Development of the infection strategy of the hemibiotrophic plant pathogen,Colletotrichum orbiculare,and plant immunity

The hemibiotrophic fungus Colletotrichum orbiculare forms appressoria as infection structures and primarily establishes biotrophic infection in cucumber epidermal cells. Subsequently, it develops necrotrophic infection. In the pre-invasion stage, morphogenesis of appressoria of C. orbiculare is triggered by signals from the plant surface. We found that C. orbiculare PAG1 (Perish-in-the-Absence-of-GYP1), a component of MOR [morphogenesis-related NDR (nuclear Dbf2-related) kinase network] plays an essential role as a key component of the plant-specific signaling pathway and that hydrolysis of cutin by a spore surface esterase creates a cutin monomer that constitutes a key plant-derived signal. Development of the infection structure of C. orbiculare is strictly regulated by the cell cycle and we found that proper regulation of G1/S progression via two-component GAP genes, consisting of BUB2 (Budding-Uninhibited-by-Benomyl-2) and BFA1 (Byr-Four-Alike-1) is essential for the establishment of successful infection. In the post-invasion stage, the establishment of the biotrophic phase of hemibiotrophic fungi is crucial for successful infection. We found that C. orbiculare WHI2 (WHIsky-2), an Saccharomyces cerevisiae stress regulator homolog, is involved in the phase transition from biotrophy to necrotrophy through TOR (Target of Rapamycin) signaling, and is thus essential for full pathogenesis.     

超声强化法提取蓝莓多糖的工艺研究

以蓝莓为材料,利用超声强化法提取蓝莓多糖。在单因素试验基础上,利用响应面法考察超声功率、提取时间、液固比对蓝莓多糖提取率的影响。得到最优提取工艺条件为: 超声功率600 W,超声时间 87 min,液固比49 mg/g,在此条件下,蓝莓多糖提取率理论值为4.93％,验证实测值为4.91％,与预测值接近,说明该试验方案可行。     

一个水稻卷叶基因rl(t)的精细定位

 叶片适度卷曲是水稻理想株型塑造的重要组成部分。卷叶基因rl(t)在杂合状态下可使叶片适度卷曲,增加水稻产量,具有较高的育种利用价值。以卷叶珍汕97B\[携带rl(t)基因\]与平展叶品种奇妙香（轮回亲本）杂交并回交的BC5F3和BC5F4为定位群体,在前人关于rl(t)的定位区间内设计了15对多态性分子标记,将rl(t)精细定位于第2染色体上分子标记P95053和P113.6之间的11 kb范围内,遗传间距约0.04 cM。区间内只包含1个释义基因,预测编码GL2类同源异型结构域,属于同源异型盒家族中的HD GL2类（也称为HD ZIP Ⅳ）转录因子。卷叶基因rl(t)的精细定位为克隆目标基因和研究其调控机理奠定了基础。     

抗淀粉样蛋白寡聚体单链抗体融合蛋白在真核细胞中表达的初步研究

阿尔茨海默病(Alzheimer’s disease,AD)是一种由脑内淀粉样蛋白(A)聚集引起的,以老年人记忆和认知功能丧失为临床表征的神经退行性疾病。研究表明,A寡聚体是AD发生发展的主要因素。应用自行筛选出的能够特异识别淀粉样蛋白寡聚体的单链抗体W20基因,构建了以绿色荧光蛋白为报告基因的真核表达载体pSNAV2.0-W20-EGFP,并应用流式细胞分选、蛋白免疫印迹以及荧光显微镜等技术对该单链抗体融合蛋白在真核细胞中的表达进行了初步研究,为针对AD的抗体基因治疗奠定了基础。     

Potato (Solanum spp.) in the hot tropics. VI. Plant population effects on soil temperature,plant development and tuber yield

Nine experiments were run at three hot tropical sites (5–12°S, 180–800 m) within Peru to quantify the influence of plant population on soil temperature and growth and yield of the potato.Radiation interception was greatest at the highest plant populations and soil cooling was directly proportional to the amount of crop cover over the soil, but no appreciable effect on the timing of tuber initiation was apparent. More stems per unit land area leading to a higher leaf area index (lai) were primarily responsible for greater interception of radiation at the higher plant populations, although some compensation in stem number per unit land area and in lai at lower populations was evident later in the season.In general, tuber yield increased linearly with increases in planted population over the range studied (2.7–12.5 plants m⁻², and in one experiment to 31.7 plants m⁻²), and was proportional to increases in the amount of intercepted radiation. Tuber yields ranged from 8 to 60 t ha⁻¹ over sites and populations. Vigorous clones with Solanum tuberosum spp. andigena in their genetic background constituted the exceptions to this linear trend, and for these clones yields declined at the highest populations, particularly when the rectangularity of planting vastly deviated from square patterns. Tuber yield of Solanum tuberosum spp. tuberosum and Neotuberosum (S. tuberosum spp. andigena selected for tuberization under long-day conditions) clones did not respond to variations in rectangularity of planting and, probably due to their small stature and early maturity, did not demonstrate signs of intense between-plant competition for tuber yield as measured with the Kira competition density index. In contrast, for clones with Solanum tuberosum ssp. andigena in their genetic background, maximum tuber yield at populations greater than 5.5 plants m⁻² was dependent on the rectangularity of planting, and declined as the latter deviated from squareness.Since the proportion of marketable tubers was scarcely affected by the planting densities, plant population of S. tuberosum ssp. tuberosum clones planted in hot climates should be as close as possible without limiting the amount of soil available for hilling-up.     

β-Glucan successfully stimulated the immune system in different jawed vertebrate species

Several reports have shown the positive effects of β-glucans on the immune. Howeverthese studies have a broad experimental design including β-glucans compounds. Consequently, a study using the same β-glucan molecule, administration route and experimental design is needed to compare the effects of β-glucan across vertebrate species. For this end, during 28 days we fed four different vertebrate species: mice, dogs, piglets and chicks, with two β-glucan molecules (BG01 and BG02). We measured the serum interleukin 2 as an indicator of innate immune response, the neutrophils and monocytes phagocytosis index as a cellular response and antibody formation as an adaptive response. The results clearly showed that the different β-glucan molecules exhibited biologically differently behaviors, but both molecules stimulate the immune system in a similar pattern in these four species. This finding suggests that vertebrates shared similar mechanisms/patterns in recognizing the β-glucans and confirms the benefits of β-glucans across different vertebrate species.     

黑液腐植酸肥料对棉花生长及土壤肥力的影响

通过在北疆布设的3种肥料(腐植酸液体肥料HALF-A、HALF-B、HALF-C)5个施肥水平的田间试验,研究了黑液腐植酸肥料对棉花生长及土壤肥力的影响。结果表明:(1)与常规肥料比,应用不同黑液腐植酸液体肥料,增产幅度达到8.54%~10.80%,提高单铃重0.2~0.3 g,对衣分和单株有效成铃数影响不大;(2)施用腐植酸液体肥料能够推迟棉花成熟2~4 d;(3)腐植酸液体肥料施用量2250kg/hm2以上时显著促进了棉花花后干物质的累积;(4)三种腐植酸液体肥料施用量3 000 kg/hm2时对棉花氮素养分的吸收促进作用最大,HALF-B在施用量2250 kg/hm2,HALF-C在3 000 kg/hm2时促进了棉花磷素养分的吸收,腐植酸液体肥料施用量3 750 kg/hm2以上时显著促进了棉花钾素养分的吸收;(5)施用腐植酸液体肥料对当年收获后土壤肥力影响不大。     

Quantification and comparison of wheat yield variation across space and time

Research about spatio-temporal variation of crop yield does not abound. From a precision agriculture (PA) perspective and particularly considering site-specific crop management (SSCM), this is an aberration. There is a serious need to further question how temporal variation of crop yield impacts ones ability to manage spatial variation. The aim of this study is to consider and develop new and existing approaches to this question. Spatio-temporal analysis was undertaken for two wheat fields in South Australia with 3 and 4 years of wheat yield data. Temporal analysis included the calculation of semi-variance across each field between pairs of years for the creation of maps and the calculation of rank correlations between pairs of years. These analyses supported previous notions that the magnitude of temporal variation is large compared with spatial variation. However, some consistence of spatial patterns between years was also observed for each of the fields indicating that considering magnitudes of variation alone is not an exhaustive analysis. A long-term (100 years) temporal analysis using variograms was undertaken for a single point simulated using the Agricultural Production Simulator Model (APSIM). The long-term analysis overcame the fact that 3 or 4 years of yield data are an extremely small sample size for the time dimension. This analysis provided some useful insight into temporal variation such as a large nugget variance accounting for 75% of the temporal variation and the cyclical nature of temporal yield variation. A novel use of pseudo cross semi-variograms was applied to a spatio-temporal analysis of yield variation for the two fields. This analysis provides a preliminary insight into identifying space–time variance equivalents. With greater depth of temporal crop yield data this is a promising perspective from which to identify optimal spatial management strategies.