The association of chloroplast peripheral reticulum with low photorespiration rates in a photorespiring plant species

Summary A peripheral reticulum occurs in mesophyll chloroplasts of the pentose cycle plantDactylis glomerata L. (orchardgrass). This structural feature was previously thought to occur primarily in the chloroplasts of tropical grasses and other species utilizing the C₄-dicarboxylic-acid photosynthesis pathway. Since the peripheral reticulum is seen in a selection ofD. glomerata which has a low rate of photorespiration, but not in a selection which has a high rate of photorespiration (Carlsonet al., 1971), photorespiratory rates may be dependent in part on the presence or absence of a chloroplast peripheral reticulum.Cooperative investigations of the University of Florida and the Crops Research Division, Agricultural Research Service, U.S. Department of Agriculture. Trade names are mentioned for clarity and do not imply endorsement of products by the U. S. Department of Agriculture. Journal Series No. 3813 of the Florida Agricultural Experiment Station.     

In-vitro induction of vegetative buds by benz(a)anthracene in tobacco callus

Summary Benz(a)anthracene induced vegetative buds on callus derived from stem tissue of haploid plants of Nicotiana tabacum a response similar to that obtained by a combination of kinetin and IAA.This study was carried out under Contract No. 12-14-100-10278 (5) with the Agricultural Research Service, U.S. Department of Agriculture, administered by the Eastern Utilization Research and Development Division, Philadelphia.     

Lipoxidase in early growth of wheat

Lipoxidase activity in etiolated wheat seedlings grown for 3.5days was localized primarily in the coleoptile and first leafof the seedling with moderate activity in the germinated seedand root. After 7 days growth, the distribution of lipoxidasewithin the plant did not change markedly while the total activitydecreased. The dormant wheat seed exhibited 2 major and 2 minor bands oflipoxidase activity on polyacrylamide gel zymograms. After germination,there was a marked change in the relative intensities of the4 lipoxidase bands depending on the part of the seedling assayed. ¹ Supported in part by funds from the Agricultural ResearchService, U. S. Department of Agriculture Grant No. 12-14-100-7654(74)administered by the Western Utilization Research and DevelopmentDivision, Albany, California. Published with the approval ofthe Director of the Wisconsin Agricultural Experiment Station. ² Present address: U. S. Department of Agriculture, NorthernGrain Insects Research Laboratory, Brookings, South Dakota 57006,U.S.A. ³ Present address: Institute of Experimental Phytopathologyand Entomology, Ivanka Pri Dunaji, Czechoslovakia.     

The inhibition of seedling growth by crop residues in soil inoculated withPenicillium urticae Bainer

Summary Laboratory experiments were conducted to determine the effects of crop residues, without and withPenicillium urticae Bainer inoculation, on growth of wheat seedlings in soil. Fifty grams of Sharpsburg silty clay loam soil, containing 1% by weight of incorporated alfalfa, sorghum and corn stover residue, were placed in petri dishes, autoclaved, wetted to 40% moisture, and incubated at 24°C. for periods of 2, 3, and 4 weeks. One-half of the petri dishes were inoculated withP. urticae. Germination and seedling-shoot measurements were taken after 7 days of growth.The results of this study showed that (1) inoculation of soil generally reduced seedling height regardless of the residue treatment; (2) inoculation of soil containing corn and sorghum residues resulted in greater tissue production but reduced height of seedlings as compared to non-inoculated soils; and (3) in the absence of residues, the inoculated control soils were a better growth medium for wheat seedlings than were the non-inoculated control soils. In addition, alfalfa residues, especially in the presence ofP. urticae, were strongly inhibitory to the wheat seedlings, causing curling and reduced wheat-seedling root growth.Joint contribution from University of Nebraska and Soil and Water Conservation Research Division, Agricultural Research Service, U.S. Department of Agriculture, and Nebraska Agricultural Experiment Station, Lincoln, Nebraska, cooperating. Published with the approval of the Director as Paper No. 1242, Journal Series, Nebraska Agricultural Experiment Station.     

The physical location of fourteen RFLP markers in rice (Oryza sativa L.)

A biotin-labeled in situ hybridization technique was used in order to physically map RFLP markers to the chromosomes of rice (Oryza sativa L.). Fourteen RFLP markers, associated with the ends of the linkage groups on rice chromosomes 7, 8, 11, 12, were physically mapped onto specific regions of the chromosomes. The average detection rate of in situ hybridization was 5.91%. The markers were located on seven different chromosome arms. Ten of the fourteen markers were distributed near the chromosome ends. This demonstrated that the RFLP linkage groups involved covered a wide physical distance and that the centromeric region was bisected by all but one linkage group. Two markers covered a short genetic distance but were physically distant, while two covering a longer genetic distance were physically closer together. This indicates that considerable variation can, and does, exist between genetic and physical maps.This paper is a contribution of the U.S. Department of Agriculture, Agricultural Research Service, and Missouri Agricultural Experiment Station, Journal Series No. 11 882All programs and services of the U.S. Department of Agriculture are offered on a nondiscriminatory basis without regard to race, color, national origin, religion, sex, age, marital status, or handicapThis paper reports the results of research only. Mention of a proprietary product does not constitute an endorsement or a recommendation for its use by the U.S. Department of Agriculture or the University of Missouri     

Linkages among zein genes determined by isoelectric focusing

Summary Genetic control of the major zein polypeptides in maize (Zea mays L.) was studied by isoelectric focusing (IEF) in agarose. Linkage relationships were determined by making a number of crosses, then determining the expression of zein polypeptides in backcross seeds. Chromosome linkages were determined by using the markers sugary-1 (for chromosome 4), yellow-8, and a waxy 7–9 translocation (for chromosome 7). Nine zeins were in one linkage group on chromosome 4, six in another linkage group on chromosome 4, and four zeins were in one linkage group on chromosome 7. Some IEF single bands consisted of at least two polypeptides, which were detected by subsequent sodium dodecyl sulfate polyacrylamide gel electrophoresis, by aberrant ratios in backcrosses, or by differing recombination percentages. One zein occurred only in homozygous sugary-1 seeds. Three sets of closely-linked zeins were noted that occurred together almost exclusively in certain inbreds.Cooperative investigations of the U.S. Department of Agriculture, Agricultural Research Service, and the Illinois Agricultural Experiment Station, Department of Agronomy, University of Illinois, Urbana, USAMention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned     

Jasmonic acid-dependent increases in the level of specific polypeptides in soybean suspension cultures and seedlings

Adding 2–30 M jasmonic acid (JA) to photomixotrophic suspension cultures of soybean increased the level of several soluble polypeptides isolated by SDS-PAGE. The major polypeptides affected by JA treatment were at M_r 31,200 (p31) and M_r 39,000. Spraying leaves of soybean seedlings with 10–50 M JA also increased the level of several soluble polypeptides including p31. The use of Con A affinity chromatography demonstrated that p31 was a glycoprotein and that JA increased the level of three other glycoproteins at M_r 22,000, 33,000, and 52,000. The JA treatment did not alter the growth or morphology of the seedlings. JA at 2–30 M did not significantly inhibit the growth of the cultured cells and did not significantly alter the chlorophyll concentration. However, JA at concentrations above 30 M inhibited growth and chlorophyll levels in cultured cells. The suspension cultured cells could provide a reliable bioassay for jasmonic acid.This paper represents cooperative investigations of the U.S. Department of Agriculture, Agricultural Research Service, and the North Carolina Agricultural Research Service, Raleigh, North Carolina 27695-7601. Paper No. 10997 of the journal series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7601.Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture or the North Carolina Agricultural Research Service and does not imply its approval to the exclusion of other products that may also be suitable.     

Plant nucleases. IV. Genetic control of ribonuclease activity in corn endosperm

Ribonuclease activity in the endosperms of 14 corn (Zea mays L.) inbreds ranged from 285 to 1305 units/g fresh weight 50 days after pollination. Activity is low in the inbred M14 and high in the inbred WF9. Hybrid endosperms contain intermediate levels of ribonuclease, and segregation occurs in the F₂ generation. The ribonuclease contents of the opaque-2 versions of nine inbred lines ranged from 1288 to 5110 units/g. The floury-2 mutation apparently does not affect ribonuclease content. Two or more genes may be involved in the control of ribonuclease content of developing endosperms.Cooperative investigations of the Plant Science Research Division, Agricultural Research Service, U.S. Department of Agriculture, and the Illinois Agricultural Experiment Station, Urbana, Illinois.     

Isolation of viridicatin from Penicillium palitans

Summary Viridicatin, C₁₅H₁₁O₂N, has been shown to be a metabolic product of several fungi including P. palitans, P. olivino-viride, P. puberulum, P. martensii, P. crustosum, P. granulatum, and P. cyclopium. Although these strains also produce the tremorgenic mycotoxin, tremortin, no toxicity could be shown for viridicatin. Viridicatin does not appear to be a component of the tremortin molecule. A quantitative colorimetric assay has been developed for viridicatin.This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture. Mention of firm names or trade products does not imply that they are endorsed or recommended by the Department of Agriculture over other firms or similar products not mentioned.     

Effect of EDTA on two RNases from wheat leaves

Two RNases, designated WL-RNase I and II, were separated fromextracts of senescing wheat leaves. WL-RNase II, but not WL-RNaseI, was inhibited by EDTA. A period of time was necessary forthe full effect of EDTA to be observed. Zinc ions abolishedthe EDTA effect. ¹Most of the data are taken from a Ph. D. Thesis submitted tothe University of London by L. SODEK. A portion of the workwas cooperative between the University of Illinois and the U.S.Dept. of Agriculture. Mention of a trademark or proprietaryproduct does not constitute a guarantee or warranty of the productby the U.S. Dept. of Agriculture, and does not imply its approvalto the exclusion of other products that may also be suitable ²Research Chemist, Crops Research Division, Agricultural ResearchService, United States Department of Agriculture (Received October 3, 1969; )     

Vacuolar protein bodies in tomato leaf cells and their relationship to storage of chymotrypsin inhibitor I protein

Summary Electron microscopy of leaves of tomato has shown that tissue containing chymotrypsin inhibitor I protein has protein in the cell vacuoles. The vacuolar protein was found either as many small bodies or as few large bodies. The data indicate that the vacuole is a temporary storage site for protein which may play an important role in growth and development of the plant. This strongly suggests that the plant-cell vacuole is something more than a site for terminal deposition of waste products. The system offers an unusual opportunity to study the biochemistry and ultrastructure of synthesis, vacuolar deposition, and recall of a well-characterized plant protein.This work was supported in part by Washington State Medical and Biological funds, U.S. Public Health Service Grants 2K3GM17059 and GM12505, and by U.S.D.A. C.S.R.S. Grant No. 915-15-29. College of Agriculture scientific paper 3442, Projects 1791 and 1996.Program in Genetics and Department of Botany.Department of Agricultural Chemistry.Department of Agricultural Chemistry. Research Career Development Awardee of the U.S. Public Health Service.     

Resistance of maize to Meloidogyne arenaria and Meloidogyne javanica

Summary A diallel cross of eight maize, Zea mays L., inbred lines was analyzed for reaction to two species of root-knot nematodes, Meloidogyne arenaria (Neal) Chitwood and M. javanica (Treub) Chitwood. Egg production following inoculation of F₁ hybrid seedlings with nematode eggs was determined in a greenhouse experiment. Data were analyzed using Griffing's Method 4, Model I. General combining ability was a significant source of variation in egg production of both M. arenaria and M. javanica; specific combining ability was not a significant source of variation for either. The correlation between egg production of the two nematode species on the 28 F₁ hybrids was highly significant. Hybrids with Mp313 or SC213 as one parent were the most resistant to both species. This indicates that germ plasm is available for developing inbred lines and hybrids with resistance to both M. arenaria race 2 and M. javanica.This article is a contribution of the Crop Science Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, in cooperation with the Mississippi Agricultural and Forestry Experiment Station, Journal No. J-7481.     

Copper as essential to wheat reproduction

Summary The role of Cu in promoting the reproductive phase of growth was examined using Thatcher spring wheat (Triticum aestivum L.). Plants were grown in limed Bladen soil (pH 5.3) in a controlled growth room. The plants were first harvested when five leaves had developed (day 23) and some top leaves of Cu-deficient (-Cu) plants had rolled (withertip) indicating a Cu deficiency. The leaves were shorter on Cu than Cu-sufficient (+Cu) plants, and fewer leaves developed. As they entered the reproductive growth phase, +Cu plants accumulated reducing sugars and reduced 2, 3, 5- triphenyltetrazolium chloride (TTC) in their stems, while Cu plants had lower concentration of the reducing sugars and very little TTC was reduced indicating a reduction in energy and in reducing capacity. Thin-layer-chromatography showed that top leaves of Cu plants contained higher concentrations of aspartic acid, alanine, and serine; and less aminobutyric acid than +Cu plants. Nitrate, P, and K concentrations were higher, and Ca and Cu were lower in Cu than in +Cu plants.Contribution of U.S. Department of Agriculture, Agricultural Research Service, Plant Stress Laboratory, Northeast Region, Beltsville, MD 20705 and North Central Region, Department of Agronomy, University of Nebraska, Lincoln, NE 68583 as Paper No.5187, Journal Series, Nebraska Agricultural Experiment Station.Contribution of U.S. Department of Agriculture, Agricultural Research Service, Plant Stress Laboratory, Northeast Region, Beltsville, MD 20705 and North Central Region, Department of Agronomy, University of Nebraska, Lincoln, NE 68583 as Paper No.5187, Journal Series, Nebraska Agricultural Experiment Station.     

Rescuing abortive inter-EBN potato hybrids through double pollination and embryo culture

Summary Regeneration of inter-EBN hybrids among potato species was achieved using embryo rescue techniques. Tetraploid hybrids between 4x(2EBN) Solanum stoloniferum x 4x(4EBN) S. tuberosum Gp. Andigena as well as diploid hybrids between 2x(1EBN) S. chancayense x 2x(2EBN) S. chacoense were obtained by culturing immature hybrid embryos in nutrient medium. Identification of appropriate embryo developmental stages was critical in developing a suitable protocol for rescuing viable hybrid embryos. The use of IVP clones as the second pollinator in 4x(2EBN) x 4x(4EBN) crosses reduced premature fruit drop and helped to identify triploid hybrids. Morphological and cytological examination confirmed true hybridity for a few of the regenerated plants. Male sterility and meiotic abnormalities were characteristic of the hybrids. Several S. stoloniferum-Andigena hybrids were successfully backcrossed to Gp. Andigena.Cooperative investigation of Vegetable Crops Research Unit, USDA, Agricultural Research Service, and the Wisconsin Agricultural Experiment Station Note: Reference to a specific brand or firm name does not constitute endorsement by the U.S. Department of Agriculture over others of similar nature not mentioned     

Antimicrobial activity of naphthoquinones from Fusaria

Twenty-two naphthoquinone compounds isolated or derived synthetically from culture extracts ofFusarium solani andF. oxysporum were examined for antimicrobial activity. Fifteen exhibited antibiotic activity againstStaphylococcus aureus, and 12 were active againstStreptococcus pyogenes, but none were active at the highest rate of 128 g/ml againstEscherichia coli, Klebsiella pneumoniae, Salmonella typhi, Proteus vulgaris, Serratia marcescens, orPseudomonas aeruginosa. Of 8 plant pathogenic bacteria tested against 11 naphthoquinones,Corynebacterium poinsettiae was inhibited by 6 compounds, andPseudomonas viridiflava was weakly inhibited by one. Only one of a group of 6 fluorescent soil pseudomonads was inhibited by one naphthoquinone. Antifungal activity of 10 compounds against 8 fungal plant pathogens was limited to inhibition ofPhytophthora parasitica by one naphthopyran.South Atlantic, Agricultural Research Service, U.S. Department of Agriculture. Mention of a trademark or proprietary product is for identification only and does not imply a warranty or guarantee of the product by the U.S. Department of Agriculture over other products which may also be suitable.     

The development of monoclonal antibodies against the cytokinin zeatin riboside

Seven monoclonal anti-zeatin riboside antibodies were characterized by radioimmunoassay (RIA) and found to measure femtomole (10^–15 M) quantities (20 pg) of this cytokinin. The antibodies had different measuring ranges defined by the linear portion of the logit/log plots; slopes and intercepts of the line varied considerably between the antibodies. Competitive binding trials againstcis-zeatin riboside (cZR), dihydrozeatin riboside (diHZR), zeatin (Z), and isopentenyl adenosine (iPA) showed differences among the seven antibodies in their cross-reactivities towards these structurally related cytokinins. It was possible to combine selected antibodies to provide a mixture with a predictable measuring range and cross-reactivity; the ability to prepare a highly specific reagent in this manner with well-defined reactivity was noted and differences between monoclonal antibody and polyclonal antiserum probes for measurement of cytokinins were discussed.The research was supported by the Agricultural Research Service, U.S. Department of Agriculture, Technical Paper No. 7373 of the Oregon Agricultural Experiment Station. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply approval to the exclusion of other products that may also be available.     

Absence or presence of glucose in growth medium and its effect on heat injury inStaphylococcus aureus

Summary Staphylococcus aureus 196E, when grown in a glucose (0.25% wt./vol.)-containing medium, produced cells that would undergo injury when subjected to sublethal heat conditions (45 min at 50°C); however, if glucose was omitted from the growth medium, the extent of injury was greatly reduced. Media containing glucose sterilized by filtration or by separate autoclaving produced cells equal in injury susceptibility to medium in which glucose was autoclaved as part of the medium components. Injury also occurred when other sugars such as fructose, mannose, maltose, or lactose were substituted for glucose. Sugar-containing media that producedStaphylococcus aureus of maximal susceptibility to heat injury reached a pH of approximately 6 or lower during growth of the cells. Incubation of staphylococci in growth medium acidified with acetic or lactic acids or HCl did not lead to cells that would undergo injury under the stated conditions. The stimulatory effect of glucose on injury appears to be related to the metabolism of the sugar byStaphylococcus aureus.Agricultural Research Service, U.S. Department of Agriculture. Reference to brand or firm name does not constitute endorsement by the U.S. Department of Agriculture over others of a similar nature not mentioned.     

Ultrastructure of primary sporidia of a wheat-bunt fungus,Tilletia caries,during ontogeny and mating

Summary Primary sporidia ofTilletia caries (DC.) Tul. are borne on denticles at the tips of promycelia. The promycelia contain many small vacuoles and mitochondria and numerous lipid bodies. As the primary sporidia develop, the promycelial cytoplasm passes into the nascent cells. Septa develop between the bases of mature sporidia and the tips of the denticles. Sporidia that abscise from the denticles commonly have prominent birth scars at their bases. The sporidia have very thin walls, few vacuoles, attenuated mitochondria, and numerous lipid bodies. Conjugation pegs are generally produced by both members of a conjugating pair of sporidia and there are bud scars where they emerge from the sporidia. The sporidial walls are apparently hydrolyzed during emergence of the pegs. Vesicles are sometimes present at the tips of the conjugation pegs and, before fusion, electron-dense accumulations are sometimes observed between the tips of adjacent pegs. The approaching conjugation pegs are precisely aligned prior to fusion, suggesting polar communication. The walls of the conjugation pegs fuse and then are hydrolyzed. Fused sporidia are relatively homogeneous in content. The nucleus in a sporidum is often close to the conjugation tube and occasionally is partly within the fusion tube.Cooperative investigations of the Oregon Agricultural Experiment Station, Brigham Young University, and Science and Education Administration-Agricultural Research, U.S. Department of Agriculture. Technical Paper No. 4,934 of the Oregon Agricultural Experiment Station. Mention of a trademark or proprietary product does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.     

Gene-dependent flavonoid glucosyltransferase in maize

A direct relationship between a specific gene and a specific enzyme involved in flavonoid biosynthesis is reported for the gene Bz and uridine diphosphoglucose: quercetin glucosyltransferase in maize pollen, seedlings, and seeds. Ratios are presented for specific activities of the glucosyltransferase from pollen, seed, and seedling tissues homozygous and heterozygous for Bz and homozygous for bz.Cooperative Investigations, Agricultural Research Service, United States Department of Agriculture and Missouri Agricultural Experiment Station, Columbia, Missouri 65201. Journal Series No. 7340.     

Patulin effects on wheat plants in field treatments

Summary Fall field patulin applications (500 µg/g of soil) to Cheyenne winter wheat seedlings at growth stages 0, 1, and 2, decreased germination, plant growth, winter survival, and tillering. Decreased tillering decreased the number of heads and grain yield. Spring patulin application of 250 and 500 µg/g of soil to wheat at growth stages 6, 7, 8, 9, and 10 decreased yields by decreasing the number of heads, kernels per head, and kernel weight. With fall patulin applications, yields were decreased more when patulin was applied near seeding. Spring patulin applications to wheat during sensitive heading stages decreased yield the most.Stages of wheat growth especially susceptible to patulin are the germination, stem-elongation, and flowering, which occur during the fall and spring when soil Penicillium urticae Bainier numbers are maximun and patulin has been extracted from the soil.Contribution from the Soil, Water, and Animal Waste Management Research Unit, North Central Region, Agricultural Research Service, U.S. Department of Agriculture, in cooperation with the Nebraska Agricultural Experiment Station, Lincoln. Published as Paper No. 4071, Journal Series, Nebraska Agricultural Experiment Station.Microbiologist, USDA, A.R.S. University of Nebraska, Lincoln; Soil Scientist, USDA, A.R.S. Fort Collins, Colorado; and Microbiologist, USDA, A.R.S. University of Nebraska, Lincoln, respectively.