andZea Mays Research Articles

Determination of polyphenols, antioxidant activity, and antimicrobial properties of Zhourat using different extraction conditions

Zhourat is an herbal infusion popular in the Middle East consisting of a mixture of different plants. The aim of this study was to (1) to determine the best conditions to extract phenolic compounds from twelve plants and their combination (Rosa damascena (Wared Joury, Zer Wared), Viola odorata L., Matricaria chamomilla L., Althaaea officinalis Linn., Melissa officinalis, Elaeagnus angustifolia L., Foeniculum vulgare L., Pimpinella anisum L., Saccharum officinarum L., Prunus dulcis, andZea mays L.), and (2) to elucidate their bioactive potential (antioxidant and antimicrobial capacity). Different conditions were used for the extraction and the subsequent analysis was performed. Results showed that optimal extraction conditions vary greatly between different kind of plants. A mixture of 50% water/50% ethanol at 40°C appeared to be optimal to extract the antioxidant and antimicrobial compounds for the samples tested. The total phenolic content (TPC) ranged from 0.2 mg GAE/g and 11.4 mg GAE/g. Zer Wared and Wared extracts at 40 ˚C showed the highest free radical scavenging activity. For TPC and anti-radical properties, Zhourat blend extracts did not show any additional effect over individual plants, and results fell in mid-range. As for the antimicrobial effect, antibacterial properties varied among the different plants as well. No synergistic effects appeared for the Zhourat mixture as a whole; neither antimicrobial nor antioxidant tests showed added value in mixing twelve plants. Wared and Zer Wared seem to have the best antioxidant and antimicrobial properties, followed by the Zhourat mixture. The results suggested that the most available herbal infusions in Lebanon should better be consumed on their own, rather than in a Zhourat Mixture. The combination of herbal ingredients in Zhourat mixture mertits further inbestigation.

Identification and Characterization ofWheat Streak Mosaic VirusIsolates in Wheat-Growing Areas in Brazil

Wheat streak mosaic virus(WSMV—Potyviridae,Tritimovirus), transmitted by the eriophyid miteAceria tosichellaKeifer (Acari:Eriophyidae), was considered a quarantine pest in South America. Since the first report of virus in Argentina, the vector has been found in Argentina, Uruguay and Brazil. The objective of this work was to determine the occurrence of WSMV in Brazil and characterize isolates from wheat-growing areas. Between 2009 and 2011, a total of 40 samples collected in wheat (Triticum aestivum) growing areas, where the presence of the mite was previously related, were tested by RT-PCR for virus detection. Six isolates of WSMV were obtained and characterized by sequencing. Two of them had their host range determined. The Brazilian WSMV isolates clustered in clade D are closely related to the Argentine isolate Arg2 (FJ348359). As expected, isolates were unable to infect dicotyledons plants. They caused mosaic inTriticum aestivum,Hordeum vulgare,Secale cereale, ×Triticosecale, andZea mays, and they were also able to infectAvena sativa. The presence of WSMV in wheat-growing areas of the Brazilian state Rio Grande do Sul was confirmed, possibly having been introduced from a common source and/or direct vector bearing virus migration from Argentina.

Molecular diversity amongSaccharum, Erianthus, Sorghum, Zea and their hybrids

The phylogenetic relationship of sugarcane (Saccharum officinarum) with three other related genera viz.,Erianthus, Zea andSorghum and their 12 intergeneric hybrids was studied using 250 RAPD markers.S.officinarum andErianthus, though belonging to the same sub tribe, showed strong molecular differentiation between them. The phenogram based on these markers showed thatErianthus andSorghum are almost equidistantly placed fromSaccharum officinarum while maize was found to be the most outlying genus in relation toS.officinarum. The 12 hybrids of sugarcane (S. officinarum) withErianthus spp.,Sorghum bicolor andZea mays were found to be closer to theirSaccharum parent than to the respective related genera. This is possibly because of the higher chromosome contribution ofSaccharum compared to the related genera in the hybrids.

Effect of elevated carbon dioxide concentration at night on the growth and gas exchange of selected C4 species

Biomass of certain C4 species is increased when plants are grown at elevated CO2 concentrations. Experiments using four C4 species (Amaranthus retroflexus L., Amaranthus hypochondriacus L., Sorghum bicolor (L.) Moench and Zea mays L.) exposed both day and night from sowing to carbon dioxide concentrations of 370 (ambient) or 700 µmol mol-1 (elevated) or to 370 µmol mol-1 during the day and 700 µmol mol-1 at night, determined whether any biomass increase at elevated CO2 concentrations was related to a reduction in the night-time rate of CO2 efflux at high night-time CO2 concentrations. Of the four species tested, only A. retroflexus significantly increased both CO2 assimilation (+13%) and plant biomass (+21%) at continuous elevated relative to continuous ambient concentrations of CO2. This increase was not associated with improvement in leaf water potential during dark or light periods. In contrast, high CO2 only during the night significantly reduced plant biomass compared to the 24 h ambient CO2 treatment for both A. retroflexus and Z. mays. This indicates that the observed increase in biomass at elevated CO2 for A. retroflexus was not caused by a reduction of carbon loss at night (i.e. increased carbon conservation), but rather a direct stimulation of daytime CO2 assimilation, independent of any improvement in leaf water potential.

BRANCHED SILKLESSmediates the transition from spikelet to floral meristem duringZea maysear development

Summary The molecular and genetic control of inflorescence and flower development has been studied in great detail in model dicotyledonous plants such as Arabidopsis and Antirrhinum . In contrast, little is known about these important developmental steps in monocotyledonous species. Here we report the analysis of the Zea mays mutant branched silkless1–2 (bd1–2) , allelic to bd1 , which we have used as a tool to study the transition from spikelet to floret development in maize. Floret development is blocked in the female inflorescence (the ear) of bd1–2 plants, whereas florets develop almost normally in the male inflorescence (the tassel). Detailed phenotypic analyses indicate that in bd1–2 mutants ear inflorescence formation initiates normally, however, the spikelet meristems do not proceed to form floret meristems. The ear spikelets, at anthesis, contain various numbers of spikelet‐like meristems and glume‐like structures. Furthermore, growth of branches from the base of the ear is often observed. Expression analyses show that the floral‐specific MADS box genes Zea mays AGAMOUS1 ( ZAG1 ), ZAG2 and Zea mays MADS 2 ( ZMM2 ) are not expressed in ear florets in bd1–2 mutants, whereas their expression in tassel florets is similar to that of wild type. Taken together, these data indicate that the development from spikelet to floret meristem is differentially controlled in the ear and tassel in the monoecious grass species Zea mays , and that BRANCHED SILKLESS plays an important role in regulating the transition from spikelet meristem to floral meristem during the development of the female inflorescence of maize.

Atomic force microscopy of pollen grains, cellulose microfibrils, and protoplasts

Atomic force microscopy (AFM) holds unique prospects for biological microscopy, such as nanometer resolution and the possibility of measuring samples in (physiological) solutions. This article reports the results of an examination of various types of plant material with the AFM. AFM images of the surface of pollen grains ofKalanchoe blossfeldiana andZea mays were compared with field emission scanning electron microscope (FESEM) images. AFM reached the same resolutions as FESEM but did not provide an overall view of the pollen grains. Using AFM in torsion mode, however, it was possible to reveal differences in friction forces of the surface of the pollen grains. Cellulose microfibrils in the cell wall of root hairs ofRaphanus sativus andZ. mays were imaged using AFM and transmission electron microscopy (TEM). Imaging was performed on specimens from which the wall matrix had been extracted. The cell wall texture of the root hairs was depicted clearly with AFM and was similar to the texture known from TEM. It was not possible to resolve substructures in a single microfibril. Because the scanning tip damaged the fragile cells, it was not possible to obtain images of living protoplasts ofZ. mays, but images of fixed and dried protoplasts are shown. We demonstrate that AFM of plant cells reaches resolutions as obtained with FESEM and TEM, but obstacles still have to be overcome before imaging of living protoplasts in physiological conditions can be realized.

Light activation of enzymes in relation to leaf age inVigna unguiculata (L.) Walp andZea mays L.

The effects of light-dark transition and aplastidic condition by the photobleaching herbicide, 3-amino-1,2,4-triazole, on the activities of enzymes likein vivo nitrate reductase, peroxidase, polyphenol oxidase and catalase were studied in leaves of different ages of 30-day old plants ofVigna unguiculata andZea mays. The activity of nitrate reductase was found to be higher in young leaves and showed a gradual decline at the time of maturity and senescence. In amitrole-bleached young leaves,in vivo nitrate reductase activity was significantly reduced. Although peroxidase is a light-activated enzyme, the enzyme was more active only in fully mature and senescing leaves ofVigna unguiculata. InZea mays, peroxidase activity was more in mature leaves compared to senescent leaves. Interesting feature of this enzyme was that its activity increased upon dark treatment inVigna unguiculata. A similar trend was also observed in polyphenol oxidase activity in mature and senescent leaves ofVigna unguiculata andZea mays. Foliar spray of amitrole increased peroxidase and polyphenol oxidase activities in the young leaves ofZea mays andVigna unquiculata. The results are discussed in relation to age of leaves and the presence or absence of leaf plastids.

Molecular characterization of the diurnal/circadian expression of the chlorophyll a/b-binding proteins in leaves of tomato and other dicotyledonous and monocotyledonous plant species

Diurnal oscillations of steady-state mRNA levels encoding the chlorophyll a/b-binding proteins were monitored inLycopersicon esculentum, Glycine max, Phaseolus vulgaris, P. aureus, P. coccineus, Pisum sativum, Sinapis alba, Hordeum vulgare, Triticum aestivum andZea mays. In these plant speciescab mRNA accumulation increases and decreases periodically indicating i) that the expression of the genes for chlorophyll a/b-binding proteins (cab genes) is controlled by a circadian rhythm, and ii) that the rhythm is widely distributed among monocotyledonous and dicotyledonous plant species. A detailed characterization of the pattern ofcab mRNA expression in tomato leaves shows that the amplitude of the oscillation is dependent on i) the developmental stage of the leaves, ii) the circadian phase and duration of light and iii) the circadian phase and duration of darkness. In addition to the chlorophyll a/b-binding proteins, genes coding for other cellular functions were examined for cyclic variations of their mRNA levels. The analysis includes genes involved in i) carbon metabolism (e.g. phosphoenolpyruvate carboxylase, pyruvate orthophosphate dikinase, alpha amylase, fructose-1,6-bisphosphate aldolase, triosephosphate isomerase), ii) photosynthesis (large and small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, QB-binding protein, reaction-center protein of photosystem I) and iii) other physiological or morphological reactions (e.g. ubiquitin, actin). However, no periodic fluctuation pattern was detected for the mRNA levels of these genes in tomato and maize leaves.

Chalcone synthase genes in plants: A tool to study evolutionary relationships

Chalcone synthase (CHS) is the key enzyme of the anthocyanin biosynthesis pathway in plants. cDNAs specific for CHS have been isolated and sequenced for the following species:Hordeum vulgare (1477 bp),Magnolia liliiflora (1359 bp),Petunia hybrida (1335 bp),Ranunculus acer (1334 bp and 1358 bp), andZea mays (1461 bp). Comparison of the coding regions of these CHS cDNA sequences including the sequences ofAntirrhinum majus (Sommer and Saedler 1986) andPetroselinum hortense (Reimold et al. 1983) reveals a similarity higher than 66% at the nucleotide and higher than 80% at the amino acid level. The CHS transcript is G/C rich in monocotyledons (65.7%–69.3%), but not in dicotyledons (45.5%–53.9%). The monocotyledonous plants show a strong codon bias preferring codons with a G or C in the third position. A phylogenetic tree was constructed on the basis of nucleotide sequence comparison; it is evident that the branching order ofRanunculus acer andPetroselinum hortense is changed as compared to the morphological order. Splitting of the CHS coding region into two parts represented by the common position of one intron seems to indicate that the first exon ofPetroselinum hortense evolved in a way different from the same exon of all other species.

Mesocotyl growth of etiolated seedlings ofAvena sativa andZea mays in relation to light and diffusible auxin

Diffusible auxin levels were measured in coleoptiles and mesocotyls of dark-grown seedlings ofavena sativa (cv. Spear) andZea mays (cv. Golden Cross Bantam) using theAvena curvature bioassay. The coleoptile tip was confirmed as the major auxin source in etiolated seedlings. Auxin levels were found to decrease basipetally in sequent sections of theAvena coleoptile but not to decrease in apical sections of increasing length. An inhibitor capable of inducing positive curvatures ofAvena test coleoptiles was discovered in diffusates from the mesocotyls of oat and corn seedlings. The amount of this inhibitor was correlated with the cessation of mesocotyl growth of oat seedlings grown in darkness, and with the inhibition of mesocotyl growth of corn seedlings exposed to red light.

Changes in the frequency of two types of nuclear body during the interphase of meristematic plant cells

After impregnating root meristems with silver nitrate two types of small (< 1 Μm diameter) body can be seen in the nuclei. These have been termed “dense body” (DB) and “nucleolus-associated body” (NAB). The number of these bodies within a nucleus varies from species to species, but in general DBs are relatively numerous and lie in the nucleoplasm, while the NAB is usually solitary and lies on the surface of the nucleolus. Using nuclear volume as an indicator of the age of the nucleus since mitosis, the numbers of DBs and NABs were related to the nuclear growth cycle. In the meristem ofPisum sativum andZea mays DBs are characteristically present in early interphase; in some regions they persist in the nucleoplasm until the next mitosis, in other regions they disappear during interphase. DBs are probably pieces of the pellicle of ribonucleoprotein that coats mitotic chromosomes which have not coalesced (as does the remainder of the pellicle) to form the nucleolus at the start of interphase. NABs grow out from the nucleolar surface during the later stages of interphase. At the end of interphase there is on average 1 NAB per nucleolus.

Asiatic Clam (Corbicula manilensis) and Other Foods Used by Waterfowl in the James River, Virginia

Corbicula manilensis was found in the gizzards of 24 ducks of 5 species taken from the James River, Virginia, between 1973 and 1976. Percent average volume in these species ranged from trace to 6%. This is the first known occurrence of this exotic clam in the food of duck in Chesapeake Bay. A total of 135 other food items was identified from the 116 gizzards of 9 species that were examined. Food that predominated includedCyperus spp.,Leersia oryzoides, Polygonum spp., andZea mays. The great diversity of food consumed in this fresh tidal section of the James River indicates the high value of these wetlands to waterfowl. *** DIRECT SUPPORT *** A01BY015 00008

Metabolic studies inSorghum vulgare Pers. andZea mays L. during seedling growth

Protein content declined in the endosperm while an increase was noticed in root and shoot of young seedlings ofS. vulgare andZ. mays. Seedlings of both plants in light had a larger pool of α-alanine, leucine-phenylalanine, glutamic acid, aspartic acid, valine, asparagine, serine-glycine and γ-aminobutyric acid than other amino acids. Tyrosine, proline, threonine and tryptophan which were recorded in light could not be detected in dark. Asparagine and glutamine increased with the seedling growth in most of the samples studied. Phosphoenolpyruvate and pyruvic acid constituted the bulk of keto acid pool while succinate, malate and citrate of organic acid pool. Protein content and citric acid level were found higher in light than in dark grown seedlings of both plants. The higher level of PEP and pyruvic acid in young shoots in light and their sharp decline at advanced stages may be due to a shift from C3 to C4 metabolism.

Cochliobolus nodulosus . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Cochliobolus nodulosus . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Eleusine coracana [Eleusine indica] and E . indica . Also on Echinochloa frumentacea, Panicum miliaceum, Pennisetum typhoideum Saccharum spp., Sorghum spp. and Zea mays . DISEASE: Seedling blight, foot rot and leaf blight of finger millet ( Eleusine coracana [Eleusine indica] and E. indica ). Elliptical to long rectangular spots form on the leaves, becoming coalescent, straw coloured with narrow red-brown margins. Spikes are infected and may collapse; grain does not form or is undeveloped. Systemic infection has been described for E . indica (37: 78). Many infected plants die in the seedling stage but others show the stunting caused by this type of infection. When older plants were inoculated systemic infection occurred in the new growth only; such plants may show some tillers to be infected and stunted whilst others are normal and healthy. GEOGRAPHICAL DISTRIBUTION: Widespread in E. and S. Africa, also Nigeria and Sierra Leone, in India, Formosa, Malaysia (Sarawak), Papua New Guinea, Philippines, Sri Lanka and USA (Ga, Md, Miss., S. Carol. and Va) (CMI Map 454, ed. 1, 1969). TRANSMISSION: Seed-borne.

The organization of chloroplast membranes ofVicia faba andZea mays after processing to retain chlorophyll and hydrophobic lipids in the chloroplasts

Chloroplasts, bothin situ and isolated, were dehydrated at low temperatures to avoid chlorophyll extraction. These chloroplasts were fixed with glutaraldehyde only or with glutaraldehyde followed by osmium. Chloroplasts dehydrated at low temperatures have narrower fret membranes, but the same dimensions of the partitions as chloroplasts dehydrated by standard techniques. However, the two membranes forming the partition are separated by an electron transparent region or A-component in low temperature dehydrated chloroplasts post-fixed with osmium. With glutaraldehyde only, the A-component appears as a thin discontinuous dark line. The results indicate that the A-component is a structural component of the partition and supports the hypothesis that chlorophyll and the hydrophibic lipids are localized there.

Pseudomonas rubrlineans . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Pseudomonas rubrlineans . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Saccharum officinarum . Also found infecting Paspalum nutans, P. paniculatum (35: 750) and Zea mays (37: 205). Produces symptoms on Sorghum spp. when artificially inoculated. DISEASE: Red stripe disease of sugarcane. Two types of symptom occur: leaf stripe , in which long, narrow, sharply delineated, dark red stripes are observed and top rot , which may occur with or without leaf stripe symptoms. The latter phase of the disease causes much greater economic losses. GEOGRAPHICAL DISTRIBUTION: Widely dispersed throughout the world and reported from many sugarcane areas (CMI Map 39, ed. 3, 1966). TRANSMISSION: The pathogen is spread by wind and rain, especially in warm humid weather. Cottrell-Dormer showed that liquid exuded from stomata and hydathodes in such weather may contain large numbers of bacteria. Penetration is through stomata or wounds. The disease can be introduced into new areas with infected setts.

Aspergillus flavus . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Aspergillus flavus . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The fungus normally occurs as a saprophyte in soil and on many kinds of decaying organic matter causing no economic damage or disease. However, on occasion it may act as a spoilage organism of stored seeds and grains, including Arachis hypogaea (groundnut), Bertholletia excelsa (Brazil nut), Cicer arietinum, Cucurbita pepo, Elaeis guineensis, Oryza sativa, Phaseolus vulgaris, Sorghum spp., Theobroma cacao, Triticum spp., Vigna sinensis [Vigna unguiculata] and Zea mays (Herb. IMI), or become pathogenic to seedling plants as well as to man, cattle, birds and insects. DISEASES: On man and animals : The infection is most often pulmonary as in pigeon and turkey (Ainsworth &amp; Austwick; RMVM 2, 1721) and captive wild birds (Ainsworth &amp; Rewell; RMVM 1, 2090) or general as in broiler chickens (Stock, Avian Dis . 5: 89-93, 1961). Other types include bronchial infections, endocarditis and infections of the ear (Wolf; RMVM 1, 1095), brain, skin, nail, eye (Fazakaz; RMVM 4, 1084) and orbit in man and infection of the bovine placenta (see Austwick, 1965, p. 101). Aspergillus flavus is regarded as an important pathogen of insects (Austwick, 1965, p. 101-102). On plants : A limited amount of invasion of unblemished, intact, immature or mature groundnut pods has been recorded in the southern U.S.A. in the field. Diener et al. (1965) found that the invasion of overmature kernels and shells before harvest was reduced when rainfall was abundant and well distributed and when temperatures were moderate. It has been found to attack germinated groundnuts in the seed bed, particularly after injury to the seed coat or cotyledon (Clinton, 1960) and has also been reported highly pathogenic to cotton seedlings (37: 662). It has been isolated from rhizospheres of Viciafaba in Egypt (Herb.IMI). Aflatoxin production . Some strains when growing on groundnuts produce a toxin, afiatoxin. Toxic groundnuts induce disease in turkeys and ducklings (RMVM 4, 908) and Lancaster et al. (1961) demonstrated carcinogenic effects on rats fed on a diet containing 20% toxic groundnut meal. Aflatoxin has a large literature, see Austwick (in Raper &amp; Fennell 1965, p. 106-109); RMVM: numerous papers, books and symposiums particularly, RMVM 4, 1731; Austwick &amp; Ayerst, RMVM 4, 1732; 5, 1618; Wogan, 1965. GEOGRAPHICAL DISTRIBUTION: World-wide, particularly in tropical soils.

The behavior of nuclei in germinating pollen grains of wheat, rice and maize

1. Three species of Gramineae were used for obeservations on the behavior of the tube nucleus and sperm nuclei in germinating pollen grains ofTriticum aestivum, Oryza officinalis andZea mays.

The effect of high concentrations of heavy water on root development inPisum sativum andZea mays

The early effects of D/sub 2/O (50 to 90%) on pea and corn seedlings were examined. When the roots of intact pea seedlings are immersed in high concentrations (80 to 90%) of D/sub 2/O for 24 hr, no increase in root length occurs. Immediately above the root apex, swellings occur as a result of widening of cortical cells and parenchymatous components of the stele, and disturbances of the vascular pattern are also observed. In roots which are grown out after treatment, no laterals are found along that portion corresponding to the region of elongation at time of treatment. Their development is blocked at the primordial level. Growth rates of roots after 24-hr treatment are proportionai to the D/sub 2/O concentrations applied. The mitotic index of pea roots approaches zero within eight hr after immersion in 70 to 90% D/sub 2/O. At concentrations lower than 90%, mitoses recommence while the roots are still in heavy water. The mitotic cycle appears to be partially phased as a result of the treatment. In corn roots, two mitotic blocks occur during the first hour of D/ sub 2/O exposure; the first prevents the flow of cells into prophase, the second occurs at the endmore » of metaphase. The preprophase block is released after 1/4 hr and the renewed flow of cells added to the cells held in metaphase increases the mitotic index above that of the controls. After the first hour of treatment a general suppression of mitotic activity sets in. In peas the mitotic index drops continuously and more rapidly than in corn. Both peas and corn can adapt to growth in 80% D/sub 2/O. Whereas all pea roots resume growth after the first 8 hr, those of corn require 48 hr before 1/3 of the population shows renewed mitotic activity. Thus, the monocot in most ways is much more sensitive to high concentrations of heavy water than the dicot. One exception may be in relation to anatomical changes brought about by this treatment, since peas showed much greater disturbances in vascularization. (BBB)« less