外源抗坏血酸对烟草细胞生长及衰老的影响

用不同浓度的外源抗坏血酸(ASA)对BY-2烟草悬浮细胞进行处理,测定了细胞中可溶性蛋白质含量、脂质过氧化产物丙二醛(MDA)含量、相对电解质渗透率、超氧化物歧化酶(SOD)活性、抗坏血酸(ASA)含量和还原型谷胱甘肽(GSH)含量等生理生化指标,从细胞脂质过氧化及抗氧化功能的角度探讨了不同浓度抗坏血酸对BY-2烟草悬浮细胞生长及衰老的影响。结果表明,当用2mmol.L-1 ASA处理时,能促进细胞分裂生长,增加可溶性蛋白产量,减少膜透性和MDA含量,维持SOD活性和ASA与GSH含量在较高水平,说明ASA对促进细胞生长,维持细胞抗氧化功能以延缓细胞衰老方面起着重要作用。但当ASA浓度过高,超出4mmol.L-1时则对细胞造成伤害,MDA含量和膜透性增加,SOD活性降低,ASA和GSH含量呈现先升后降的趋势。     

巨胚杂交稻的农艺及产量性状

以2个巨胚不育系及其相应的2个非巨胚不育系,3个巨胚恢复系、2个非巨胚恢复系为材料,配制一套共20个半双列杂交组合,研究巨胚(ge)基因对杂交稻的若干生物学特性的影响。结果表明:ge基因对杂交稻主要农艺性状和部分产量性状没有显著影响,但ge基因使杂交稻的千粒重、容重、理论产量和实际产量下降,且只有在纯合时才有显著表达。含杂合geGE基因也使其上述性状有所下降,但幅度明显小于gege纯合基因。     

利用菜青虫细胞检测几种有机溶剂和有机磷农药的毒力

用MTT法研究了5种有机溶剂对菜青虫细胞生长的影响及3种有机磷农药对细胞的毒力。并用微量点滴法测定了3种农药对菜青虫3龄幼虫的毒力。结果表明,5种有机溶剂除二甲苯外,其余4种二甲亚砜、乙醇、丙酮、乙酸乙酯对菜青虫细胞低浓度处理时均无很大毒性。1％浓度处理16小时后细胞存活率仍分别可达99.8％、98％、97.2％、91％。分别用菜青虫细胞测得3种有机磷农药的LC_(50)为:甲基对硫磷,106μs/ml;克线磷,147μg/ml;水胺硫磷,183μg/ml。用微量点滴法测得3种有机磷农药对菜青虫3龄幼虫的LD_(50)分别为:甲基对硫磷,0.458μg/头,克线磷,45.012μg/头;水胺硫磷,0.505μg/头。     

温湿度调控对番茄灰霉病菌产生的细胞壁降解酶的影响

 番茄灰霉病菌在致病过程中能够产生4种细胞壁降解酶,以PMG酶活性最高,其次是β-葡萄糖苷酶和PG酶,Cx最少。灰霉病菌在不同温度下侵染番茄叶片时产生的致病酶活性不同,4种酶在20℃时表现了最高的活性,15℃次之,当温度达到25℃时,各种酶的活性都急剧下降,随着温度的再升高,酶活更低。随着湿度的增高,病菌产生的细胞壁降解酶的活性也增加,当相对湿度达到90%以上时,4种酶的活性也达到最高。温湿度对番茄灰霉病菌产生细胞壁降解酶的影响趋势,与其对发病的影响趋势是一致的。     

龙眼花粉母细胞减数分裂观察

以龙眼石硖品种为材料,采用改良涂片法对花粉母细胞减数分裂过程进行了系统观察。结果表明,（1）龙眼减数分裂进程与花蕾大小,花药颜色有密切关系,在同一花蕾甚至同一花药中表现不同步性。（2）龙眼减数分裂染色体行为存在染色体片段、落后染色体、染色体桥、分裂不同步、微核及多分体等异常现象,从细胞遗传学水平上分析了龙眼花粉母细胞减...     

Expression of natural killer cell stimulatory receptor NKG2D and its ligand MICA in Tibetan patients with gastric cancer at Qinghai plateau

AIM: To investigate the expression of natural killer cell stimulation receptor D(NKG2D) in peripheral blood and the expression of major histocompatibility complex class I chain-related protein A(MICA) on the gastric carcinoma tissue and the neighboring non-cancerous tissue in Tibetan patients with gastric cancer at Qinghai plateau. METHODS: Samples of 33 patients and 20 healthy persons were collected to detect NKG2D in peripheral blood by Flow cytometry analysis. The expressions of MICA in part of the correspondent tissues were examined by RT-PCR and immunohistochemistry.RESULTS: The expression of NKG2D in the plateau of Tibetan patients with gastric cancer group (13.47 ±5.26)% was significantly lower than that in healthy groups (32.62±10.08)%. The mRNA level of MICA in gastric cancer was significantly higher than that in neighboring non-cancerous tissue (P<0.05). The expressions of MICA proteins showed a significant difference between the neighboring non-cancerous tissue (21.21%, 7/33) and the gastric carcinoma tissue (78.79%, 26/33), between the high differentiation (60.00%, 3/5) and the moderate (72.73%, 8/11), low differentiation (88.24%, 15/17). The expressions of MICA were not correlated with tumor size, sex, age, lymph node metastasis of the patients (P>0.05). Spearman rank correlation displayed that the expressions of MICA mRNA were positively correlated with the MICA protein level (r=0.903, P<0.01).CONCLUSION: The immune escape in Tibetan patients with gastric cancer at Qinghai plateau probably relates to the down-regulation of NKG2D and the up-regulation of its ligand MICA. The activity of NK cells and the anti-cancer cellular immunity level are descending in the plateau of Tibetan patients with gastric cancer. The decrease in the receptor NKG2D is a reason for the activity of NK cell descending.     

A New Cell Wall Located N-rich Protein is Strongly Induced During the Hypersensitive Response in Glycine Max L.

Soybean (Glycine max (L.) Merill, cv. Williams 82) plants and cell cultures respond to avirulent pathogens with a hypersensitive reaction. After inoculation of soybean with Pseudomonas syringae pv. glycinea, carrying the avirulence gene avrA, or zoospores from the fungus Phytophthora sojae Race 1, a resistance-gene-dependent cell death programme is activated. A new gene was identified by differential display of mRNAs that is specifically activated during the early phase of incompatible pathogen-soybean interactions but does not respond to compatible pathogens. The gene is strongly induced within 2h after addition of P. sojae zoospores. A similar kinetic pattern was observed for P. syringae (avrA) inoculated soybean cell cultures. The gene encodes a deduced protein of 368 amino acids with a very high content of asparagine and was therefore termed N-rich protein (NRP). The protein is composed of two distinct domains, of which only the C-terminal domain has striking homology to proteins of unknown function from other plants. An antibody raised against the recombinant NRP recognizes a protein of 42kDa. The protein is located in the cell wall as indicated by cell fractionation studies. Comparison of the genomic DNA-sequence with the cDNA, identified two introns within the open reading frame. The NRP-gene is not directly induced by salicylic acid or hydrogen peroxide, indicating a distinct and specific signal transduction pathway which is only activated during programmed cell death. The NRP-gene appears to be a new marker in soybean activated early in plant disease resistance.     

不同发育时期板栗叶肉细胞中叶绿体淀粉和质体小球的变化

对板栗在春季折叠的幼叶和平展生长的幼叶、夏季成熟叶和秋季老叶的叶肉细胞中的叶绿体做了透射电镜观察,结果表明,春季折叠的幼叶的叶绿体中不含淀粉和质体小球,平展生长的幼叶含淀粉粒没有质体小球;夏季成熟叶的叶绿体中淀粉最多并出现极少量质体小球;秋季衰老叶的叶绿体中淀粉粒减少直至消失,质体小球数量激增;有的质体小球在叶绿体内被一层膜包围并降解。根据染色特点,可将质体小球分为黑色和灰色2类。淀粉减少及质体小球增多与叶绿体功能衰退相关。     

麦冬水提物对猫肾细胞的影响研究

麦冬是我国传统中药之一,兼备保健和治疗作用。为了探究麦冬能否应用在宠物食品中,本试验以不同浓度的麦冬水提物(3.91 ～8000 μg/mL)为受试药物,从细胞的形态、增殖、凋亡及周期4个方面对猫肾细胞(F81)进行安全性评价。结果表明：在试验浓度范围内,麦冬水提物没有抑制F81的增殖,且在3.91～62.5 μg/mL的浓度范围内,凋亡及周期结果经统计学分析均无显著性差异,与对照组接近,且细胞形态良好。说明在一定浓度范围内,麦冬水提物对F81细胞无毒害作用。     

Therapeutic Potential of Marine Peptides in Prostate Cancer: Mechanistic Insights

Prostate cancer (PCa) is the leading cause of cancer death in men, and its treatment is commonly associated with severe adverse effects. Thus, new treatment modalities are required. In this context, natural compounds have been widely explored for their anti-PCa properties. Aquatic organisms contain numerous potential medications. Anticancer peptides are less toxic to normal cells and provide an efficacious treatment approach via multiple mechanisms, including altered cell viability, apoptosis, cell migration/invasion, suppression of angiogenesis and microtubule balance disturbances. This review sheds light on marine peptides as efficacious and safe therapeutic agents for PCa.