変化する塩ストレス条件下における湛水の電気伝導度とイネの乾物生産低下の関係

　Knowledge about the relationships between the intensity of salinity of rooting medium and dry matter production may contribute to the improvement of rice yield under saline conditions. A rice cultivar Koshihikari was grown in pots with soils under submerged soil conditions. The stagnant water was salinized with NaCl from 31, 45 and 59 days after sowing, and for each of those, the level of salinity was increased every 6 days to maturity at three different rates of increase. Electrical conductivity (EC) of stagnant water was measured. Final dry weight of above ground parts and panicles decreased as initiation of salinization took place earlier and the rate of increase of EC was higher. Reduction in panicle dry weight was correlated with the occurrence of white heads. The values of EC at which plants died increased with the plant development and the rate of increase of EC, while these depended mainly on the rate of increase of EC but not on the time of salinization. In the plants which survived after heading, the final dry weight decreased in proportion to accumulated EC (sum of EC values for each day until harvest). Therefore, except for strong salinity where plants may die before heading, accumulated EC should be abe to predict dry matter production under salinity as an integrated indicator of level and duration of salinity.塩性環境における稲作改善のために，イネの乾物生産と根域の塩性程度との関係を知ることは重要である．水稲品種コシヒカリを用い，土壌を詰めたポットで湛水栽培し，湛水に塩化ナトリウム（塩）を添加することによって塩ストレスを与えた．塩添加は播種後31，45および59日目から開始され，それぞれ６日ごとに３段階の異なる速度で塩を添加するとともに，湛水の電気伝導度（EC）を測定した．地上部および穂の最終的な乾物重は，塩添加開始が早いほど，EC の増加速度が大であるほど低下した．そして，穂の乾物重は白穂の発生率が高いほど低下した．植物体が枯死したときの EC 値もまた，塩添加の開始時期が早いほど速度が大であるほど大きかったが，この EC 値は主にEC 増加速度に依存しており，塩添加開始時期の影響は小さかった．一方，出穂した植物で乾物重は積算 EC 値（毎日の EC の値を植物体採取日まで足した値）に対して直線的に低下した．以上より，出穂する前に枯死するような強い塩性環境を除けば，積算 EC 値は塩ストレスの強さと期間を総合した指標で，イネの最終的な乾物生産をよく予測すると考えられた

Previous residences and characteristics of residents in a retirement home in Onjuku town, Chiba prefecture

This paper intends to consider the elderly migration to retirement homes for the elderly (Yuryo-Rojin-Homu in Japanese) as a case study in Onjuku in Chiba prefecture. To achive this purpose, the attributes of 286 residents and their previous residences are analyzed based on the directory of residents. As the resultes, the attributes of residents are mostly uniform. Most of them moved independently at ages of 60s from central area of the Tokyo Metropolitan Area (Tokyo, Yokohama, Kawaswaki), and their moves were done by themselves or with spouses. As to their social-economic statuses, their previous occupations and educational status are very high. The intensions of their movements are not to enjoy their life after the retirement at the facility. For residents, most significant function of the private home is the nursing care that is secured until they die, namely "lifelong care". Their movements are not the "amenity move". It is obvious that the private home residents move to receive the "lifelong care"

Changes of Rice Sodium Content due to Sodium Exclusion and Transpiration under Salinity

The relationship between sodium contents of tops and transpiration rates was studied in two rice varieties with different sodium exclusion rates in roots; Kala-Rata1-24(KR1;low exclusion rate) and IR28 (high exclusion rate). Seedlings at 7th leaf stage grown in culture solution were subjected to saline water(100mM sodium chloride) and transpired for 12 hours. Various transpiration rates were obtained under different humidity, light intensity and temperature conditions. Transpiration stream concentration factor of Na+ (TSCFNa+), which denotes the sodium exclusion rate in the root, decreased with increase in the transpiration rate under different humidity and light intensity conditions. On the other hand, TSCFNa+ was lower in KR1 than in IR28 under different temperature conditions. There were no different in the sodium exclusion rates at high transpiration rates. Sodium contents of tops initially increased with the transpiration rates but afterwards decreased with the transpiration rates. Sodium contents of tops were higher in KR1 than in IR28 at low transpiration rates under high humidity and low light intensity conditions, but it was higher in IR28 under low temperature conditions. There were no varietal differences in the sodium contents of tops at high transpiration rates. These results indicated that the varietal differences in sodium exclusion rates were detectable at low transpiration rates and affected the sodium contents of tops, but there were no differences in the sodium contents of tops at high transpiration rates.イネでは、ナトリウム（Na)含有率が高いほど光合成速度、苗の生存率および相対生長速度が低下することから、塩ストレス下における体内Na含有率の品種間差異に着目した研究が進められてきた。しかし、塩ストレスに対する体内Na含有率の品種による反応は、研究によって異なる。Makiharaらは、幼苗期にNa含有率が異なるとされる品種を成熟まで栽培したところ、Na含有率に大きな差異を見出さなかった。また、Makiharaらの研究でNa含有率が低かった品種が、森田らの研究では高かった。イネは、根においてナトリウムイオン（Na+）を分離排除する能力をもし、その程度は品種によって異なる。この能力は体内に入り込む水のNa+濃度に影響を与えるのが、体内に取り込まれるNa+の質は、流れる水の総量に影響される。すなわち、イネのNa含有率は、蒸散量と蒸散流に含まれるNa+濃度によって決まり、後者は根におけるNa+排除率によって変わる。蒸散と排除率はいずれも環境条件によって変わると考えられ、それによって体内Na含有率も変わるであろう。したがって、研究によってNa含有率の反応が異なるのは、両者の相互作用によると考えられえる。しかし、蒸散量とNa+排除率の変化が体内Na含有率にどのように影響を与えるのかは知られていないので、本研究で調べた

Production of a Transgenic Mosquito Expressing Circumsporozoite Protein, a Malarial Protein, in the Salivary Gland of Anopheles stephensi (Diptera:Culicidae)

We are producing a transgenic mosquito, a flying syringe, to deliver a vaccine protein to human beings via the saliva the mosquito deposits in the skin while biting. The mosquito produces a vaccine protein in the salivary gland (SG) and deposits the protein into the host's skin when it takes the host's blood. We chose circumsporozoite protein (CSP), currently the most promising malaria vaccine candidate, to be expressed in the SG of Anopheles stephensi. To transform the mosquitoes, plasmid containing the CSP gene under the promoter of female SG-specific gene, as well as the green fluorescent protein (GFP) gene under the promoter of 3xP3 as a selection marker in the eyes, was injected into more than 400 eggs. As a result, five strains of GFP-expressing mosquitoes were established, and successful CSP expression in the SG was confirmed in one strain. The estimated amount of CSP in the SG of the strain was 40ng per mosquito. We allowed the CSP-expressing mosquitoes to feed on mice to induce the production of anti-CSP antibody. However, the mice did not develop anti-CSP antibody even after transgenic mosquitoes had bitten them several times. We consider that CSP in the SG was not secreted properly into the saliva. Further techniques and trials are required in order to realize vaccine-delivering mosquitoes

Growth and Sodium Accumulation in the Tillers which Appear on the Upper Nodes in Rice (Oryza sativca L.) Under Saline Conditions

The mechanism of late-grown tillers which come out of the upper culm nodes in rice (Oryza sativa L.) under saline conditions was examined. A rice cultivar, Akihikari was grown in pots under flooding conditions. The panicles were excised below the neck node of the panicle at the heading stage. Salinity treatment consisted of adding 100mM sodium chloride to water of pot at the excision of panicle (Na0), and 14 days after the excision (Na2). Tillers on the upper clum nodes grew in NaO and Na2. Dry weight of tillers increased with decrease of dry weight of stock shoots that produced the tillers. So the sum of dry weights of the stock shoots and tillers did not change, indicating that tiller growth apparently depended on reserve of carbohydrate in the stock shotts. Sodium was accumulated gradually in the plant, while sodium content of internode and tiller were kept lower than those of leaa blade and leaf sheath. In the leaf blade and leaf sheath, the upper organs accumulated less sodium than the lower organs. The tillers on the upper nodes grow faster and had low sodium content in the early stages of tiller development in NaO. Therefore, it was concluded that tillers which come out of the upper culm nodes could grow under saline conditions because the sodium content of tiller, internode and the upper leaf sheath were kept at a relatively low level.塩条件下において高節位分げつが成長する要因を調べた．水稲品種アキヒカリをポットに移植し湛水条件で栽培し，出穂期に穂を穂首節真下より切除した．ポットの水にNaCl濃度100mMとなるようにNaClを添加する処理を穂切除直後（Na０区）と14日後（Na２区）に行った．Na０とNa２区ともに高節位分げつが成長，乾物重が増加するとともに分げつを発生させた茎（母茎）の乾物重は低下した．分げつと母茎の乾物重の和は変化がなく，分げつの成長は母茎の貯蔵炭水化物によっていた．節間と分げつのNa含有率は葉身と葉より低く保たれ，葉身，葉鞘でも下位節に比べ上位節のNa含有率が低かった．またNa０区の分げつ成長初期では茎上部の分げつほど成長が早く，Na含有率が低かった．以上のことから塩条件下で高節位分げつが成長するのは分げつと乾物供給源である節間と上位葉のNa含有率が比較的低く抑えられるためであると考えられた

The Effect of Prevention of Root Injury on Growth, Development and Dry Weight in Rice (Oryza sativa L.) Transplanted to Saline Soil

Rice root has an important role in water absorption and exclusion of sodium ion in saline soil. However, it is injured during transplanting to paddy field. The objective of this study was to examine whether prevention of such root injury reduces salinity damage in rice. Extremely early rice cultivar "Akihikari" that is not salt tolerant was grown in plastic bags filled with soil. Roots of seedlings were clipped leaving 5mm~10mm, then transplanted to 5L pots filled with soil applied with 0g, 7g and 10g of sodium chloride (NaCl). The growth and dry weight at the mature stage was compared to those of plants transplanted with intact roots. Time of transplanting was 12, 19, 26 and 33 days after sowing. Increase of number of stems was suppressed due to root clipping and salinity, but there was no interaction between the two factors. Dry weight of total above ground part and panicle decreased due to salinity though root clipping did not change them. The reduction of panicle dry weight was caused by the reduction of mean number of spikelets per panicle, thus mean panicle dry weight, as number of panicles and mean spikelet dry weight showed no changes. It was concluded that prevention of the root injury may not effectively alleviate salinity damage in less salt tolerant rice cultivars.イネの根は吸水するとともにナトリウムイオンを排除する役割を持っている．水田移植栽培において根の損傷を防ぐことが効果的に塩害を軽減するかどうかを検討した．耐塩性の弱いイネ極早生品種アキヒカリを用い，土壌を詰めたビニール袋で育苗した．苗の根を5 ㎜～10 ㎜ 残し切除して，塩化ナトリウム（NaCl）0ｇ，7ｇ，10ｇを土壌に添加したポットに移植し，根を傷つけないように移植した植物と生育と成熟期の乾物重を比較した．移植は播種後12日，19日，26日，33日の4回行った．茎数の増加は根の切除および塩添加によって抑制されたが，二要因の交互作用はなかった．成熟期の地上部と穂の乾物重は塩添加によって減少したが，根切除の影響はなかった．穂の乾物重の減少は穂数と平均1籾重が変わらなかったため，平均1穂籾数の低下による平均1穂重の低下によっていた．以上の結果から耐塩性が小さい日本の品種において移植時の根の損傷を防ぐことは，塩害軽減に効果的でないと考えられた

The Functional Domain of GCS1-Based Gamete Fusion Resides in the Amino Terminus in Plant and Parasite Species

Fertilization is one of the most important processes in all organisms utilizing sexual reproduction. In a previous study, we succeeded in identifying a novel male gametic transmembrane protein GCS1 (GENERATIVE CELL SPECIFIC 1), also called HAP2 (HAPLESS 2) in the male-sterile Arabidopsis thaliana mutants, as a factor critical to gamete fusion in flowering plants. Interestingly, GCS1 is highly conserved among various eukaryotes covering plants, protists and invertebrates. Of these organisms, Chlamydomonas (green alga) and Plasmodium (malaria parasite) GCS1s similarly show male gametic expression and gamete fusion function. Since it is generally believed that protein factors controlling gamete fusion have rapidly evolved and different organisms utilize species-specific gamete fusion factors, GCS1 may be an ancient fertilization factor derived from the common ancestor of those organisms above. And therefore, its molecular structure and function are important to understanding the common molecular mechanics of eukaryotic fertilization. In this study, we tried to detect the central functional domain(s) of GCS1, using complementation assay of ArabidopsisGCS1 mutant lines expressing modified GCS1. As a result, the positively-charged C-terminal sequence of this protein is dispensable for gamete fusion, while the highly conserved N-terminal domain is critical to GCS1 function. In addition, in vitro fertilization assay of Plasmodium berghei (mouse malaria parasite) knock-in lines expressing partly truncated GCS1 showed similar results. Those findings above indicate that the extracellular N-terminus alone is sufficient for GCS1-based gamete fusion

The First Case of a Class I Glucose-6-phosphate Dehydrogenase Deficiency, G6PD Santiago de Cuba (1339 GA), in a Chinese Population as Found in a Survey for G6PD Deficiency in Northeastern and Central China

In Liaoning Province in northeastern China, we found a G6PD-deficient patient at the age of 3. By the classification of the World Health Organization, this patient was categorized as class I (very severe G6PD deficiency). When we investigated the G6PD gene of the patient, we found that he had a replacement of G to A at nucleotide 1339. As a result, the amino acid at position 447 should change from Gly to Arg. This replacement is known as G6PD Santiago de Cuba, because it was first discovered in a Cuban boy who showed heavy chronic anemia. Today, 28 G6PD variants have been reported in the Chinese population, and all are categorized as class II (severe deficiency) or class III (mild deficiency);in class II or III deficiency, anemia is not present in daily life, but hemolytic attack can occur when the carrier ingests certain oxidative medicines or foods. This is the first report of a G6PD-deficient Chinese patient in the category of class I. We intended to find other G6PD-deficient cases in northeastern China and tested several hundred blood samples, but no cases of G6PD deficiency were found (0/414). In central China, where falciparum malaria was endemic from the 1950s to 1970s, we found two G6PD-deficient cases (2/27) and the other members from their families whose variant type was G6PD Kaiping (1388GT), which is a common variant in the Chinese population.</p