

Inductive and noninductive conditions on in vitro tuberisation and microtuber dormancy in potato (Solanum tuberosum subspeciestuberosum and subspeciesandigena)

Summary The effect of growth conditions (medium and photoperiod) on in vitro tuberisation and microtuber dormancy of the cv. Désirée (Solanum tuberosum subspeciestuberosum) and Imilla Negra (Solanum tuberosum subspeciesandigena) was evaluated. The short photoperiod and presence of CCC in the medium reduced the dry matter of plants as well as the size of microtubers. The two cultivars showed a difference, in favour of Désirée, in the percentage of plants having more than one tuber and in the average time of sprouting after storage. The average time of sprouting was more rapidly obtained under long days and in a medium without CCC. The CCC and short days caused the same dormancy conditions and the same K⁺ quantity in the microtubers. The microtubers mineral composition is involved in the dormancy status.     

Pigeonpea Nutrition and Its Improvement

Abstract

Pigeonpea (Cajanus cajan [L.] Millsp.), known by several vernacular and trade names such as red gram, tuar, Angola pea, Congo pea, yellow dhal and oil dhal, is one of the major grain legume crops of the tropics and sub-tropics. It is a favorite crop of small holder dryland farmers because it can grow well under subsistence level of agriculture and provides nutritive food, fodder, and fuel wood. It also improves soil by fixing atmospheric nitrogen. India by far is the largest pigeonpea producer where it is consumed as decorticated split peas, popularly called as ‘dhal’ In other countries, its consumption as whole dry seed and green vegetable is popular. Its foliage is used as fodder and milling by-products form an excellent feed for domestic animals. Pigeonpea seeds contain about 20-22% protein and appreciable amounts of essential amino acids and minerals. Dehulling and boiling treatments of seeds get rid of the most antinutritional factors such as tannins and enzyme inhibitors. Seed storage causes considerable losses in the quality of this legume. The seed protein of pigeonpea has been successfully enhanced by breeding from 20-22% to 28-30%. Such lines also agronomically performed well and have acceptable seed size and color. The high-protein lines were found nutritionally superior to the cultivars because they would provide more quantities of utilizable protein and sulfur-containing amino acids.     

Effect and interaction of crop management factors on the glycoalkaloid concentration of potato tubers

Summary Potato tuber glycoalkaloid content was measured in response to nitrogen fertilizer rate, storage temperature, length of storage period and cultivar. Cvs Gemchip, Norchip and Russet Burbank were grown with applied nitrogen fertilizer rates of 0, 168 or 336 kg/ha and then stored at either 4.4 or 10°C. Total glycoalkaloid content was determined one month before harvest, at harvest, after three months of storage and after nine months of storage. Higher rates of nitrogen, higher storage temperature and a period of storage all resulted in significantly (P<0.05) higher concentration of glycoalkaloids. The cv Norchip had higher glycoalkaloids than cvs Gemchip or Russet Burbank. Only the storage period had more influence than the environment (difference between years). Significant (P<0.05) two-way interactions were detected for year x cultivar, year x nitrogen, storage period x cultivar and nitrogen x cultivar. Most interactions were due to the unique responses of cultivars.     

High temperature and low solar radiation during ripening differentially affect the composition of milky-white grains in rice (Oryza sativa L.)

ABSTRACT

Temperatures and solar radiation during ripening critically affect grain appearance in rice (Oryza sativa L.). Climatic factors to induce chalky grains were analyzed under the experimental conditions of high-temperature and shading treatment and also under the ambient condition in a high-temperature-prone region of Japan. The frequency of white-back (WB) and basal-white (BW) grains correlated with temperature and solar radiation, whereas that of milky-white (MW) grains was not correlated, suggesting that complicated climatic factors are involved in the formation of MW grains. Further investigation was carried out to identify the parameters that distinguish perfect and MW grains grown in high-temperature versus those grown in low-solar-radiation conditions. As reported previously, the chalk phenotypes in the transverse section of the MW grains were quite different between environments: oval-shaped chalk for MW grains grown in low-solar-radiation condition and center chalk for MW grains grown in high-temperature condition. Grain hardness and amylopectin chain-length distribution did not explain the difference in MW grains between environments. MW grains subjected to high temperatures had a lower protein content without a consistent reduction in the single-grain weight, whereas those from the low-solar-radiation condition had a lower amylose content with a consistent reduction in the single-grain weight, when compared with perfect grains that developed in either environmental condition. Overall, our results suggest that MW grains are formed through different physiological mechanisms with altered starch and protein synthesis under high-temperature and low-solar-radiation conditions.

Abbreviations: BW: basal-white; DAH: days after heading; DP: degree of polymerization; MW; milky-white WB: white-back     

Influence of growth conditions on the value of crisphead lettuce

Crisphead lettuce (Lactuca sativa L. varcapitata cvs.Marius andSaladin) were grown with a nitrogen supply from 50 to 200 kg N/hectare. Heads were stored for one or two weeks at 1 °C in cold storage or ice bank cooling. Samples were taken for measurement of dry matter, sugars, vitamin C and nitrate. The content of dry matter, sugars (glucose, fructose) and vitamin C decreased with increasing level of nitrogen, and the content of nitrate increased. Except for nitrate the contents of the other quality attributes decreased at all nitrogen supply levels during storage. No differences were found between the storage systems, and beside fructose no significant differences were found between the two cultivars. The content of dry matter, vitamin C, and nitrate decreased from the outer to the inner head fraction, while the content of sugars increased. Trimming decreased the content of dry matter, vitamin C and nitrate and increased the content of sugars. To obtain heads from storage with a relatively high content of dry matter, sugars and vitamin C, and a relatively low content of nitrate the nitrogen supply must be as low as possible. Except for nitrate where no distinct results were found in this experiment it must also be recommended to store the heads as short time as possible. Possibly the cv.Saladin has some advantage quality attributes after storage compared with the cv.Marius.     

Flower Development and Photoperiodic Control of Flowering in Rice

Floral transition,which is referred to as a plant’s transition from vegetative stage to reproductive stage,is considered to be a critical developmental switch in higher plants,for a timely flowering is a major factor of reproductive success.Endogenous and environmental cues,such as photoperiod,light quality,plant hormones concentrations and temperature,provide information to the plants whether the environment is favorable for flowering.These cues promote,or prevent,flowering through a complex genetic network,mediated by a careful orchestration of temporal and spatial gene expression.One of such cues is photoperiod.Rice(Oryza sativa L.) serves as a powerful model species for the understanding of flowering in higher plants,including flower development and photoperiodic control of flowering.In this review,we overviewed and discussed the flower development and its model.We also overviewed the photoperiodic pathways in rice flowering control,and summarized the pathways at molecular level.