H2 15O translocation in rice was enhanced by 10 μm 5-aminolevulinic acid as monitored by positron emitting tracer imaging system (PETIS)

5-Aminolevulinic acid (ALA) acts to increase chlorophyll biosynthesis, photosynthesis, cold stress tolerance, and salt tolerance at low concentrations. We studied the effects of ALA on H₂ ¹⁵O translocation from the roots to the shoots of rice plants (Oryza sativa L. cv. Nipponbare) in real time by a positron-emitting tracer imaging system (PETIS). When the plant was treated with 10 μm ALA, the velocity of the H₂ ¹⁵O translocation from 2 to 12 min after absorption increased to 126, 137, 140% that of the control at 1.5, 2.5, and 3.5 h after ALA treatment, respectively. However, ALA did not affect the H₂ ¹⁵O translocation within 0.5 h of treatment. When the plant was treated with 0.1 mM ABA at 4 h after 10 μm ALA treatment, the velocity of the H₂ ¹⁵O translocation decreased at 0.5 h after ABA treatment. Those observations suggested ALA might be absorbed and transported to the guard cells within 1.5 h and functioned to expand the stomatal aperture.     

Determination of the rate of 18F-labeled water movement to the leaf and its association with water relations in acid soil-tolerant rice varieties

The visual symptoms of damage by acid sulfate soil look quite similar to those due to soil moisture deficit. The present paper is to confirm if acid soil-tolerance is associated with drought tolerance in terms of leaf water potential, transpiration, and dry matter production. Seedlings of seven acid soil-tolerant (acid-tolerant), and three acid soil-intolerant varieties (acid-intolerant) were subjected to low pH conditions (pH 3.8) for 48 hours. The rate of water uptake was determined continuously by measuring radioactivity in the collar part (target area) of rice leaves exposed to ¹⁸F-labeled water (¹⁸F-water) using a Positron Emitting Tracer Imaging System (PETIS). The PETIS measurement showed that the radioactivity in the target position of leaves of acid-tolerant varieties increased faster than that of the intolerant varieties after the ¹⁸F-water was applied into the vial. In the plants subjected to low pH conditions, the transpiration rate (Tr) and leaf water potential (Ψ) decreased in both acid-tolerant and intolerant varieties. However, the extent of reduction was less in the acid-tolerant varieties than in the intolerant ones. Moreover, the dry matter production rate of the acid-tolerant varieties was significantly higher than that of the acid-intolerant ones in the low pH conditions. This study clearly shows that ¹⁸F-water uptake in a leaf was higher, and water relations were also better maintained in the acid-tolerant varieties compared with intolerant ones, resulting in higher growth rate in the acid-tolerant varieties, when plants were exposed to the acid solution conditions. We conclude that acid soil-tolerance is closely associated with leaf water relations in rice plants.     

稻鸭共生对鸭肉品质和屠宰性能的影响

以云南麻鸭为试验材料,分别在稻鸭共生(稻鸭组)和常规网上平养(常规组)两种饲养模式下饲养至体重达1.8 kg,测定其常规肉品质和部分屠宰性能.结果表明:①两组间鸭肉失水率、嫩度、熟肉率、肉色亮度值和红度值无显著差异(P＞0.05);稻鸭组的pH值显著高于常规组(P＜0.05);肉色黄度值B极显著高于常规组(P＜0.01).②两组间屠宰率、半净膛率、全净膛率、胸肉率差异不显著(P＞0.05);稻鸭组的皮脂厚、腹脂率比常规组分别降低了18.52%、11.76%(P＜0.05);腿肉率提高了11.40%(P＜0.05).③稻鸭组的生长速度明显慢于常规组.     

Experimental infection of enterotoxemic Escherichia coli associated with porcine edema disease and its pathologic characteristics in the intestine

Edema disease (ED) has become frequent in Japan, but no effective method for experimental infection has been developed. We report here the use of a capsule that resistant against gastric digestion to induce the ED in piglets. Four 21-day-old piglets were used. Shiga toxin 2e-producing Escherichia coli (STEC) cell pellet was encapsulated and administered orally. Two pigs received 1.0x10(10) CFU for two days, and the others received 3.9x10(8) CFU for three days. The high-dose group caused the typical clinical ED signs (palpebral edema or neurologic impairment). Eosinophil infiltration, swollen lymphoid follicles, and edema were observed in the ileum. The kidney had the thrombus in the glomerulus.     

Genetic characteristics of Japanese Holstein cows based on multiple-lactation random regression test-day animal models

The first three lactation curves of the Japanese Holstein cows were analyzed using a random regression (RR) test-day model with a cubic Legendre polynomial fitted to each of the three parities. The first three eigenvectors of the additive genetic RR covariance matrix explained 77.8, 10.9, and 4.2% of the total variance of the three parities and are associated mainly with the level of milk yield, the linear increase, and the concave curve, respectively. On a lactational basis, as the parity increases, the contribution of the first eigenvector to a lactational variation decreases whereas the contribution of the second eigenvector increases sharply. This means that the impact of the first eigenvector on the level of milk production decreases across parity whereas the effect of the second eigenvector on the shape of the lactation curve increases across parity. The first lactation curve was the most persistent, followed by the second and the third lactation. Persistency and days to reach peak yield decrease as the parity increases (45, 40, and 36 days for the first three parities). Daily heritabilities within lactation were lower for the first parity than for the second or the third parity. The first three lactation curves possess distinctive genetic characteristics that merit consideration when combining the proofs of the first three lactations to select for lifetime production. Within- and between-parity genetic correlations between the constant and the linear RR coefficients were all positive, suggesting that raising the level of milk production in one parity would increase the linear slope in all parities, thus improving persistency. Within- and between-parity genetic correlations between the constant and the quadratic RR coefficients were all negative, implying that increasing the level of production in one parity would deepen and/or widen the concave curve in all parities, thus decreasing persistency. The linear and quadratic RR coefficients were negatively correlated within or between parities and thus have antagonistic effects on persistency.     

Decreasing traits of fecal immunoglobulin A in neonatal and weaning piglets

The concentration of fecal secretory immunoglobulin A (sIgA) in neonate and weaning piglets was measured daily from 1 day after birth to 50 days of age. The concentration of fecal sIgA started from the level of 10(4) microg/g wet feces 1 day after birth and then increased to a maximal value of up to 10(5) microg/g within a few days of birth. The values constantly declined to between 10(1) and 10(2) microg/g for the next 10 days and were relatively constant until weaning. The level of sIgA in the feces remained very low until at least 50 days of age. The vulnerability of pre- or post-weaning piglets can be explained, at least in part, by this low level of sIgA in the intestine.     

Birth of normal offspring from mouse eggs activated by a phospholipase Czeta protein lacking three EF-hand domains

Sperm-specific phospholipase C, PLCzeta, is a candidate for the Ca(2+) oscillation-inducing factor that is introduced into the ooplasm upon sperm-egg fusion. In addition to the 647-residue full-length PLCzeta, s-PLCzeta lacking the N-terminal 110 amino acids is known to be present in the mouse testis. In this study, we attempted to obtain full-term offspring from s-PLCzeta-activated eggs by round spermatid injection. Metaphase II-arrested eggs injected with a high RNA concentration of s-PLCzeta RNA normally developed to blastocysts. When the round spermatid nucleus was injected into telophase II-stage eggs previously activated by s-PLCzeta RNA, three live offspring were successfully obtained by transfer of the developed 4-cell embryos to pseudopregnant mice. These three offspring all grew to be normal adults and reproduced healthy second-generation mice.