Biochemical and spectroscopic characterization of morning glory peroxidase from an invasive and hallucinogenic plant weed Ipomoea carnea

A novel heme peroxidase MGP from the latex of Ipomoea carnea subsp. fistulosa (morning glory) belonging to the Convolvulaceae family was purified to homogeneity using ammonium sulfate precipitation, anion exchange, hydrophobic interaction, and gel filtration chromatography. The enzyme is glycosylated and has a molecular mass of 42.06 kDa (MALDI-TOF) and an isoelectric point of pH 4.3. The enzyme has high yield, broad substrate specificity, and a high stability toward pH, temperature, chaotrophs, and organic solvents. The extinction coefficient (epsilon 280 (1%)) of the enzyme was estimated as 20.56 and it consists of 13 tryptophan, 9 tyrosine, and 8 cysteine residues forming 4 disulfide bridges. There is significant effect of inhibitors targeting S-S bridges (mercaptoethanol, l-cysteine, glutathione), as well as of inhibitors targeting heme (sodium azide and hydroxylamine) on peroxidase activity, whereas inhibition was not observed with ethylmaleinimide due to the absence of reduced cysteine in the enzyme. Polyclonal antibodies against the enzyme have been raised in rabbit, and immunodiffusion suggests that the antigenic determinants of MGP are unique. The N-terminal sequence of MGP (D-E-A-C-I-F-S-A-V-K-E-V-V-D-A) exhibited considerable similarity to the sequence of other known plant peroxidases. Spectroscopic studies (absorbance, fluorescence, and circular dichroism) reveal that MGP has secondary structural features with alpha/beta type with approximately 20% alpha-helicity.     

Water use and carbon exchange of red oak- and eastern hemlock-dominated forests in the northeastern USA: implications for ecosystem-level effects of hemlock woolly adelgid

Water use and carbon exchange of a red oak-dominated (Quercus rubra L.) forest and an eastern hemlock-dominated (Tsuga canadensis L.) forest, each located within the Harvard Forest in north-central Massachusetts, were measured for 2 years by the eddy flux method. Water use by the red oak forest reached 4 mm day(-1), compared to a maximum of 2 mm day(-1) by the eastern hemlock forest. Maximal carbon (C) uptake rate was also higher in the red oak forest than in the eastern hemlock forest (about 25 versus 15 micromol m(-2) s(-1)). Sap flux measurements indicated that transpiration of red oak, and also of black birch (Betula lenta L.), which frequently replaces eastern hemlock killed by hemlock woolly adelgid (Adelges tsugae Annand.), were almost twice that of eastern hemlock. Despite the difference between species in maximum summertime C assimilation rate, annual C storage of the eastern hemlock forest almost equaled that of the red oak forest because of net C uptake by eastern hemlock during unusually warm fall and spring weather, and a near-zero C balance during the winter. Thus, the effect on C storage of replacing eastern hemlock forest with a forest dominated by deciduous species is unclear. Carbon storage by eastern hemlock forests during fall, winter and spring is likely to increase in the event of climate warming, although this may be offset by C loss during hotter summers. Our results indicate that, although forest water use will decrease immediately following eastern hemlock mortality due to the hemlock woolly adelgid, the replacement of eastern hemlock by deciduous species such as red oak will likely increase summertime water use over current rates in areas where hemlock is a major forest species.     

Genes conferring low seedling reaction to Mexican pathotypes of Puccinia recondita f. sp. tritici,and adult-plant responses of recent wheat cultivars from the former USSR

Fifty-five spring bread wheat (Triticum aestivum L.) cultivars, mostly released between 1975 and 1991 in eight leaf rust-prone spring wheat growing regions of the former USSR, were tested in the seedling growth stage for reaction to 15 Mexican pathotypes of Puccinia recondita f. sp. tritici. In total, seven known and at least two unknown genes were identified, either singly or in combinations: Lr3 (7 cultivars), Lr10 (14), Lr13 (5), Lr14a (1), Lr16 (1), Lr23 (3); the unknown genes were identified in 14 cultivars. The first unknown gene could be either Lr9, Lr19, or Lr25; however, the second unknown gene in 9 cultivars was different from any named gene. Twelve of the 15 pathotypes are virulent for this gene, hence its use in breeding for resistance will be limited. The cultivars were also evaluated at two field locations in Mexico with two pathotypes in separate experiments. The area under the disease progress curve and the final disease rating of the cultivars indicated genetic diversity for genes conferring adult plant resistance. based on the symptoms of the leaf tip necrosis in adult plants, resistance gene Lr34 could be present in at least 20 cultivars. More than half of the cultivars carry high to moderate levels of adult plant resistance and were distributed in each region.     

Molecular phylogeny and pathotyping of Fusarium solani: a causal agent of Dalbergia sissoo decline

Sissoo (Dalbergia sissoo), commonly known as shisham, is amongst the finest woods of South Asia, but ‘wilt’ disease has caused a rapid decline in this species. The cause of the disease remains uncertain. The aim of this study is to identify the causal agent of the disease and characterize isolates made from diseased trees, based on genomic data and variations in virulence. Samples of infected roots, stems and the ooze exuded from infected trees were obtained from plants showing symptoms in different geographical regions of India for the isolation of microorganisms. Isolates were used to inoculate healthy plants. Based on the morphological characteristics, genus‐ and species‐specific PCR, and in silico analysis of 5.8S rDNA‐ITS regions, of the 38 fungal isolates, 24 and 14 were identified as Fusarium solani and Fusarium sp., respectively. In a pathotyping study, eighteen F. solani isolates, isolated from roots and stem parts of symptomatic plants, induced typical wilt symptoms when inoculated through soil and roots on D. sissoo seedlings of 1–15 months in age. The population of F. solani was the highest in infected roots and the lowest in parts of stems, gradually decreasing with height, and was isolated constantly up to approximately 40% height of the seedling. F. solani isolates used in inoculations were successfully re‐isolated from the rhizosphere, infected roots and wilted stems, as confirmed using isolate‐specific DNA fingerprints. Molecular phylogenies based on rDNA‐ITS sequences showed that the 38 isolates fell into 2 groups. Group I comprised of F. solani isolates from D. sissoo and F. solani sequences in the NCBI GenBank database, whereas group II included Fusarium isolates other than F. solani. These results are helpful in developing integrated control measures for this highly variable pathogen and to establish a base for future population studies.     

Phosphorus Enhanced Establishment,Growth, Nutrient Uptake,and Productivity of Dalbergia sissoo Seedlings Maintained at Varying Soil Water Stress Levels in an Indian Arid Zone

We assessed interactive effects of varying levels of applied phosphorus fertilizer and water stress on growth, productivity, and mineral accumulation in container-grown Dalbergia sissoo L. seedlings. Height, collar diameter, leaf size and area, root volume and total biomass were reduced, and dry matter allocation to root was increased with increasing levels of soil water stress. The reduction was >32% in growth, >50% in leaf, and >77% in biomass when seedlings were grown with <50% of soil field capacity. Phosphorus application at the level of 10 mg kg^?1 soil enhanced stems and leaf biomass and nutrient accumulation at all irrigation levels, and thus tolerance to drought. Phosphorus responses to growth and biomass production increased with irrigation levels. Thus, 20 mg P kg^?1 soil is beneficial at sufficient soil water availability and a lower dose (i.e., 10 mg P kg^?1) is recommended under high soil water stress conditions to benefit growth and productivity of D. sissoo.     

Intercropping field crops between rows of Leucaena leucocephala under rainfed conditions in northern India

A field study was conducted for six years (1981–1986) on sandy loam soil on intercropping hedgerows of Leucaena leucocephala (Lam) de Wit. with three field crops viz. maize (Zea mays L), black gram (Vigna mungo L) and cluster bean (Cyamopsis tetragonoloba L Taub.). In treatments 1 and 2 Leucaena hedges were planted as pure crops at close (25 cm × 75 cm) and wide (25 cm × 375 cm) spacings. In treatments 3, 4 and 5 the three field crops were intercropped between the hedgerows of Leucaena at the wide spacing, and in treatments 6, 7 and 8 the field crops were raised as pure crops. Leucaena was topped to 75 cm each time it attained a height of 175 cm. The pure crop of Leucaena at close spacing produced an average, over the six years, of 34 t ha⁻¹a⁻¹ of green fodder and 9.4 t ha⁻¹a⁻¹ of air dry fuelwood. The Leucaena at wide spacing produced 18.9 t ha⁻¹a⁻¹ of green fodder and 6.3 t ha⁻¹a⁻¹ of fuelwood. Intercropping with field crops decreased the yield of green fodder and fuelwood. The yield of all the field crops was less when raised as intercrops than as pure crops. Mean maximum net returns were obtained from intercrops of Leucaena and cluster bean (Rs 3540 ha⁻¹a⁻¹) which were significantly higher than the returns from pure crop of Leucaena at wide spacing but similar to the returns from pure crops of cluster bean. Leucaena with maize (Rs 3273 ha⁻¹a⁻¹) and black gram (Rs 3125 ha⁻¹a⁻¹) gave significantly higher net returns over pure crops of Leucaena at wide spacing, maize and black gram. ICRISAT = International Crops Research Institute for the Semi-Arid Tropics- Hyderabad, India. CIAT = Centro International de Agricultura Tropical - Cali - Columbia     

Adventitious rhizogenesis in Bambusa nutans and Bambusa tulda: Influence of seasonal variation, IBA and cutting type

The influence of seasonal variation, indole-3-butyric acid (IBA) and type of cuttings was examined on induction and growth of adventitious roots in Bambusa nutans Wall. and Bambusa tulda Roxb. Singlenode culm and culm-branch cuttings from the mature culms were provided with immersion treatment for 24 h of either water (control) or 2 mM IBA in four different seasons, i.e., spring (mid February), summer (mid May), rainy (mid July), and winter (mid November) and maintained for two months in the mist chamber at the relative humidity of (70±5)% and the temperature of (30±2)°C. In B. nutans, adventitious rooting occurred in both types of cuttings in all the seasons with the best rooting in the summer season i.e., May (88% in culm cuttings) and the least in winter. On the contrary, adventitious rooting was recorded only in culm cuttings in spring and summer season in B. tulda. IBA treatment significantly enhanced rooting, root number and root length; registering 14 to 17 times improvement over control in the best rooting season. Three factor-interactions (season × cutting type × IBA treatment) were significant for rooting in B. nutans and all characteristics, except sprouting in B. tulda. Thus, single-node culm and culm-branch cuttings in B. nutans and culm cuttings in B. tulda treated with 2 mM IBA during spring (February) to summer (May) season are recommended for their clonal multiplication.     

Experimental evaluation of the culture performance of three exotic and a ‘local’ Giant Freshwater Prawn (Macrobrachium rosenbergii,De Man 1879) culture strain in Fiji

Giant freshwater prawn (GFP; Macrobrachium rosenbergii) aquaculture has expanded rapidly since 1990. Most local culture industries, however, have developed in an unsystematic way. Fiji has a small culture industry producing the ‘Anuenue’ strain; however, performance of this strain has never been systematically evaluated. Recently, some Fijian farmers have reported declines in stock productivity. The current project evaluated the relative performance of three exotic strains with different genetic backgrounds from Malaysia, Indonesia and Vietnam, against the ‘local’ strain in Fiji in a 4 × 3 replicated pond trial experiment. A total of 5827 prawns were harvested after 143 days growout. Individual growth rate and relative survival of the Fiji strain were not statistically different from any of the introduced strains, but Vietnam strain was superior to that of the Malaysia strain. Genetic diversity showed significant differences in variability among strains, with the Malaysian strain displaying the lowest genetic diversity. Indonesia strain showed that females were reaching maturation earlier than other strains and were smaller in size. This study suggests that Malaysian and Indonesian strains would constitute a poor choice for Fiji, whereas the Vietnam strain consistently performed well on all criteria measured. High variation among replicate ponds within strains unfortunately confounded among‐strain variation.     

Micronutrient availability in soils of Northwest Bosnia and Herzegovina in relation to silage maize production

Maize (Zea mays L.) is the most widely grown crop in Bosnia and Herzegovina especially in Northwest part of the country. Considering that, the maize is extremely sensitive to micronutrient deficiency the main aim of this study was to asses: (1) micronutrient availability in soil, (2) micronutrient status in silage maize; and (3) the relationship between micronutrient soil availability and maize plant concentration. Soil samples for micronutrient availability (n?=?112) were collected from 28 farms in 7 municipalities. Plant available micro- and macro- nutrients in soil were extracted using Mehlich-3, except plant available Se was extracted using 0.1M KH₂PO₄. Result showed that on average there was no significant difference between different soil types regarding their potential in plant available nutrients. P deficiency was present both, in soil and plants in whole region. Soil extractable P was ranging from 0.003–0.13?g?kg^?1 and total plant P was ranging from 0.79–4.95?g?kg^?1. Zinc deficiency was observed in two locations both in soil (0.71?mg?kg^?1; 0.79?mg?kg^?1) and plant (11.5?mg?kg^?1; 15.8?mg?kg^?1). Potential Se soil deficiency was observed on some locations, while Se plant status is not high enough to meet daily requirements of farm animals. Extractable soil nutrients could be used as relatively good predictor of potential soil and plant deficiencies, but soil nutrient interactions and climate conditions are highly effecting the plant uptake potential.     

Comparison of oil and phytosterol levels in germplasm accessions of corn, teosinte, and Job's tears

Seeds of 49 accessions of corn (Zea mays ssp. mays), 9 accessions of teosinte (Zea species that are thought to be ancestors and probable progenitors to corn), and 3 accessions of Job's tears (Coix lacryma), obtained from a germplasm repository, were ground and extracted with hexane. Whole kernel oil yields and levels of four phytonutrients (free phytosterols, fatty acyl phytosterol esters, ferulate phytosterol esters, and gamma-tocopherol) in the oils were measured. Among the seeds tested, oil yields ranged from 2.19 to 4.83 wt %, the levels of ferulate phytosterol esters in the oil ranged from 0.047 to 0.839 wt %, the levels of free phytosterols in the oil ranged from 0.54 to 1.28 wt %, the levels of phytosterol fatty acyl esters in the oil ranged from 0.76 to 3.09 wt %, the levels of total phytosterols in the oil ranged from 1.40 to 4.38 wt %, and the levels of gamma-tocopherol in the oil ranged from 0.023 to 0.127 wt %. In general, higher levels of all three phytosterol classes were observed in seed oils from accessions of Zea mays ssp. mays than in seed oils from accessions of the other taxonomic groups. The highest levels of gamma-tocopherol were observed in teosinte accessions.