Kinetin regulates plant growth and biochemical changes during maturation and senescence of leaves,flowers, and pods of <Emphasis Type="Italic">Cajanus cajan</Emphasis> L.

Aspects of plant growth such as height, branch number, leaf number, leaf area, pod area, 100-seed mass, etc., were correlated with biochemical changes such as contents of chlorophyll (Chl), proteins, DNA, and RNA, and protease activity during development and senescent phases in leaves, flowers, and pods of Cajanus cajan L. cv. UPAS-120 after treatments with kinetin (Kn). A significant increase was noticed in branch number, leaf number, leaf area, and seed mass while other growth processes registered a small increase after Kn application. Effectiveness of 5 μM Kn was also noticed in minimizing the loss of Chls, proteins, and nucleic acids as well as reducing the protease activity during maturity and senescence. Chl a/b ratio maintained a high value up to 30-d followed by a decline in leaves while flowers registered much lower ratio at 20-d-age. Pods were unique in having relatively lower ratio of Chl a/b in comparison to leaves.     

新疆两种光脉赤眼蜂雌性触角超微结构比较(膜翅目:赤眼蜂科)

观察并描述了采自新疆的土耳其光脉赤眼蜂Aphelinoidea anatolica Nowicki和沙湾光脉赤眼蜂AphelinoideashawanicaHuetLin雌蜂触角的超微结构特征,结果显示2种光脉赤眼蜂雌性触角上的感器种类、数目及形状存在差异,这种差异可以作为种类鉴定的参考依据。同时提供了新疆光脉赤眼蜂属分种检索表及电镜扫描图片。     

亚洲玉米螟成虫触角的扫描电镜观察

对亚洲玉米螟成虫触角的外部形态结构在扫描电镜下作了观察.触角由柄节、梗节和62—67个鞭节组成,触角背面被鳞片覆盖,绝大部分触角感器位于触角的腹面和侧面.所有鞭节的表皮上都有连续的网纹结构,但在柄节和梗节的表皮上则无.在雌雄蛾的触角上都可以找到以下七种感器,即栓锥感器、腔锥感器、锥形感器(即B?hm氏鬃毛)、刺形感器、耳形惑器、鳞形感器和毛形感器.毛形感器数目最多,并根据其形状和表面细微结构分为两种类型:A型和B型.除锥形感器外,所有的感器都分布在触角鞭节的网纹区上.对此昆虫的触角两性差异进行了详细的讨论.     

Functional phycobilisome core structures in a phycocyanin-less mutant of cyanobacterium Synechococcus sp. PCC 7942

We have constructed a mutant Synechococcus sp. PCC 7942, termed R2HECAT, in which the entire phycobilisome rod operon has been deleted. In the whole cell absorption spectra of R2HECAT, the peak corresponding to phycocyanin (PC), max620 nm, could not be detected. However, a single pigment-protein fraction with max=654 nm could be isolated on sucrose gradients from R2HECAT. Analysis of this pigment-protein fraction by non-denaturing PAGE indicates an apparent molecular mass of about 1200–1300 kDa. On exposure to low temperature, the isolated pigment-protein complex dissociated to a protein complex with a molecular mass of about 560 kDa. When analysed by SDS-PAGE, the pigment-protein fraction was found to consist of the core polypeptides but lacked PC, 27, 33, 30, and the 9 kDa polypeptides which are a part of the rods. All the chromophore bearing polypeptides of the core were found to be chromophorylated. CD as well as absorption spectra showed the expected maxima around 652 and 675 nm from allophycocyanin (APC) and allophycocyanin B (APC-B) chromophores. Low temperature fluorescence and excitation spectra also showed that the core particles were fully functional with respect to the energy transfer between the APC chromophores. We conclude that PC and therefore the rods are dispensable for the survival of Synechococcus sp. PCC 7942. The results indicate that stable and functional core can assemble in absence of the rods. These rod-less phycobilisome core is able to transfer energy to Photosystem II.Abbreviations PS II Photosystem II - PC phycocyanin - APC allophycocyanin - APC-B allophycocyanin B - PAGE polyacrylamide gel electrophoresis - Cml chloramphenicol - kbp kilobase pairs     

Four new species of Cymatodera Gray from Mexico (Coleoptera,Cleridae, Tillinae)

Four new species of Cymatodera from Mexico: Cymatodera bogcioides sp. n.; Cymatodera pueblae sp. n.; Cymatodera mitae sp. n.; and Cymatodera lineata sp. n. are described based on adult male and female specimens. Male genitalia and other characters of taxonomic value are presented.     

Accumulation of di-n-butylphthalate in plants and its effect on pigment and protein content

Seedlings of radish ( Raphanus salivas L. cv. Cherry Belle) and wheat ( Triticum aestivum L. cv. Starke II, Weibull) placed in air containing vapour of di- n -butyl-phthalate accumulate phthalate to a concentration that is 10⁶ times that of the surrounding air within 3 days. Particularly high accumulation is found in the cuticular and wax layers. Plants earlier found not to respond to di- n -butylphthalate (wheat) show toxic symptoms (carotenoid and chlorophyll deficiency in strong light, conco-mittant with chloroplast destruction and swollen mitochondria) when the phthalate concentration is further increased by addition to the nutrient medium. Phthalate-affected, white leaves lack the protein moieties normally belonging to the light harvesting complex.     

Localization of Near-Field Resonances in Bowtie Antennae: Influence of Adhesion Layers

The near-field resonances of gold bowtie antennae are numerically modeled. Besides the short-range surface plasmon polariton (SR-SPP) mode along the main axis of the structure, a coupled SPP mode is also found in the gap region (G-SPP). The influence of adhesion layers is considered, which depends on the refractive index and the absorption of the adhesion material and whether it is continuous or etched. A high refractive index causes the peak of the SR-SPP to red-shift. High absorption quenches the intensity of the SR-SPP. The magnitude of influence depends on the overlap of the adhesion layer with the SR-SPP and G-SPP modes. The near-field resonance of the SPP mode on the top surface is also considered. An etched metal adhesion layer changes the near-field localization in the gap and causes the enhancement peaks at different heights within the gap to red-shift from top to bottom. A simple optimization method for the near-field localization by the combination of different top and bottom layers is demonstrated.     

Pigment evolution in Lycopersicon esculentum fruits during growth and ripening

During growth and subsequent maturation, the distribution and formation of pigments in the inner pulp and in the outer region of the pericarp of ‘che     

Sensory cues and receptors for oviposition by Heliothis virescens

When given a choice of cotton (host) and ground cherry (non host) in a close range situation, Heliothis virescens (F.), the tobacco budworm, depends primarily on contact chemoreception and mechanoreception, and not olfaction or vision, to discriminate between these two plant species for oviposition. Further, in the presence of a certain level of hairiness (the non-host plant, ground cherry, has short capitate hairs), the females are capable of discriminating between these two plants based on contact chemosensory cues, if at least one pair of tarsi is intact. The contact chemosensilla on the ovipositor do not seem to be important for this purpose. These results are discussed in relation to the sensory cues and receptors for oviposition in other Lepidoptera, especially moths.

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Signaux et récepteurs sensoriels intervenant dans la ponte d'Heliothins virescens

Résumé Les différentes récepteurs sensoriels (chimique, mécanique et visuel) des femelles d'H. virescens ont été rendus inactifs par traitement à l'acide, antennotectomie ou peinture des yeux avec un enduit noir du type vernis à ongles, pour étudier le déterminisme sensoriel de la sélection des hôtes lors de la ponte; les papillons avainet le choix entre le coton (Gossypium hirsutum), sur lequel ils pondent normalement, et Physalis angulata sur lequel on n'observe pas de pontes dans la nature. Au laboratoire, à faible distance, le choix de H. virescens dépendait en premier lieu des mécanorécepteurs et des récepteurs chimiques dits de contact (gustatifs), et non de la vision ou de l'olfaction. En présence d'un certain niveau de pilosité (P. angulata possède de courts poils capités), les femelles choisissent les plantes en fonction de la perception chimique dite de contact (gustation) tant qu'une paire de tarses reste intacte. Les sensilles chimiques de l'ovitube ne semblent pas jouer un rôle important à cet égard. La discussion a examiné ces résultats à la lumière des processus sensoriels utilisés par d'autres papillons.