番茄果实成熟软化过程中细胞壁作用机制研究进展

番茄是研究果实成熟的重要模式作物,细胞壁结构和成分的改变是造成果实成熟变软的重要因素,综述了果实成熟过程中细胞壁各种相关基因、酶和转录因子的功能和研究进展,旨在构建番茄果实成熟软化中的细胞壁作用机制相关调控网络,为增强果实耐贮性方面的相关研究提供参考.     

果实成熟软化机理分子生物学的研究进展

果实成熟软化是一个复杂的发育调控过程,其间经历了一系列生理生化变化,同时概述了果实成熟软化过程中相关酶及乙烯等因素分子生物学方面的研究进展.     

微藻油脂合成与调控的生化及基因工程研究进展

微藻可作为一种新型的生物柴油原料。对微藻油脂积累和代谢调控的了解有助于利用微藻生产生物柴油。本研究综述了生化工程及基因工程对微藻油脂合成与调控的研究进展,包括营养控制、光照、温度等对微藻油脂积累的影响;脂肪酸、三酰甘油合成过程中一些关键酶基因及转录因子的遗传操作在微藻油脂合成和积累过程中的作用等。氮营养缺乏是生化工程中最有效的提高微藻含油量的方法;参与脂肪酸、三酰甘油合成过程中的关键酶,如乙酰辅酶A羧化酶、甘油-3-磷酸脱氢酶、二脂酰甘油酰基转移酶一些关键酶基因及转录因子Dof4、bHLH的遗传操作都能大幅提高微藻油脂含量。对微藻油脂代谢的研究前景做了进一步的展望。     

果实成熟及品质调控遗传研究进展

果实的成熟涉及许多生物化学变化过程,主要包括香气、糖的产生以及果实软化等,这与果实在成熟过程中所发生的一系列代谢路径密不可分。因此,研究并了解果实成熟过程及品质调控遗传学机理,对于果实品质改良具有重大意义。本综述将结合近年来国内外果实成熟及品质改良遗传研究现状,对果实成熟变化遗传分析研究中的代谢路径、果实品质改良遗传规律、品质QTL等进行综述,旨在为果树品质育种研究提供技术参考。     

华中农业大学在番茄红素生物合成代谢研究上取得突破

<正>番茄红素是植物中所含的一种天然色素,主要存在于番茄等成熟果实中,具有极强的抗氧化功能,可清除人体内自由基。早在上世纪60年代,研究人员就针对番茄果实中番茄红素的合成代谢展开了系统而深入的研究,鉴定出番茄果实中番茄红素的生物合成和代谢途径及其限速酶,但对番茄红素生物合成和代谢的调控机制的研究一直都没有重大进展,提升番茄果实番茄红素含量的研究进展也十分缓慢。     

转录因子对果实发育成熟及品质形成调控研究进展

水果在人们日常饮食中占有十分重要的地位。果实的发育、成熟及品质形成一直是研究的热点。果实的发育、成熟及品质形成是众多转录因子综合调控的结果。转录因子对果实发育、成熟及品质形成的调控的综述有利于全面了解果实品质形成及调控的基本规律,为果实品质遗传改良提供一定的理论依据。     

哺乳动物卵母细胞成熟及调节机制

哺乳动物卵母细胞的成熟是一个复杂的生理生化过程,包括核成熟和胞质成熟。对卵母细胞研究发现,卵母细胞成熟后表现出一些特征性变化,可作为判断卵母细胞成熟的标志。进一步研究表明,卵母细胞的成熟过程受许多生化因子的调节。     

SPL调控因子在植物生长调控的研究进展

SPL(SQUAMOSA promoter-binding protein-like)是植物特有的转录因子,它参与了植物叶、花、果实的发育、发育阶段转变、花青素的合成以及胁迫应答等调控过程。SPL转录因子家族成员均含有高度保守的SBP结构域,可以特异性结合所调控基因启动子的顺式作用元件,还可与其它调控蛋白相互作用,共同调控相关基因的表达。另外,SPL在转录后水平还受miRNA156/miRNA157的负调控。本研究从SPL调控因子在植物形态建成、次生代谢、生理胁迫中的表达调控研究进展方面进行综述。     

外源硒对植物抗盐性的影响研究进展

硒作为营养元素,能够参与调控植物抗盐的生理生化代谢过程。本文就硒对植物生长发育的影响、吸收转运及提高植物抗盐性的作用机制3个方面作了总结,并对下一步的研究和应用进行了展望,以期为硒调控植物抗盐的生理生化代谢过程提供理论依据。     

温度对植物花青素苷合成影响研究进展

为了探明温度对植物花色呈色的影响,归纳了温度在植物花青素苷合成过程中的重要作用,总结了温度通过多种途径影响花青素苷的合成,分析了温度对植物花青素苷生理代谢、稳定性及关键色素酶活性的影响。认为温度在花青素苷的合成途径中以对关键色素酶活性的影响最大,指出花青素苷合成过程受多重因子影响,要探明植物呈色机制还应综合大量单因子及多因子的研究。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Variation in forage grasses as hosts of the root-knot nematode Meloidogyne naasi (Franklin) and selection for resistance in ryegrass

Summary Reactions of 13 grasses to Meloidogyne naasi varied with species; ryegrasses, fescues and their hybrids were generally susceptible and cocksfoot and timothy resistant. Marked variation in host resistance levels occurred between genotypes within cultivars.Selection of single plants, followed by tests on replicate tillers, identified resistant and susceptible genotypes in both Italian and perennial ryegrass cultivars. Resistant plants had few nematode-induced galls and fewer females and eggs than susceptibles. There was more or less continuous variation, with many genotypes intermediate between extremes of resistance and susceptibility. Selected resistant and susceptible genotypes are of use in assessing variation in nematode populations and as controls for breeding and selection programmes.     

Current and future strategies in breeding lentil for resistance to biotic and abiotic stresses

Lentil production is limited by lack of moisture and unfavorable temperatures throughout its distribution. Waterlogging and salinity are only locally important. Progress has been made in breeding for tolerance to drought through selection for an appropriate phenology and increased water use efficiency and in breeding for winter hardiness through selection for cold tolerance.The diseases rust, vascular wilt, and Ascochyta blight, caused by Uromyces viciae-fabae, Fusarium oxysporum f. sp. lentis, and Ascochyta fabae f. sp. lentis, respectively, are the key fungal pathogens of lentil. Cultivars with resistance to rust and Ascochyta blight have been released in several countries and resistant sources to vascular wilt are being exploited. Sources of resistance to several other fungal and viral diseases of regional importance are known. In contrast, although the pea leaf weevil (Sitona spp.) and the parasitic weed broomrape (Orobanche spp.), and to a lesser extent the cyst nematode (Heterodera ciceri), are significant yield reducers of lentil, no sources of resistance to these biotic stresses have been found. Directions for future research in lentil on both biotic and abiotic stresses are discussed.     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...