Comparison of the response to phosphorus deficiency in two lupin species,Lupinus albus and L. angustifolius,with contrasting root morphology

White lupin (Lupinus albus) produces cluster roots, an adaptation to low soil phosphorus (P). Cluster roots exude large levels of P‐solubilizing compounds such as citrate and malate. In contrast, narrow leaf lupin (L. angustifolius) is closely related to L. albus, but does not produce cluster roots. To examine the different strategies for P acquisition, we compared the growth, biomass allocation, respiratory properties and construction cost between L. albus and L. angustifolius under P‐deficient conditions. Both Lupinus species were grown in hydroponic culture with 1 or 100 μM P. Under the P‐deficient regime, L. albus produced cluster roots with little change in biomass allocation, while L. angustifolius significantly increased biomass allocation to roots. The rate of cyanide‐resistant SHAM (salicylhydroxamic acid)‐sensitive respiration was high in cluster roots and very low in roots of L. angustifolius. These results suggest a low alternative oxidase (AOX) activity in L. angustifolius roots, and thus, ATP would be produced efficiently in L. angustifolius roots. The construction cost was highest in cluster roots and lowest in L. angustifolius roots. This study shows that under P deficiency, L. albus produces high‐cost cluster roots to increase the P availability, while L. angustifolius produces large quantities of low‐cost roots to enhance P uptake.     

On artifacts appearing in the histochemical fixation of glycogen

1. Fixation artifacts associated with glycogen translocation are prevalent in tissues of parenchymatous type and scarce or non-existent in tissues of loose type. 2. Liver tissue treated with M/3 NaOH solution before fixation did not show an uneven distribution of glycogen. This was interpreted as indicating that the liver, a tissue of parenchymatous type, was changed, so to speak, into a loose type of tissue by alkali treatment. 3. The so called Alkohol-flucht of glycogen was produced in Yoshida's ascites tumor cells by a procedure which changed a loose type of tissue into a parenchymatous one, that is, by packing the tumor cells tightly. 4. The translocation of glycogen in cells appeared to occur when the fixatives penetrated the cells rapidly from a single direction, but failed to occur when the cells were attacked by the fixative from all directions. 5. In dried smears of Yoshida's ascites tumor cells and bone marrow cells, the glycogen particles are translocated to the peripheral regions of the cells, and coalesce there. The production of these artifacts is related in some way to the physicochemical properties of the protoplasm and plasma membrane of the cells.     

The possibility of photo-induced induction of nitrate reductase in rice seedlings

Nitrate reductase activity in rice seedlings showed daily fluctuations.Seedlings placed in the dark slowly lost activity and quicklyregained it when exposed to sunlight. Etiolated seedlings alsoshowed rapid increases in activity when transferred to sunlight.This increase in activity by sunlight was inhibited by bothchloramphenicol and ethionine. Ethionine inhibition was reversedby methionine. Purification of nitrate reductase was carriedout by ammonium sulfate fractionation and DEAE-cellulose columnchromatography. Nitrate reductase was purified about 40-foldfrom plants placed in the dark and in sunlight. Incorporationof mediionine-S-¹⁴CH₃ into the nitrate reductase fraction wasstudied. In sunlight, the specific radioactivity of the nitratereductase fraction from the DEAE-cellulose column increased2-fold as compared with that of the crude extracts. Specificradioactivity did not increase in the dark. ¹Present address: Asahi Kasei Chemicals Industry Co., Ltd.,Sameshima 2-1, Fuji, Shizuoka, Japan (Received December 3, 1968; )     

Timing of emergence of males and females of Ephoron shigae (Ephemeroptera: Polymitarcyidae)

SUMMARY. 1. The winged adults of Ephoron shigae swarming over the water surface were collected by successive random sweeps during their daily emergence period, and the changes in sex and stage composition were examined, in the lower reach of the Asahi River in western Japan.
2. The emergence occurred mainly during a 1¹/₂ h period beginning some time after sunset. Male sub-imagos emerged synchronously and moulted to imagos in a 25 min period immediately prior to an abrupt increase of female emergence.
3. This timing of male emergence may be considered the result of selection of males to decrease the risk of death before mating, and for all the males to have an equal opportunity to mate.     

Studies on chlorophyllase of Chlorella protothecoides II. Formation of atypical chlorophyllide a

When chlorophyll a was incubated with a preparation of chlorophyllaseextracted with Triton X-100 from methanol-acetone powder ofChlorella protothecoides, the substrate was changed to chlorophyllidea, and subsequently to an atypical form of chlorophyllide a.The formation of an atypical form of chlorophyllide was notdetected in the reaction with chlorophyll b as substrate, norin the reaction with another preparation of chlorophyllase extractedfrom the algal cells. (Received August 18, 1969; )     

Induction of the Acrosome Reaction in Starfish

In the starfish, Asterias amurensis , at least two distinct components of the egg jelly are required for inducing the acrosome reaction: a sulfated glycoprotein named acrosome reaction-inducing substance (ARIS) and a diffusible organic substance(s) named Co-ARIS. The following evidence suggested that ARIS and Co-ARIS cooperatively activate CA-channels of the sperm plasma membrane and eventually induce dramatic changes in sperm morphology, the acrosome reaction. 1) Pronase digest of ARIS (P-ARIS) and Co-ARIS, either as a pure or a crude preparation (Fraction M₈), were fully effective in combination for induction of the acrosome reaction in normal sea water, although they were not effective individually. P- ARIS alone induced the acrosome reaction fully in high Ca²⁺ sea water and markedly at high pHs, whereas Fraction M₈ alone did not induce the reaction even in these conditions. The reaction was not induced by increase in either the Ca²⁺ concentration or the pH of sea water, but was markedly induced in the absence of jelly components by raising both the pH and Ca²⁺ concentration together. 2) The ionophore A23187 induced the acrosome reaction appreciably when present alone and fully in the presence of monensin or Fraction M₈. Monesin alone was ineffective. 3) The jelly or a combination of ARIS and Fraction M₈ caused abrupt Ca²⁺ -uptake by the sperm. The Ca-channel blockers verapamil and diltiazem inhibited the jelly-induced acrosome reaction.     

Maitotoxin, A Presumed Calcium Channel Activator, Induces the Acrosome Reaction in Mussel Spermatozoa

Maitotoxin, a presumed activator of the voltage-sensitive calcium channel, induced the acrosome reaction in the mussel, Mytilus edulis at physiological pH and in the starfish, Asterias amurensis at pH 9.5. The induction of acrosome reaction by maitotoxin depended upon external Ca²⁺ and was inhibited by two types of calcium channel blockers; verapamil and diltiazem. These results suggest that the activation of the voltage-sensitive calcium channel takes an important part in the initiation of acrosome reaction in Mytilus and other animals.