Induction and Repression of CAM in Sedum telephium L. in Response to Photoperiod and Water Stress

Lee, H. S. J. and Griffiths, H. 1987. Induction and repressionof CAM in Sedurn relephluni L. in response to photopcnod andwater stress.—J. exp. Bot. 38: 834–841. The introduction and repression of CAM in Sedurn telephiunmL, a temperate succulent, was investigated in watered, progressivelydrouglited and rewatered plants in growth chambers. Measurementswere made of water vapour and CO₂ exchange, titratable acidity(TA) and xylem sap tension. Effects of photoperiod were alsostudied. CAM was induced by drought under long or short days,although when watered no CAM activity was expressed. C₃-CAM intermediate plants were used for the investigation ofwater supply. Those which had received water and those drought-stressedboth displayed a similar nocturnal increase in TA, with a day-nightmaximum (H+) of 69 µmol g^–1 fr. wt. The wateredplants took up CO₂ at a maximum rate of 2?2 µmol m^–2s^–1 only in the light period, while the droughted plantsshowed a maximum nocturnal CO₂ uptake rate of 0?69 µmolm^–2 s^–1. Subsequently, as CAM was repressed, thewatered S. telephiwn displayed little variation in TA, withconstant levels at 42 µmol g^–1 fr. wt. (day 10).After 10 d of drought stress, the CAM characteristics of S.telephiurn were aLso affected, with reduced net CO₂ uptake andH+. The transition between C₃ and CAM in S. telephium can be describedas a progression in terms of the proportion of respiratory CO₂which is recycled and refixed at night as malic acid, in comparisonwith net CO₂ uptake. Recycling increased from 20% (day 1) to44% (day 10) as a result of the drought stress and was highin both the CAM-C₃ stage (no net CO2 uptake at night) and alsoin the drought-stressed CAM stage (reduced net CO₂ uptake atnight). The complete C₃-CAM transition occurred in less than8 d, and the stages could be characterized by xylem sap tensionmeasurements: CAM = 0?50 MPa C₃-CAM = 0?36 MPa C₃ = 0?29 MPa. Key words: CAM, Sedum telephium L., recycling     

在韩国危害红松球果的三种蛾类幼虫形态记述（鳞翅目）

详细地记述了韩国红松球果害虫冷杉梢斑螟Dioryctria abietella、赤松梢斑螟D. sylvestrella (螟蛾科)和小花尺蛾Eupithecia abietaria debrunneata (尺蛾科)幼虫的形态特征,并提供了形态特征图。     

库蠓属的两个新种(双翅目:蠓科)

1982年在四川省采集吸血蠓时,发现库蠓属(culicoides)两个新种。现记述如下。新种模式标本分别保藏于四川省成都铁路局中心卫生防疫站和中国科学院动物研究所。     

A Role for Ecdysteroids in the Induction and Maintenance of the Pharate First Instar Diapause of the Gypsy Moth,Lymantria dispar

Several lines of evidence suggest a novel regulatory mechanism for diapause regulation in the gypsy moth. We propose that ecdysteroids play a role in the induction and maintenance of the pharate first instar larval diapause in this species. A 55 kDa gut protein that is indicative of diapause is expressed in intact and neck-ligated pharate larvae but is not expressed when a ligature is placed posterior to the prothorax, site of the prothoracic gland. Guts cultured in vitro for 12 h cease to synthesize the 55 kDa protein, but synthesis of the protein resumes if the culture medium is enriched with a prothorax extract from pharate larvae or a prothoracic gland extract from fifth instar larvae. Injection of 20-hydroxyecdysone or the ecdysteroid agonist, RH-5992, into isolated abdomens stimulates synthesis of the diapause-specific 55 kDa protein, suggesting that the essential factor from the prothorax is an ecdysteroid. KK-42, an imidazole derivative known to inhibit ecdysteroid biosynthesis, averts diapause when applied to prediapausing pharate first instar larvae, but this effect can be countered by application of 20-hydroxyecdysone or RH-5992, i.e. KK-42 treated pharate larvae that are exposed to an ecdysteroid or RH-5992 readily enter diapause. A chilling period (120 days at 5 degrees C) is normally adequate to prompt an immediate termination of diapause when pharate larvae are transferred to 25 degrees C, but if such larvae are held in hanging drop cultures with ecdysteroids they fail to terminate diapause. Together, these results suggest that ecdysteroids are essential for the induction and maintenance of diapause and imply that a drop in the ecdysteroid titer is essential for diapause termination. Copyright 1997 Elsevier Science Ltd. All rights reserved     

Molecular Identification of Algal Endosymbionts in Large Miliolid Foraminifera: 2. Dinoflagellates

Large miliolid foraminifers of the subfamily Soritinae bear symbiotic dinoflagellates morphologically similar to the species of the "Symbiodinium" complex, commonly found in corals and other marine invertebrates. Soritid foraminifers are abundant in coral reefs and it has been proposed that they share their symbionts with other dinoflagellate-bearing reef dwellers. In order to test this hypothesis, we have analysed partial large subunit ribosomal DNA sequences from dinoflagellates symbionts obtained from 28 foraminiferal specimens, and compared them to the corresponding sequences of Symbiodinium-like endosymbionts from various groups of invertebrates. Phylogenetic analysis of our data shows that all soritid symbionts belong to the "Symbiodinium" species complex, within which they form seven different molecular types (Frl-Fr7). Only one of these types (Fr1) branches within a group of invertebrate symbionts, previously described as type C. The remaining six types form sister groups to coral symbionts previously designed as types B, C, and D. Our data indicate a high genetic diversity and specificity of Symbiodinium-like symbionts in soritids. Except for type C, we have found no evidence for the transmission of symbionts between foraminifers and other symbiont-bearing invertebrates from the same localities. However, exchanges must have occurred frequently between the different species of Soritinae, as suggested by the lack of host specificity and some biogeographical patterns observed in symbiont distribution. Our data suggest that members of the subfamily Soritinae acquired their symbionts at least three times during their history, each acquisition being followed by a rapid diversification and independent radiation of symbionts within the foraminiferal hosts.     

Taxonomic notes on the genus Holepyris (Hymenoptera: Bethylidae) from Korea with descriptions of six new species

Six new species of the genus Holepyris (Hymenoptera: Bethylidae: Epyrinae) from Korea are described: H. brevicarinatus sp. nov., H. crinitus sp. nov., H. dimidiatus sp. nov., H. longicephalus sp. nov., H. mucro sp. nov. and H. multo sp. nov. They are described with illustrations of male genitalia and the biometric measurement data. A key to the Korean species of Holepyris based on males is provided.     

Multiple determinants influence root colonization and induction of induced systemic resistance by Pseudomonas chlororaphis O6

Colonization of the roots of tobacco by Pseudomonas chlororaphis O6 induces systemic resistance to the soft-rot pathogen, Erwinia carotovora ssp. carotovara SCC1. A screen of the transposon mutants of P. chlororaphis O6 showed mutants with about a fivefold reduction in ability to induce systemic resistance to the soft-rot disease. These mutations disrupted genes involved in diverse functions: a methyl-accepting chemotaxis protein, biosynthesis of purines, phospholipase C, transport of branched-chain amino acids and an ABC transporter. Additional mutations were detected in the intergenic spacer regions between genes encoding a GGDEF protein and fumarate dehydratase, and in genes of unknown function. The mutants in the ABC transporters did not display reduced root colonization. However, the other mutants had up to 100-fold reduced colonization levels. Generally the production of metabolites important for interactions in the rhizosphere, phenazines and siderophores, was not altered by the mutations. A reduced induction of systemic resistance by a purine biosynthesis mutant with a disrupted purM gene correlated with poor growth rate, lesser production of phenazines and siderophore and low levels of root colonization. These studies showed that multiple determinants are involved in the induction of systemic resistance, with there being a requirement for strong root colonization.     

CHANGES IN CLICK SOURCE LEVELS WITH DISTANCE TO TARGETS: STUDIES OF FREE-RANGING WHITE-BEAKED DOLPHINS LAGENORHYNCHUS ALBIROSTRIS AND CAPTIVE HARBOUR PORPOISES PHOCOENA PHOCOENA

ABSTRACT

Probably all odontocetes use echolocation for spatial orientation and detection of prey. We used a four hydrophone “Y” array to record the high frequency clicks from free-ranging White-beaked Dolphins Lagenorhynchus albirostris and captive Harbour Porpoises Phocoena phocoena. From the recordings we calculated distances to the animals and source levels of the clicks. The recordings from White-beaked Dolphins were made in Iceland and those from Harbour Porpoises at Fjord & Baelt, Kerteminde, Denmark during prey capture. We used stringent criteria to determine which clicks could be defined as being on the acoustic axis. Two dolphin and nine porpoise click series could be used to track individual animals, which presumably focused on the array hydrophones or a fish right in front of the array. The apparent source levels of clicks in the individual tracks increased with range. One individual White-beaked Dolphin and three Harbour Porpoises regulate their output signal level to nearly compensate for one-way transmission loss while approaching a target. The other dolphin regulated the output differently. For most of the recordings the sound level at the target remains nearly constant and the echo level at the animal increases as it closes on the target.     

Quantification of Flavonoid Compounds from Strawberry ( Fragaria ananassa) and Correlation Effects with Antioxidant Activities

The amounts of flavonoid (myricetin , quercetin and kaempferol), antioxidant contents ( total phenolic and total flavonoid) and antioxidant activities (DPPH and FRAP) were analyzed in strawberry. Quantitative analysis of conjugated flavonoid contents were obtained after different hydrolysis concentration and reaction period . The highest yields of myricetin and quercetin were found with 1.0M HCl and a reaction period of 0.5 hr, however , for kaempferol was 1.0M HCl and a reaction period of 1hr , respectively. In the study, we also estimated the correlation coefficient of TPC, TFC, DPPH and FRAP. In addition , a positive correlation was observed ( r = 0.980, P < 0.05) between TPC and TFC, TPC and TFC are correlated to the DPPH activity (r = 0.913, P < 0.05 and r = 0.899 , P < 0.05 , respectively) , and to the FRAP activity ( r = 0.958, P < 0.05 and r = 0.936, P < 0.05, respectively), respectively. These results pointed out that strawberry generally possesses a high level of antioxidant activities, which could be linked to the levels of phenolic compounds in the fruit.