高温胁迫下葡萄叶片蛋白激酶的诱导形成与活性变化

以"京秀"葡萄(Vitis vinifera L.cv.Jingxiu)幼苗为试材,研究了高温胁迫激活的蛋白激酶的类型和活性.结果表明,高温胁迫10～60min明显地激活了一个分子量约为52 kD的蛋白激酶,该蛋白激酶能将凝胶中所嵌入的髓鞘碱性蛋白(MBP)磷酸化,在放射自显影中表现出很高的放射活性,而对凝胶中的组蛋白-Ⅲ(histone-Ⅲ)则没有这样的作用.在溶液反应体系中该蛋白激酶对MBP也表现出很高的磷酸化活性,而对histone-Ⅲ却无作用.Ca2 对其活性变化无显著影响.酪氨酸特异性蛋白磷酸酶(YOP)对该激酶的活性有显著的钝化作用.结果表明该52 kD蛋白激酶是MAPK家族中的一种.     

An enclosed-chamber labeling system for the safe <Superscript>14</Superscript>C-enrichment of phytochemicals in plant cell suspension cultures

Summary Various plant secondary products have been implicated in the promotion of good health or the prevention of disease in humans, but little is known about the way they are absorbed in the gut, or in which tissues they are deposited throughout the body. While these issues could be studied if the phytochemicals were isotopically labeled, generating labeled molecules often is problematic because many compounds of interest can be synthesized only in planta at present. In order to generale ¹⁴C-labeled phytochemicals of high radioactive enrichment, we developed an enclosed-chamber labeling system in which cell suspension cultures can be safely and efficiently grown when supplied with ¹⁴C-enriched precursors. The system is designed to hold culture flasks within a clear, polyacrylic compartment that is affixed to the top of a rotary shaker. The flow-through gas exchange nature of the system allows for O₂ replenishment and complete capture of respired ¹⁴CO₂ throughout the entire period of cell culture. Air is circulated internally with the aid of a small fan, and chamber air temperature is monitored continuously with an internal temperature probe and data logger. Production runs of 12–14 d with Vaccinium pahalae (ohelo berry) and Vitis vinifera (grape) suspension cultures, using [¹⁴C]sucrose as the carbon source, demonstrated a 20–23% efficiency of ¹⁴C incorporation into the flavonoid-rich fractions. Further studies with ohelo cell cultures showed that flavonoids were produced with either sucrose or glucose as the carbohydrate source, although flavonoid productivity (measured as anthocyanins) was higher with sucrose. This comprehensive chamber system should have broad applicability with numerous cell types and can be used to generate a wide array of labeled phytochemicals.     

An in vivo experimental system to study sugar phloem unloading in ripening grape berries during water deficiency stress

An in vivo experimental system-called the 'berry-cup' technique-was developed to study sugar phloem unloading and the accumulation of sugar in ripening grape berries. The berry-cup system consists of a single peeled grape berry immersed in a buffer solution in a cup prepared from a polypropylene syringe. A small cross-incision (2 mm in length) is made on the stylar remnant of a berry during its ripening phase, the skin of the berry then being easily peeled off, exposing the dorsal vascular bundles without damaging either these or the pulp tissue of the berry. The sites of sugar phloem unloading are thus made directly accessible and may be regulated by the buffer solution. In addition, the unloaded photoassimilates are easily transported into the buffer solution in the berry-cup. With the berry-cup technique, it takes 60 min to purge the sugar already present in the apoplast, after which the amount of sugar in the buffer solution is a direct measure of the sugar unloading from the grape berry phloem. The optimum times for sampling were 20 or 30 min, depending on the type of experiment. Sugar phloem unloading was significantly inhibited by the inclusion of either 7.5 mm NaF or 2.5 mm PCMB in the buffer solution. This study indicates that sugar phloem unloading in ripening grape berries is via the apoplastic network and that the process requires the input of energy. The system was shown to be an appropriate experimental system with which to study sugar phloem unloading in ripening grape berries, and was applied successfully to the study of berry sugar unloaded from grapevines subjected to water stress. The results showed that water deficiency inhibits sugar unloading in grape berries.     

Role of the egg parasitoid Trichogramma minutum in biological control of the grape berry moth, Endopiza viteana

During a survey for natural enemies of thegrape berry moth (GBM) Endopiza viteana(Clemens) in northwestern Pennsylvania, wefound that Trichogramma minutum Riley isthe only native egg parasitoid with thepotential to limit berry damage by preventingegg hatch. Natural parasitism, however, wasfound to be unreliable for providing economicpest suppression. Early season populations ofthe parasitoid are extremely low and may be theresult of inadequate alternative host eggs foroverwintering. Also, wild grapes and theirwooded habitats were found to be favored byT. minutum. Parasitism was low incultivated grapes and in wild grapes growingclose to commercial vineyards (possibly due tothe deterrent effect of insecticides) andhighest in sites 1.5 km from commercialvineyards. Adult T. minutum emergingfrom GBM eggs were exceptionally small andshowed little vigor. Parasitized eggs oftenfailed to produce adult parasitoids. Pre-adults in such eggs had poorly formed mouth-parts or lacked them altogether. Inundativereleases of laboratory-reared T. minutumin border rows of vineyards are suggested as apossible alternative to the current practice ofapplying carbamate and organophosphateinsecticides, which are inimical to beneficialarthropods.     

<Emphasis Type="SmallCaps">l</Emphasis>-Homoarginine suppresses exocrine pancreas in rats

Summary.  Previously, we found that guanidinated casein, a l-homoarginine-containing protein, was a more potent stimulator of pancreatic enzyme secretion than intact casein in rats. In this study, we examined secretory response and adaptation of the exocrine pancreas to the administration of free l-homoarginine in normal and bile-pancreatic juice (BPJ)-diverted rats. An intraperitoneal injection of l-homoarginine (10 mg/rats) produced immediate and transient reduction in pancreatic secretion in BPJ-diverted rats, but not in normal rats. The BPJ-diverted rats were fed with either a 25% casein, 45% casein, or 45% casein diet supplemented with l-homoarginine (19 g/kg diet) for 4 days. Feeding of a diet containing l-homoarginine inhibited the pancreatic adaptation induced by the high-protein diet. These results indicate that l-homoarginine has an inhibitory effect on the secretion and production of exocrine pancreatic enzyme in BPJ-diverted rats, and l-homoarginine may have an antagonistic effect on CCK receptors. Received July 1, 2002 Accepted August 28, 2002 Published online December 20, 2002 Authors' address: Dr. Hiroshi Hara, Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-9, Nishi-9, Kita-ku, Sapporo 060-8589, Japan E-mail: hara@chem.agr.hokudai.ac.jp     

Involvement of polyamines in gibberellin-induced development of seedless grape berries

The roles of polyamines (PAs) in the development of seedless grape berries induced by gibberellin (GA₃) was investigated. The development of seedless grape berries was stimulated by the application of putrescine (Put), but not by that of spermidine (Spd) and spermine (Spm), regardless of the presence of GA₃. At harvest, the fresh weight of seedless grape berries treated with 500 ppm Put + 25 ppm GA₃ and 500 ppm Put increased to 111 and 112%, respectively, of the control. Treatment with methylglyoxal-bis (guanyl hydrazone), a potent inhibitor of S-adenosylmethionine decarboxylase that plays a role in Spd and Spm synthesis, did not affect the development of seedless grape berries induced by 100 ppm GA₃. The application of 100 ppm GA₃ significantly increased endogenous free Put levels. Levels of free Spd and Spm were not affected by GA₃. Although the levels of endogenous perchloric acid insoluble bound PAs were higher than those of free PAs, obvious changes in the levels of bound PAs were not observed. These results indicate that free Put is implicated in the development of seedless grape berries induced by GA₃.     

Proteomic analysis of human gastric juice: a shotgun approach

Gastric juice is the most proximal fluid surrounding the stomach tissue. The analysis of gastric juice protein contents will thus be able to accurately reflect the pathophysiology of the stomach. This biological fluid is also a potential reservoir of secreted biomarkers in higher concentration as compared to the serum. Unlike the rest of the gastrointestinal fluids, there were very few studies reported on gastric juice proteome. To date, the proteins that routinely populate this biofluid are largely unknown. This is partly due to the technical difficulties in processing a sample that contains a collection of other gastrointestinal fluids, especially saliva. In this study, we attempt to profile the protein components of the gastric fluids from chronic gastritis patients using a direct shotgun proteomics approach. These data represent the first report of the proteome of human gastric juice with gastritis background.     

Production of <Emphasis Type="SmallCaps">d</Emphasis>-lactic acid from sugarcane molasses,sugarcane juice and sugar beet juice by <Emphasis Type="Italic">Lactobacillus delbrueckii</Emphasis>

Lactobacillus delbrueckii was grown on sugarcane molasses, sugarcane juice and sugar beet juice in batch fermentation at pH 6 and at 40°C. After 72 h, the lactic acid from 13% (w/v) sugarcane molasses (119 g total sugar l⁻¹) and sugarcane juice (133 g total sugar l⁻¹) was 107 g l⁻¹ and 120 g l⁻¹, respectively. With 10% (w/v) sugar beet juice (105 g total sugar l⁻¹), 84 g lactic acid l⁻¹ was produced. The optical purities of d-lactic acid from the feedstocks ranged from 97.2 to 98.3%.     

葡萄叶中总黄酮的提取工艺研究

目的：从葡萄叶中提取总黄酮。方法：采用正交试验法研究葡萄叶总黄酮的最佳提取工艺条件,考察了乙醇浓度、回流温度、回流时间及料液比四因素对葡萄叶总黄酮提取率的影响。结果：确立了葡萄叶总黄酮最佳提取条件为：45％的乙醇为溶剂、液料比为1：40、提取温度为60％、提取时间2h,在最佳工艺条件下葡萄叶总黄酮含量为5．329mg／g。     

Fermentation of cashew apple juice to produce high added value products

The use of agriculture substrates in industrial biotechnological processes has been increasing because of its low cost. Cashew apples are considered an agriculture low cost product in the Brazilian Northeast because the cashew cultivation is done mainly to produce cashew nuts. About 90% of the cashew apples production is lost in the field after removing the nut. In this work, the use of clarified cashew apple juice as substrate for microbial cultivation was investigated. The results showed that cashew apple juice is a good source of reducing sugars and can be used to grow Leuconostoc mesenteroides to produce high added value products such as dextran, lactic acid, mannitol and oligosaccharides.