患红体病凡纳滨对虾肝胰腺NAGase基本性质的改变研究

[目的]为虾养殖过程中红体病的诊断和控制提供重要的理论依据。[方法]分别测定健康和患红体病的凡纳滨对虾（Litopenaeus vanname）的肝胰腺N-乙酰-β-D-氨基葡萄糖苷酶（EC3.2.1.52,NAGase）的比活力及其性质差异。[结果]2种来源NAGase的比活力、基本酶学性质等均存在差异。对虾患红体病后,肝胰腺NAGase的比活力和最适温度下降,但催化反应动力学常数Km、Vm值和活化能上升。[结论]该研究表明NAGase与对虾患病可能存在着密切关系。     

铺地竹叶片对结球生菜种子发芽及幼苗生长的影响

采用基质盆栽试验,研究了铺地竹(Sasa argenteastriatus E.G.Camus)叶片对结球生菜(Lactucasativa L.var.capitata L.)种子萌发和幼苗生长的影响,结果表明,铺地竹叶片粉末对结球生菜种子的萌发和幼根生长具有一定的抑制作用,随着浓度的增加抑制作用增强,在50～200 g/m2的范围内,幼根抑制率为12.15%～28.91%。在50～100 g/m2的用量下,铺地竹叶片对结球生菜苗长表现为促进生长作用,而在200 g/m2时,则表现为抑制生长作用。施用铺地竹叶片后3 d、6 d、9 d和12 d,结球生菜幼苗的叶绿素含量特别是叶绿素a的含量显著减少,随着基质中叶片粉末浓度的增加,结球生菜叶绿素含量降低,叶绿素a含量高低依次为对照、低浓度处理、中浓度处理、高浓度处理。随着处理后时间的延长,竹叶对结球生菜叶片叶绿素a含量的影响减弱。这个结果进一步验证了自然条件下铺地竹叶片对植物生长的化感效应,说明其具有开发植物源除草剂的潜力,为研究铺地竹叶片中的化感物质提供了佐证。     

Abscisic Acid May Alter the Salicylic Acid‐Related Abiotic Stress Response in Maize

The effect of 0, 0.05 or 0.1 mm abscisic acid treatment on chilling tolerance and salicylic acid‐related responses was investigated in young maize seedlings (Zea mays L., hybrid Norma). Although the pre‐treatment of maize seedlings with abscisic acid slightly decreased the chlorophyll content, it also reduced the level of chilling injury caused by 6 days of cold treatment at 5 °C. Under normal growth conditions, increased levels of bound salicylic acid and of bound ortho‐hydroxycinnamic acid were observed in the leaves during abscisic acid treatment. In the roots, abscisic acid did not affect the free and bound salicylic acid levels, but increased the amount of free and bound ortho‐hydroxycinnamic acid. The activity of glutathione‐S‐transferase increased on the 3rd day of abscisic acid treatment, whereas it did not change when followed by cold stress, compared with the control leaves. In the roots, the activities of glutathione reductase, glutathione‐S‐transferase and ascorbate peroxidase increased during the abscisic acid treatment, and those of glutathione‐S‐transferase and ascorbate peroxidase were also stimulated when abscisic acid pre‐treatment was followed by cold stress, compared with the control roots. Our results suggest that an overlap may exist between the abscisic acid‐induced cold acclimation and the salicylic acid‐related stress response.     

低温与氮耦合对水稻内源激素含量的影响

【目的】探究不同耐冷氮高效水稻材料内源激素代谢特点,以阐明氮营养对提高水稻耐冷性的调节机理。【方法】以水稻近等基因系耐冷氮高效I16和冷敏氮低效I67为材料,采用水培试验,研究人工气候室模拟低温胁迫与4个氮肥水平(10,20,40和60 mg/L)耦合对水稻根、叶中内源激素吲哚乙酸(IAA)、细胞分裂素(CTK)、赤霉素(GA)、脱落酸(ABA)含量的影响及其互作效应。【结果】随水稻生育进程,根和叶中IAA、CTK、GA含量呈先升高后降低的趋势,在开花期达到峰值,ABA含量在成熟期达峰值。水稻根和叶中IAA、CTK、GA含量随施氮水平增加而升高,ABA则相反;在相同施氮水平下,低温抑制IAA、CTK、GA合成,促进ABA升高,4种激素含量呈现I16高于I67,叶高于根。低温与中氮耦合对水稻根和叶中IAA、CTK、GA的调控为正效应,低温与高氮耦合调控ABA为负效应,中氮可使水稻维持较高内源激素含量,这是增强水稻耐冷性的内在机理之一。【结论】在低温和氮肥耦合下,维持根叶中较高的IAA、CTK、GA、ABA含量,以及施氮对根、叶激素耦合效应的差异,是引起水稻耐冷性和氮素利用效率差异的重要生理调节因素。     

Ethyl acetate fraction of flavonoids from Polygonum hydropiper L. modulates pseudorabies virus-induced inflammation in RAW264.7 cells via the nuclear factor-kappa B and mitogen-activated protein kinase pathways

Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses.     

水稻根系育种研究进展

水稻（Oryza sativa L.）根系对水稻的生长发育及产量形成具有至关重要的作用。根据目前水稻根系育种的研究现状，分析了水稻根系育种对提高产量、改变形态特征和生理特性的重要性，并对其研究前景进行了分析和展望。     

黑龙江西部低山丘陵区应用保水剂造林适宜施用量试验研究

保水剂不同施用量的盆栽梯度试验与不同拌种比例的直播造林试验的结果表明：随着保水剂施用量的增加，植苗造林维持苗木成活生长时间逐渐延长，其中维持新植苗木持续成活生长15天左右的施用量分别为：小黑杨（2根1干）10～12 g，丁香（2年实生苗）8～10 g，樟子松（2年实生苗）6～8 g；直播拌种造林则随着加拌保水剂比例增大，胡枝子出苗量逐渐提高，1∶10、1∶15及1∶20比例与对照差异显著，当年苗高同时逐渐提高，1∶10比例与对照差异显著。通过与人工浇水比较，在保证造林成活率的前提下，植苗造林施用保水剂可分别节约造林抚育成本：小黑杨1142．5元／hm2、丁香1110元／hm2、樟子松1353．34元／hm2。     

5‐Aminolevulinic Acid Activates Antioxidative Defence System and Seedling Growth in Brassica napus L. under Water‐Deficit Stress

The present study assesses the effects of 5‐aminolevulinic acid (ALA, 0, 0.1, 1 and 10 mg l^?1) on the growth of oilseed rape (Brassica napus L. cv. ZS758) seedlings under water‐deficit stress induced by polyethylene glycol (PEG 6000, 0 and ?0.3 MPa). Water‐deficit stress imposed negative effects on seedling growth by reducing shoot biomass, cotyledon water potential, chlorophyll content and non‐enzymatic antioxidants (glutathione and ascorbic acid) levels. On the other hand, water‐deficit stress enhanced the malondialdehyde (MDA) content, reactive oxygen species (ROS) production, enzymatic antioxidants activities, reduced/oxidized glutathione ratio (GSH/GSSG) and reduced/oxidized ascorbic acid (ASA/DHA) ratio in seedlings. Application of ALA at lower dosages (0.1 and 1 mg l^?1) improved shoot weight and chlorophyll contents, and decreased MDA in rape seedlings, whereas moderately higher dosage of ALA (10 mg l^?1) hampered the growth. The study also indicated that 1 mg l^?1 ALA improved chlorophyll content, but reduced MDA content and ROS production significantly under water‐deficit stress. Lower dosages of ALA (0.1 and 1 mg l^?1) also enhanced GSH/GSSG and ASA/DHA as compared to the seedlings under water‐deficit stress. The antioxidant enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase and superoxide dismutase) enhanced their activities remarkably with 1 mg l^?1 ALA treatment under water‐deficit stress. It was also revealed that 1 mg l^?1 ALA treatment alone induced the expression of APX, CAT and GR substantially and under water‐deficit stress conditions ALA treatment could induce the expression of POD, CAT and GR to a certain degree. These results indicated that 0.1–1 mg l^?1 ALA could enhance the water‐deficit stress tolerance of oilseed seedlings through improving the biomass accumulation, maintaining a relative high ratio of GSH/GSSG and ASA/DHA, enhancing the activities of the specific antioxidant enzymes and inducing the expression of the specific antioxidant enzyme genes.     

水稻半外卷叶突变体sol1的表型分析与基因定位

适度卷曲有利于提高水稻叶片的光合效率,增加植株光合产物的有效积累量。我们利用甲基磺酸乙酯(EMS)处理籼型水稻保持系西农1B,获得一个稳定遗传的水稻半外卷叶突变体。该突变体从十叶期开始各叶片逐渐向外卷曲直至半卷状,并伴随茎秆半矮化和叶片披垂,暂被命名为semi-outcurved leaf 1(sol1)。与野生型(WT)相比,sol1的叶片卷曲指数均达到30%以上(P<0.01);倒一、倒二、倒三、倒四节节间长度和穗长极显著缩短,倒一、倒二、倒三叶的叶夹角显著或极显著增加;有效穗数、千粒重、每穗实粒数、结实率显著或极显著下降,一次枝梗数则增加11.3%(P<0.05)。sol1的蒸腾速率、胞间CO2浓度、气孔导度显著高于野生型。石蜡切片显示,sol1倒一叶的泡状细胞体积变小,数量显著增多,表皮细胞体积略微增大。遗传分析表明,sol1的半外卷叶性状受1对隐性核基因调控,定位于6号染色体标记JY6-3和JY6-10之间165 kb的物理范围内,共含15个注释基因。qRT-PCR结果表明,与泡状细胞相关的内卷基因和外卷叶基因RL14、Roc5、REL1在突变体sol1中呈不同程度的上调,NRL、BRD1、OsHox32、ADL1、LC2则呈不同程度的下调。研究结果为SOL1基因的克隆和功能研究奠定了基础。