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1.
Pheromones of nocturnal moths are derived from fatty acids produced as a result of the activity of acetyl-CoA carboxylase. This timely production is initiated in nocturnal moths by a tropic peptide, pheromone biosynthesis activating neuropeptide released into the hemolymph. In monocotyledonous plants, specific plastid acetyl-CoA carboxylase is inhibited by herbicides that target the eukaryotic form of the enzyme. We report evidence that these herbicides can also target pheromone biosynthesis by a moth, thereby implicating the acetyl-CoA carboxylase as a key regulatory enzyme in the pheromone biosynthetic pathway. These findings, whilst indicating the possible action of such herbicides on non-target organisms, also suggest a novel alternative method of insect pest management, which precludes sex-pheromone production and mating success, thereby reducing insect population growth. 相似文献
2.
Tiago Edu Kaspary Luan Cutti Rafael Schwalm Rafaeli Carla Andrea Delatorre Aldo Merotto Jr 《Weed Research》2020,60(6):435-449
Evolution of flooding tolerance in weedy rice has occurred in several rice-growing regions, but the genes related to this process and the environmental effects are unknown. The objective of this study was to analyse the expression of genes related to flooding tolerance in response to temperature and flooding during the initial establishment of weedy rice. The experiments were carried out with rice cultivars IRGA 417 and Nipponbare, which are sensitive to flooding, and weedy rice ITJ03 and AV04 genotypes that have high and intermediate tolerance to flooding, respectively. The expression of genes related to reserve mobilisation, anaerobic respiration, escape and quiescence strategies was analysed at periods up to 24 days after sowing. The flooding tolerance of weedy rice genotype ITJ03 was associated with the expression of RAmy3D and OsTPP7 , which are involved in the mobilisation of carbohydrate reserves, ADH1 and ADH2, which participate in anaerobic respiration, and SNRKL1 that triggers rapid elongation of the coleoptile and emergence. Although the genes PDC1, SUS3 and SUB1 are important for flooding tolerance in cultivated rice, their expression was not directly related to flooding tolerance in weedy rice. A temperature of 20°C reduced levels of expression of the RAmy3D, ADH2 and SNRKL1 genes and low temperature had a negative effect on the establishment of weedy rice. Breeding of rice genotypes with tolerance of low temperatures and anaerobic conditions may be a viable strategy to improve the control of weedy rice in paddy fields. 相似文献
3.
Lili Zhou Addo-Danso Daniel Shalom Pengfei Wu Zongming He Chunhua Liu Xiangqing Ma 《林业研究》2016,27(2):357-368
Biomass production and nutrient (N, P, K, Ca and Mg) accumulation, distribution and cycling were quantified in young, mature and over-mature (10-, 22-, and 34-year old) Chinese fir [Cunninghamia lanceolate (Lamb.) Hook] plantations in southern China. Total stand biomass of young, mature and over-mature stands was 38, 104 and 138 t ha?1 respectively. Biomass production increased significantly with age. Stem wood represented the highest percentage of stand biomass, accounting for 41, 55 and 63 % in the young, mature and over-mature plantations respectively. Nutrients concentration was highest in live needles and branches, and lowest in stem wood. The plantations accumulated more N, followed by K, Ca, Mg, and P. Nutrient return amount, nutrient utilization efficiency, nutrient turnover time, the ratio of nutrient return and uptake increased with stand age, which implies that young Chinese fir deplete soil nutrients to maintain growth, and efficiently utilize nutrients to decrease dependence on soil nutrients as they age. Harvesting young Chinese fir plantations would therefore lead to high nutrient loss, but prolonging the rotation length could improve soil recovery, and help sustain productivity in the long-term. Improved nutrient return through litterfall as stands get older may also be beneficial to nutrient pool recovery. 相似文献
4.
Palm dates suffer from high infestations of sap-beetle (Coleoptera: Nitidulidae) populations. Organically grown dates are
particularly subject to high infestations for lack of alternative treatments both during pre- and postharvest, while export
requirements of null infestations are in effect. Present methods of postharvest control include treatments using CO2, which are expensive and require several hours. In this report we describe an effective, short-duration and inexpensive method
of postharvest heat-treatment using a postharvest heating container (PHHC). Laboratory experiments determined the optimum
temperature regime for maximum escape of beetles from the fruit to be 55°C for 2.5 h; this temperature was attained at a rate
of 1.8°C/min. Subsequent successful disinfestation of beetles was obtained in the PHHC after a total exposure time of 2.5
h. Sampling dates before and after treatment and quality control tests on cartons ready for export showed that this method
compared in efficiency with CO2 treatments but was much more economical. 相似文献
5.
Chen Z Appenzeller J Lin YM Sippel-Oakley J Rinzler AG Tang J Wind SJ Solomon PM Avouris P 《Science (New York, N.Y.)》2006,311(5768):1735
Single-walled carbon nanotubes (SWCNTs) have been shown to exhibit excellent electrical properties, such as ballistic transport over several hundred nanometers at room temperature. Field-effect transistors (FETs) made from individual tubes show dc performance specifications rivaling those of state-of-the-art silicon devices. An important next step is the fabrication of integrated circuits on SWCNTs to study the high-frequency ac capabilities of SWCNTs. We built a five-stage ring oscillator that comprises, in total, 12 FETs side by side along the length of an individual carbon nanotube. A complementary metal-oxide semiconductor-type architecture was achieved by adjusting the gate work functions of the individual p-type and n-type FETs used. 相似文献
6.
M. Wysoki G. Forer E. Dunkelblum Miriam Harel Polina Fraistat Devora Gordon L. Anshelevich M. Kehat M. Kehat L. Anshelevich Devora Gordon Miriam Harel E. Dunkelblum L. Zilberg A. Rubin A. Shani Ada Rafaeli Miriam Altstein Oma Ben-Aziz Irit Schafler I. Seltzer C. Gilon A. Hefetz Tamar Katzav Victoria Soroker Ali R. Harari 《Phytoparasitica》1998,26(2):175-181
7.
Yigalelad Y. Ben-Yephet Michal Reuven L Mor Shulamit Manulis C. Shoham G. Forer M. J. Berlinger Lea Bar Nir D. Wool S. Cohen D. Veierov N. Aharonson Annie Fenigstein A. R. Horowitz N. C. Toscano D. Gerung Pnina Rapid D. Gerling Shalom W. Applebaum M. Klein B. Raccah R. G. Kenneth 《Phytoparasitica》1989,17(3):223-236
8.
Lili Zhou Shalom Daniel Addo-Danso Pengfei Wu Shubin Li Xianhua Zou Yun Zhang Xiangqing Ma 《Journal of Soils and Sediments》2016,16(5):1448-1459
Purpose
The relationships among resorption, leaf nutrient status, and soil nutrient availability remain unresolved. Moreover, the dynamics of resorption in leaf and soil nutrients and stoichiometry during development of Chinese fir (Cunninghamia lanceolata) stands have rarely been studied. This study quantified the resorption efficiencies of nitrogen (N), phosphorus (P), and potassium (K), and their potential correlations with stoichiometric ratios in leaf and soil as Chinese fir stands develop, and also evaluated the nutritional control on resorption in the stands based on the “relative resorption hypothesis.”Materials and methods
Leaf and soil samples were collected from Chinese fir stands at different developmental stages (young, mature, and overmature) at the Xinkou National Forest in southern China. Samples of green leaves were collected from different portions of the crown from representative trees in different seasons. Samples of senesced leaves were collected from litter traps placed under the representative trees every month. Soils were sampled at three depths (0–20, 20–40, and 40–60 cm). Samples of green and senesced leaves were analyzed to determine nutrient (N, P, and K) concentrations, stoichiometric ratios, and resorption efficiencies. Soil samples were also analyzed for nutrient concentrations (organic matter, N, P, and K) and stoichiometric ratios.Results and discussion
P (75 %) and K (77 %) resorption efficiencies were higher than N resorption efficiency (57 %) but did not vary among the stands. However, K resorption efficiency decreased from the young to the overmature stage. N and P resorption efficiencies were influenced by season, and leaf nutrient stoichiometric ratios varied with stand stage. Green-leaf N and P concentrations, and senesced-leaf K concentration increased with stand developmental stage. The concentrations of N, P, and K decreased with soil depth, and there was no interaction effect of stand stage and soil depth on stoichiometric ratios of the soil nutrients. The correlation results showed that nutrient resorption efficiencies were mostly affected by leaf nutrient status, but seldom by soil nutrient concentration and stoichiometry.Conclusions
The results suggest Chinese fir might preferentially resorb P and K from senescing leaves prior to abscission. Based on the relative resorption hypothesis the Chinese fir plantations are more limited by P and that resorption may be an important mechanism to conserve nutrients in these stands in order to reduce dependence on soil nutrient pools. There is an indication that stand development affects these processes; however, the resorption process and internal mechanism need to be further investigated for the long term.9.
Guo X Small JP Klare JE Wang Y Purewal MS Tam IW Hong BH Caldwell R Huang L O'brien S Yan J Breslow R Wind SJ Hone J Kim P Nuckolls C 《Science (New York, N.Y.)》2006,311(5759):356-359
Molecular electronics is often limited by the poorly defined nature of the contact between the molecules and the metal surface. We describe a method to wire molecules into gaps in single-walled carbon nanotubes (SWNTs). Precise oxidative cutting of a SWNT produces carboxylic acid-terminated electrodes separated by gaps of 相似文献
10.
E. Cohen S. Ben-Yehoshua I. Rosenberger Y. Shalom B.Aro Shapiro 《The Journal of Horticultural Science and Biotechnology》2013,88(5):603-610
Storage of lemons is designed to extend the marketing of fruit throughout the year, from the main harvest season in the winter until late summer, which is a period of short supply in the market. This work was concerned with physiological and chemical attributes of stored lemons either seal-packaged in high-density polyethylene plastic film (HDPE), or left unwrapped, during storage at 13, 8 and 2°C. Intermittent warming (IW) was used to prevent chilling injury at the lower temperatures. Differences between fruit subjected to the two treatments which produced longest storage (sealed at 13°C and non-sealed at 2°C with IW) are discussed. Both treatments are recommended for adoption in commercial practice. 相似文献