Branched-chain constituents of Brussels sprout wax

The presence of a substantial proportion of branched, in addition to normal compounds, was confirmed in the alkyl ester and primary alcohol components     

半夏倒苗前后的细胞组织结构

探讨高温胁迫下半夏倒苗前后的组织学结构的变化,为揭示半夏倒苗的生物学机理提供参考依据。在半夏植株高15cm左右时,给予(32±1)℃的高温胁迫,于不同胁迫天数取半夏叶柄,经爱氏苏木精染液染色,用石蜡切片法制片,在显微镜下观察并照相。结果表明,随着高温胁迫时间的延长,半夏叶柄的维管组织结构被破坏越来越严重,细胞壁、细胞膜破裂,原生质外渗,核膜破裂,核仁溢出,有的细胞内核仁消失。     

Wheat sprout extract-induced apoptosis in human cancer cells by proteasomes modulation

Natural occurring modulators of proteasome functionality are extensively investigated for their implication in cancer therapy. On the basis of our previous evidences both on proteasomal inhibition by monomeric polyphenols, and on the characterization of wheat sprout hydroalcoholic extract, herein we thoroughly report on a comparative study of the effect of wheat sprout extract on both normal and tumour cells. Treatment of isolated 20S proteasomes with wheat sprout extracts induced a gradual inhibition of all proteasome activities. Next, two wheat sprout extract components were separated: a polyphenol and a protein fraction. Both components exerted an in vitro inhibitory effect on proteasome activity. HeLa tumour cells and FHs 74 Int normal cells were exposed to both fractions, resulting in different rates of proteasome inhibition, with tumour cells showing a significantly higher degree of proteasome impairment and apoptosis induction. Furthermore, a decrease in proteasome activities and in cell survival of the human plasmacytoma RPMI 8226 cell line, upon the same treatments, was observed. Collectively, our results provide additional evidences supporting the possible use of natural extracts as coadjuvants in cancer treatments.     

黄土高原马栏林区辽东栎更新特性研究

研究了黄土高原马栏林区主要植被类型中的辽东栎幼苗的数量特征,更新层幼苗、幼树的实生和萌生特性及其辽东栎在垂直结构上的数量分布。结果表明:(1)辽东栎幼苗在黄土高原马栏林区分布广泛且数量充足。不同的植被类型中辽东栎种群表现出不同的大小级结构,在油松—辽东栎混交林、油松林和辽东栎林中辽东栎种群的幼苗、幼树和成树均占一定的比例,而在油松—白桦混交林、白桦林、山杨林和山杨—白桦混交林中辽东栎种群则以幼苗和幼树为主。表明辽东栎种群在该地区植被的发展过程中将产生重要的作用。(2)辽东栎在这一地区是由实生和萌生的个体混合组成的。在各种植被类型中实生植株的密度都高于萌生植株,辽东栎种群的更新在该地区可能主要是通过实生植株来完成的,即辽东栎实生植株在更新过程中起重要的作用。但萌生植株作为辽东栎顺利通过瓶颈的一种手段,作为辽东栎种群繁衍和稳定的一种途径,在辽东栎种群的更新中也起着一定的作用。     

The effect of Brevicoryne brassicae on leaf area, dry matter distribution and amino acids of the Brussels sprout plant

Twenty-six direct or derived criteria were assessed, eight wk after infestation, of the effect of an initial inoculum of 0, 5, 25 or 50 Brevicoryne brassicae on the growth and dry matter distribution of Brussels sprout plants. Twenty-four of these criteria showed significant (P > 0.05) effects of aphid infestation, though increasing aphid infestation above 5/plant had little further effect. Total fresh and dry weight (as well as of the components — leaves, stems and roots) was reduced by 25–730 with infestation, particularly so the root. The number of leaves as well as individual leaf area was reduced, and leaves on infested plants were less efficient assimilators. This could be explained by the drain on assimilates caused by the aphids, the leaf curling and the reduced density of stomata. The latter was also considered to account partly for the increased moisture content of infested plants. There was a general reduction in the concentration of leaf amino acids.     

Growth of Salmonella on sprouting alfalfa seeds as affected by the inoculum size, native microbial load and Pseudomonas fluorescens 2-79

Aims: To investigate the growth of salmonellae on sprouting alfalfa seeds as affected by the inoculum size, microbial load and Pseudomonas fluorescens 2–79. Methods and Results: Alfalfa seeds pre‐inoculated with ≤10¹–10³ CFU g^?1 of salmonellae and with or without Ps. fluorescens 2–79 were sprouted in glass jars and the population of salmonellae were determined daily for up to 6 days. The population of salmonellae on germinating seeds reached the maximum 2–3 days after sprouting when total bacterial count reached the maximum (10⁹ CFU g^?1). The population of salmonellae on sprouting seeds not treated with Ps. fluorescens 2–79 showed a net increase of 3–4 log units. However, the population of salmonellae on alfalfa seeds treated with Ps. fluorescens 2–79 showed a net increase of only 1–2 log units. Disinfection of seeds with calcium hypochlorite enhanced the growth of salmonellae. Conclusions: Treatment of seeds with Ps. fluorescens 2–79 reduced the growth of salmonellae by 2–3 log units. Significance and Impact of the Study: The potential of Ps. fluorescens 2–79 as a biological agent for use in control of salmonellae on sprouting seeds was demonstrated and warrants further investigation.     

Shoot growth and tree architecture of saplings of the major canopy dominants in a warm-temperate rainforest

Sapling density, shoot growth, and sapling architecture were studied in five major canopy dominants both under closed canopy and gaps in a warm-temperate rainforest. The five species showed wide variations in distribution, shoot growth, and sapling architecture. Distylium racemosum and Quercus acuta had significantly higher sapling densities under closed canopy than in gaps. Castanopsis sieboldii and Machilus thunbergii had significantly higher sapling densities in gaps than under closed canopy. Quercus salicina showed no significant difference in sapling density between the two habitats. Under closed canopy, C. sieboldii and M. thunbergii had wider crowns than the other species. Distylium racemosum had the greatest number of terminal shoots among the species. Quercus acuta had a branchless small crown. Quercus salicina showed intermediate values in crown width, depth and the number of terminal shoots among the species. Distylium racemosum showed the greatest height-growth rate among the species under the closed canopy, but was the slowest in gaps. Castanopsis sieboldii and M. thunbergii showed the greatest height-growth rates among the species in gaps. Quercus salicina showed the slowest height-growth rates both under closed canopy and gaps. All of the five species showed low mortality under closed canopy. For the major canopy dominants: (i) sapling architecture may not be an important factor in determining mortality but it may be important for height-growth rate; and (ii) sprouting helps saplings to survive until gap formation and facilitates rapid growth in the gaps.     

Tree regeneration and future dynamics of the laurel forest on Tenerife,Canary Islands

Abstract. We studied two sites in the laurel forest of Tenerife to predict future changes in canopy composition. We used two projection methods: Horn's ‘Markovian Projection’, which utilizes information on juveniles in the vicinity of canopy trees, and a 'Stand Projection’, which ignores such information. We performed these projections both including and excluding a-sexual regeneration. Although all of our projections predict a change in species composition, inclusion of a-sexual reproduction decreased the magnitude of successional change. The persistence of Prunus lusitanica and Ilex canariensis appears to be highly dependent on a-sexual regeneration. Both the Markov- and stand projections predict a slight convergence in species composition between the two sites when only sexual regeneration is considered, and also a higher dominance of the shade-tolerant species Laurus azorica. When a-sexual regeneration is also considered, some divergence is shown, with less projected change in the stand projection than in the Markov projection. In spite of some differences between the models, general patterns such as an increase of shade-tolerant species (Laurus azorica and Prunus lusitanica) and a decrease of shade-intolerant species (Erica arborea, Erica scoparia and Myrica faya) are consistent.