现代农业科技园区创新发展模式探索研究

珠海市农业科学研究中心被命名为"国家农业高新科技示范园"、"广东省农业科技示范园"、"全国十大农业科技示范园",经过近10年建设,探索了一条集科技创新、生产示范、技术推广、科普教育、观光旅游、商业贸易"六位一体"的农业科研单位建设现代农业科技园区综合发展新模式,取得了多项农业科技成果,发挥了农业科技园区的科技引领作用,这种模式已推广到广东、四川、江苏、吉林、湖北、海南等地,促进了当地现代农业的发展。     

蜿蜒在海边的绿藤——珠海高新区绿道示范段设计浅析

绿道是供城乡居民休闲游憩的开敞空间,珠海高新区示绿道示范段（以下简称示范段）的设计独具特色,体现在将土地资源有限、可建设空间较少的问题转化为设计亮点,赋予恰当的主题,趋利避害,使绿道的价值空间发挥至最大。     

香蕉新品种——‘华农中把’的选育

‘华农中把’是以广东‘东莞中把’香蕉吸芽经60Coγ射线辐照后从诱变的植株中选育的新品种,经诱变和后续选育后稳定突变的性状为果实甜度增大。该品种主要综合性状如下:假茎高度210~265 cm,果穗近圆柱形,果穗质量21~25 kg。未熟果皮绿色,果实催熟后皮金黄色,果肉黄白色,味甜香,可溶性固形物为20.3%,可溶性糖18.1%,可滴定酸0.42%,品质优良。     

Protective effects of Shengfu injections on limbs in ischemia/reperfusion injury

AIM:To study the protective effects of Shengfu injections on the limbs in ischemia/reperfusion injury. METHODS:30 healthy rats at the same age were divided into 5 groups randomly. Group A was the simple reperfusion of ischemic limbs. Group B and C were injected with the Shengfu injections through femoral arteries at doses of 10 mL/kg and 20 mL/kg. Group D and E were injected with the Shengfu injections through femoral arteries at doses of 10 mL/kg and 20 mL/kg right after reperfusions. Blood samples were collected from femoral veins 1 h before femoral vessels were blocked, 1 h and 2 h after reperfusions in all animals. The concentrations of the CPK, GOT, SOD and MDA in the blood samples were determined. RESULTS:MDA increased, SOD, CPK, GOT decreased markedly in the therapeutic groups.CONCLUSION:The Shengfu injections surely protected the limbs from ischemia/reperfusion injury, the better effects was observed when the drug was administered before operation at the dose of 20 mL/kg.     

Variation of serum NSE and S-100 β in patients with acute cerebral infarction subtypes

AIM: To explore clinical significance of the serum changes of neuron-specific enolase (NSE)and S-100 β protein (S-100 β) during acute cerebral infarction. METHODS: 59 acute cerebral infarction patients were classified as total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), lacunar infarcts (LACI) and posterior circulation infarcts (POCI). Their serum NSE and S-100 β concentrations were determinated by enzyme linked immunosorbent assay (ELISA) during stroke onset 6 d, and compared with 32 controls. RESULTS: The every time point serum NSE concentration of TACI was higher than controls (P＜0.01), and its highest value occured at 3 d after the onset. The every time point concentration of PACI was also higher than controls (P＜0.05), its highest value occured at 1 d after the onset. The increment of serum S-100 β synchronized with serum NSE change in TACI. The S-100 β of PACI started to increase at 3 h after the onset, its highest value occured at 1 d after the onset, and concentration at 6 h, 1 d, 3 d and 6 d was markedly higher than controls (P＜0.05). However, the every time point NSE and S-100 β concentrations of LACI and POCI increased unmarkedly compared with control group. CONCLUSIONS: The serum NSE and S-100 β changes in acute period (contains acute early period) of cerebral infarction subtypes might be different. These results might help to treat acute cerebral infarction according to the classification.     

Inducible expression of enhanced green fluorescent protein by interleukin-1α, interleukin-1β and Toll-like receptor 2 promoters in goat mammary epithelial cells in response to bacterial challenges

The development of a bacteria-inducible expression system has several advantages compared with persistent expression of anti-bacterial proteins in milk to prevent and treat mastitis. The present study determined whether mastitis responsive promoters could regulate enhanced green fluorescent protein (EGFP) expression in goat mammary epithelial cells (GMECs) in response to challenges with Escherichia coli, Staphylococcus aureus or Streptococcus agalactiae. The level of expression of interleukin (IL)-1α was significantly increased in GMECs challenged with E. coli, S. aureus or S. agalactiae compared with untreated GMECs. IL-1β was induced by E. coli and S. aureus, while Toll-like receptor 2 (TLR2) was induced by E. coli only.GMECs were transfected with IL-1α, IL-1β and TLR2 promoter-EGFP reporter gene lentiviral expression vectors and the levels of expression of EGFP were measured by flow cytometry and Western blot analysis after bacterial challenge. EGFP expression driven by the IL-1α and IL-1β promoters was higher in GMECs challenged with E. coli, S. aureus or S. agalactiae than in untreated GMECs. There were no differences in EGFP expression driven by the TLR2 promoter between GMECs challenged with S. aureus or S. agalactiae and untreated GMECs, but EGFP expression was significantly increased in GMECs challenged with E. coli. Overall, these results indicate that the promoters of some bacteria-inducible genes can regulate EGFP expression in GMECs in response to bacterial challenges. This bacteria-inducible expression strategy could be used for production of mastitis resistant animals by regulating the expression of anti-bacterial proteins in the mammary gland.     

短截修剪程度对‘红灯’甜樱桃~(13)C和~(15)N分配利用的影响

以2年生‘红灯’(Prunus avium L.‘Hongdeng’)/东北山樱(Cerasus sachalinensis Kom.)为试材,研究了不同短截程度对13C和15N分配和利用的影响。结果表明,新梢生长期,短截处理修剪促进了碳水化合物向根系分配,极重度短截处理使叶片和新梢中13C分配率分别减少了29.15%和7.3%,粗根和细根中13C分配率增加了46.65%和48.43%。随着时间的推移,短截处理的叶片和新梢的13C分配率均显著高于对照,多年生枝干的13C分配率随短截程度的增加而减小,根系的13C分配率以中短截最低,极重度短截最高。各处理15N利用率从高到底依次为中度短截对照极重度短截,在新梢停长期差别最大,3个处理15N利用率分别为6.91%、5.54%和3.60%;多年生枝干15N分配率随短截程度的增加而减小,短截处理叶片和新梢的15N分配率随短截程度的增加而增加。     

Effect of glucocorticoid-treated dendritic cells on asthmatic Th2 response

AIM: To investigate the effect of dexamethasone-treated dendritic cells (DCs) on Th2 cytokine production from autologous T cells in asthmatic patients and explore the mechanisms by studying the effect of dexamethasone on differentiation, maturation and function of DCs from patients with asthma. METHODS: Human peripheral blood monocyte-derived DCs generated from asthmatic patients and healthy subjects were cultured in the absence or presence of dexamethasone. The phenotypic characterization of DCs was analyzed by flow cytometry. The mature DCs were harvested, washed, and then cocultured in vitro with autologous T cells purified by a nylon cotton column. The DC-T coculture supernatants were collected after 72 h incubation and analyzed for levels of IL-5 and IFN-γ by ELISA. RESULTS: The concentrations of IL-5 in the culture supernatants of DC-T coculture were significantly up-regulated in patients with asthma compared with that in healthy controls ［(145.13±89.76) ng/L vs (50.28±22.37) ng/L, P<0.01］. The level of IFN-γ in the DC-T coculture supernatants tended to be decreased in asthmatic patients than that in healthy controls, although this difference did not achieve statistical significance ［(197.58±76.32) ng/L vs (220.46±65.34) ng/L, P>0.05)］. There were significantly decreased levels of IL-5 by autologous T cells primed by dexamethasone-treated mature DCs from asthmatic patients ［(45.39±19.61) ng/L vs (145.13±89.76) ng/L, P<0.01］, alterations not observed from healthy controls (P>0.05). IFN-γ production was decreased by autologous T cells primed by dexamethasone-treated mature DCs from both asthmatic patients and healthy controls ［asthma group: (40.21±22.89) ng/L vs (197.58±76.32) ng/L, P<0.01; healthy controls: (56.78±20.37) ng/L vs (220.46±65.34) ng/L, P<0.01］. Dexamethasone-treated DCs exhibited decreased expression of CD83 (P<0.01) and increased expression of CD14 (P<0.01) in both asthmatic patients and healthy controls. CONCLUSION: DCs of asthmatic patients induce a Th2-skewed cytokine production from autologous T cells. Dexamethasone-treated DCs inhibit the Th2 reactions, and this effect is probably mediated through the pathway that dexamethasone inhibits DCs maturation and skews the macrophage/DC balance towards the macrophage side and thus directs the development more towards the macrophage lineage.     

华南地区优质高产水稻品种(组合)的适应性研究

【目的】筛选出适合于华南地区种植的水稻品种(组合)直接用于生产,或作为育种材料间接利用。【方法】采用完全随机试验设计,2019年早季在广东省珠海市对5个优质高产水稻品种(组合)‘华航48’、‘粳籼优0405’、‘粳籼优0505’、‘软华优1179’和‘软华优6100’进行了示范种植试验,考察了产量性状及其构成因素和外观品质性状,对照为优质稻‘美香占2号’。【结果】5个参试材料均属于大粒高产类型,单穴有效穗数均不到22,低于对照‘美香占2号’(24);单穗实粒数超过117粒、千粒质量大于20 g,均显著大于对照(对照分别为85.8粒和17.9 g);单穴粒质量大于47.3 g,比对照增产28%以上。5个参试材料外观品质性状均稍逊于对照,表现为粒长9.7 mm、粒宽2.5 mm、粒长/粒宽3.8、粒投影周长20.5 mm和粒投影面积16.8 mm2。相关分析结果表明,单穗实粒数、千粒质量、粒宽、粒投影面积与产量呈显著正相关;粒长、粒长/粒宽、粒投影周长与产量呈显著负相关,进一步证实了单穗实粒数与千粒质量的增产作用,也反映了外观品质与产量之间的矛盾。【结论】‘华航48’、‘软华优1179’和‘软华优6100’在华南地区早季表现优异,可直接推广应用;‘粳籼优0405’和‘粳籼优0505’适合于产量目标的生产,或作为高产优质育种的中间材料。     

miR-221 changes resistance of lung cancer cells to gefitinib by regulating PTEN

AIM: To explore the effect of microRNA-221 (miR-221) on resistance of lung cancer cells to gefitinib, and to investigate its related mechanism. METHODS: RT-qPCR was used to detect the levels of miR-221 expression between gefitinib-sensitive cell line PC9 and gefitinib-resistant cell line PC9/GR. The PC9/GR cells were transfected with miR-221 inhibitor by Lipofectamine 2000. The drug sensitivity of these cells to gefitinib was determined by CCK-8 assay. The protein expression level of phosphatase and tensin homologue deleted on chromosome ten (PTEN) was determined by Western blot. The 3'-UTR of PTEN was cloned into luciferase reporter vector and its luciferase activity was detected to verify whether miR-221 targets PTEN. RESULTS: The expression level of miR-221 in the PC9/GR cells was significantly higher than that in the PC9 cells (P<0.05). The protein expression level of PTEN in the PC9/GR cells was lower than that in the PC9 cells (P<0.05). The IC₅₀ of gefitinib was significantly reduced in the PC9/GR cells after transfection with miR-221 inhibitor (P<0.05). The protein expression level of PTEN in the cells transfected with miR-221 inhibitor was increased as compared with control group and blank group (P<0.05). Inhibition of miR-221 expression enhanced the enzymatic activity of luciferase reporter vector of PTEN. CONCLUSION: miR-221 enhances the resistance of lung cancer cells to gefitinib by down-regulating the protein expression of PTEN.