Effect of Ionizing Radiations on Rice

Rice seed and natural brown rice were irradiated with cobalt-60 gamma rays and cathode rays. Development of primary leaf and root was highly inhibited by irradiation more than 5×l0⁴ rep, whereas the growth of root was somewhat accelerated by 5×10³ rep. More than 1.6×l0⁶ rep was necessary for the complete destruction of the germination. Thiamine and riboflavin contents of rice seed irradiated with 10⁵ rep of cobalt-60 gamma rays were almost the same magnitude as the non-irradiated one, and 87 to 96% of microorganism on brown rice could be killed with 1×l0⁵ rep.     

Effects of Autogamy In Paramecium Tetraurelia On Catalase Activity and On Radiosensitivity to Natural Ionizing Radiations

SYNOPSIS Catalase activity of Paramecium tetraurelia decreased during autogamy and recovered to normal 5 days later. Autogamy also caused changes in the ciliate's sensitivity to natural ionizing radiations—the decrease in cell growth rate previously described in shielded cultures did not occur when autogamous cells were used. Maximum effect of shielding was observed in 11-day-old postautogamous cells. the role of the catalase in the mechanism of natural irradiation effect is discussed.     

激光及γ射线对有丝分裂染色体畸变感应现象的比较

波长514nm的激光照射可用于研究激光导致有丝分裂染色体畸变的效应。本文提供了一种新的辐照系统,能用于研究突变的感应现象,并与从γ-线辐射源获得的结果进行了比较。 Abstract:Laser irradiation at wavelength 514 nm was used to study the effect of lasers in inducing chromosomal aberrations at mitosis.This study offers a new radiation system which could be used for the induction of mutations.Results are compared with those obtained from studies using γ-rays as irradiation source.     

Enhancement of the Over-all Lethal Effect of Ionizing Radiations on Microorganisms by Sodium Chloride

Aiming at the enhancement of total lethal effect of radiations, chemical agent actions on irradiated cells were investigated. It was found that the sensitivity of irradiated cells to NaCl was markedly increased by radiation. In other words, the over-all lethal effect of radiations on microorganisms was enhanced by the pre- or post-treatment with NaCl. Some microbiological aspects of radiation enhancement of NaCl sensitivity were described in this paper, connecting with the possible mechanism. The fact that this phenomenon of radiation enhancement was observed in the case of the cells which gave the one-hit type survival curve suggests that radiation damage responsible for this phenomenon is not restricted to biological targets. Further discussion and experimental evidences will be presented in the subsequent paper.     

氮肥运筹对不同种植方式冬小麦群体结构及产量的影响

以山西农业大学培育的多穗型冬小麦山农9801为供试材料,采用随机区组的方法,在施氮总量每公顷300 kg时,分别对常规条播(B1)和窄行稀条播(B2)实施不同氮肥基追比:CK(10∶0)、C1(7∶3)、C2(5∶5)、C3(3∶7),研究其对拔节期小麦群体形态、各生育期叶面积指数及总茎数、产量构成因素的影响。结果表明:窄行稀条播促进了冬小麦群体生长,提高了实际产量。不同氮肥运筹对两种播种方式小麦生长及产量的影响很大,拔节期追施氮肥后小麦各指标均在C1、C2较高,整体看C1最高,且对窄行条播的提高作用更为明显。B2种植基追比7∶3时,旗叶面积、株高、次生根数最多,黄叶数最少,且与其他处理达到显著差异,拔节期到孕穗期LAI最高,群体总茎数及单株成穗数最大,C1处理通过显著增加有效穗数、穗粒数及千粒重来增加实际产量。上述分析结果为晋中窄行条播冬小麦氮肥合理利用,优质高产提供了实验和理论依据。     

氮源和碳源对解淀粉芽孢杆菌Q-426抗菌脂肽合成的影响

微生物来源的环状脂肽在生物农药以及医学领域极具应用潜力。通过测量抑菌活性并利用反相高效液相色谱(RP-HPLC),液相质谱联用(HPLC-MS)和串联质谱(MS/MS)技术检测抗菌脂肽组分的变化研究了氮(N)源、碳(C)源和培养基中的初始pH值对解淀粉芽孢杆菌Q-426菌株中抗菌脂肽bacillomycin D和fengycins合成的影响,从而为进一步研究它们生物合成的基因调控以及更有目的性提高产量提供理论依据。结果表明:L-组氨酸、L-赖氨酸、甘油、山梨醇以及培养基中的[OH]-均能促进脂肽bacillomycin D的合成,但它们在该实验菌株抗菌脂肽bacillomycinD合成途径中的调控靶点有所不同。     

LH and hCG Action on the Same Receptor Results in Quantitatively and Qualitatively Different Intracellular Signalling

Human luteinizing hormone (hLH) and chorionic gonadotropin (hCG) act on the same receptor (LHCGR) but it is not known whether they elicit the same cellular and molecular response. This study compares for the first time the activation of cell-signalling pathways and gene expression in response to hLH and hCG. Using recombinant hLH and recombinant hCG we evaluated the kinetics of cAMP production in COS-7 and hGL5 cells permanently expressing LHCGR (COS-7/LHCGR, hGL5/LHCGR), as well as cAMP, ERK1/2, AKT activation and progesterone production in primary human granulosa cells (hGLC). The expression of selected target genes was measured in the presence or absence of ERK- or AKT-pathways inhibitors. In COS-7/LHCGR cells, hCG is 5-fold more potent than hLH (cAMP ED₅₀: 107.1±14.3 pM and 530.0±51.2 pM, respectively). hLH maximal effect was significantly faster (10 minutes by hLH; 1 hour by hCG). In hGLC continuous exposure to equipotent doses of gonadotropins up to 36 hours revealed that intracellular cAMP production is oscillating and significantly higher by hCG versus hLH. Conversely, phospho-ERK1/2 and -AKT activation was more potent and sustained by hLH versus hCG. ERK1/2 and AKT inhibition removed the inhibitory effect on NRG1 (neuregulin) expression by hLH but not by hCG; ERK1/2 inhibition significantly increased hLH- but not hCG-stimulated CYP19A1 (aromatase) expression. We conclude that: i) hCG is more potent on cAMP production, while hLH is more potent on ERK and AKT activation; ii) hGLC respond to equipotent, constant hLH or hCG stimulation with a fluctuating cAMP production and progressive progesterone secretion; and iii) the expression of hLH and hCG target genes partly involves the activation of different pathways depending on the ligand. Therefore, the LHCGR is able to differentiate the activity of hLH and hCG.     

非诱变剂对姐妹染色单体交换的诱导效应

检测了16种非诱变剂对大麦根端分生细胞姐妹染色单体交换(SCE)的影响及其中9种成份对人外周血淋巴细胞SCE的影响。在大麦细胞中,用高浓度的葡萄糖、氯化钠、维生素、氨基酸及脱氧核糖核苷三磷酸(dNTP)处理均能显著提高SCE频率。维生素、氨基酸和dNTP对人外周血淋巴细胞中的SCE频率也有显著影响。实验结果表明,不只是诱变剂能提高SCE频率,非诱变剂在一定高剂量时也能提高SCE频率。非诱变剂影响SCE具有特殊的S CE增长曲线,SCE频率达一定值后不再随处理浓度的增大而提高。