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131.
The influence of two enzyme solutions, differing only in the presence or absence of Macerozyme, on protoplast yield, colony formation and transient GUS (-glucuronidase) activity was studied. For all parameters tested the presence of Macerozyme during protoplast isolation had a negative influence. Using an enzyme solution without Macerozyme suspension aggregates gave up to 4.4 times higher protoplast yield and plating efficiencies were increased up to 10-fold. Further, protoplasts isolated without macerozyme showed a 5.2-fold higher GUS activity in transient gene expression. Apart from the presence of Macerozyme, longer incubation (3 compared with 1.5 h) of cell aggregates in the enzyme solution also had a negative effect on transient transformation efficiency. These data demonstrate that protoplast isolation conditions have a profound effect on transient gene expression and it is proposed that these factors will also influence stable transformation efficiency.Abbreviations CP
cellulase pectolyase
- CPM
cellulase pectolyase Macerozyme
- 2,4-d
2,4-dichlorophenoxyacetic acid 相似文献
132.
White grubs (larval scarabaeids) are now recognized as being important pests of groundnut (peanut) in many parts of the world
because of their ability to damage roots. A method of simulating white grub damage to groundnut plants was developed to obtain
an indication of how the feeding activity of these insects influences plant growth. The effect of root cutting and drought
stress on water uptake and biomass production was evaluated, with roots being cut at three depths in the late vegetative and
early podfilling stages. As groundnut plants are often grown under conditions of drought stress, the effects of which would
be accentuated by root damage, this factor was introduced into the experiment. Plant water-use measurements indicated that
the root systems of plants cut 30 days after emergence (DAE) and watered twice a week became fully functional again after
40 days. Pod and total biomass production were however significantly less than those of the uncut control plants, with drought
stress reducing yields below the well-watered controls, particularly when cut at 10 cm below the soil surface. The root systems
of plants cut 51 DAE did not regrow to any appreciable extent, and rates of plant water-use remained less than half of the
uncut control plants. Over all treatments, there was a strong positive correlation between total (and pod) biomass and plant
water-use. It was concluded that the phenological stage of the plant at which root damage occurred had a profound influence
on the subsequent recovery in root growth and function, and ultimately on pod yield. 相似文献
133.
Eczema of the nipple is an important symptom presenting to the general surgeon in the out-patient department. the diagnosis of Paget's disease of the nipple has traditionally been made by incision biopsy necessitating at least a local anaesthetic. We present 14 patients with nipple skin change, in whom the technique of scrape cytology was used to identify patients with Paget's disease. In our series eight cases of Paget's disease were successfully identified by scrape cytology with no false negatives or positives. We suggest that this is a quick, easy, non-invasive method of screening eczema of the nipple in the out-patient clinic. 相似文献
134.
人参寡糖素对三七悬浮培养细胞生长的效应 总被引:4,自引:0,他引:4
从人参培养细胞的细胞壁中分离纯化到不同分子量的单体人参寡糖素。试验结果表明命名为人参寡糖素Ⅶ和人参寡糖素Ⅷ的两种寡糖素对三七悬浮培养细胞的生长具有明显的促进作用,其增长率分别为19.34%和10.58%,人参寡糖素Ⅶ的适宜浓度为5—10mg/l。在高浓度下(大于25mg/l)稍抑制培养细胞生长。在细胞培养22天(指数生长期)后.加入10mg/l的人参寡糖素Ⅶ.然后再培养2天。其生长速率即提高,加入人参寡糖素Ⅷ后.缩短了三七细胞悬浮培养生长的延缓期.提前进入对数生长期和指数生长期,并在对数生长期和指数生长期作用最明显,因而最终收获时培养细胞的产率增加。 相似文献
135.
小麦叶蜂危害的产量损失与防治指标研究 总被引:2,自引:1,他引:1
当小麦叶蜂幼虫数量相等时,在较干旱的年份(1988)危害较重;而在气候较湿润的年份(1989)危害较轻。虫量与产量损失成正相关(r=0.9821**),其中以25头/m2幼虫危害的产量损失突增,达显著水平,可以认定为防治指标。 相似文献
136.
Yoshihito Shirai Masaaki Yamaguchi Atsuko Kobayashi Akihiro Nishi Hisao Nakamura Hiroki Murakami 《Cytotechnology》1994,14(2):129-146
The growth yields for glucose and glutamine of murine hybridoma cells entrapped in collagen gel particles were examined during the growth phase. The immobilized hybridoma cells were cultivated in a fluidized bed fermenter where the medium was circulating to supply oxygen separately. Procedures to supply an alkaline solution for adjusting the pH level strongly affected the growth yields. A direct supply of the alkaline solution to the cultivation system reduced both the growth yields for glucose and glutamine, probably due to a local increase in pH level. On the other hand, when fresh medium in which the pH was adjusted to around 8.5 was added to the cultivation system, the growth yields were unchanged even at the same pH level as when direct alkaline supply was used. These results suggest that an indirect alkaline supply could be recommended to ajust the pH level when using medium-circulating-fermenters. 相似文献
137.
Vascular smooth muscle cell membranes from prehypertensive rats of the Milan hypertensive strain (MHS) were used to examine adenylyl cyclase activity and its regulation by guanine nucleotide regulatory proteins (G-proteins). Basal adenylyl cyclase activity was similar in MHS and Milan normontensive strain (MNS) membranes. Forsokolin (10?4 M) produced a significantly greater stimulatory response in MHS membranes, but this was not observed with NaF (10?2 M). Isoporterenol (10?4 M) caused a significantly decreased stimulation of adenylyl cyclase activity in MHS membranes, while prostaglandin E1 (10?5 M) produced similar responses in the two strains. Gi function and GTP responses, as observed by biphasic effects of GTP on isoproterenol-stimulated membranes, were similar in both strains. The levels of Gi2α and Gqα/G11α were similar in the two strains, while the levels of Gsα (44 and 42 kDa forms) and the β-subunit were significantly reduced by ~20% in MHS membranes. The α-subunit of Gi3 was dramatically reduced by ~80% in MHS membranes. The affinities of β-adrenergic receptors for the antagonist, cyanophindolol, were similar in the two strains; however, the number of β-adrenoceptors was substantially reduced in MHS membranes. These findings may be of relevance to altered vascular reactivity and transmembrane ion distribution observed in the MHS. 相似文献
138.
139.
In vivo photosynthetic electron transport does not limit photosynthetic capacity in phosphate-deficient sunflower and maize leaves 总被引:8,自引:0,他引:8
The effects of extreme phosphate (Pi) deficiency during growth on the contents of adenylates and pyridine nucleotides and the in vivo photochemical activity of photosystem II (PSII) were determined in leaves of Helianthus annuus and Zea mays grown under controlled environmental conditions. Phosphate deficiency decreased the amounts of ATP and ADP per unit leaf area and the adenylate energy charge of leaves. The amounts of oxidized pyridine nucleotides per unit leaf area decreased with Pi deficiency, but not those of reduced pyridine nucleotides. This resulted in an increase in the ratio of reduced to oxidized pyridine nucleotides in Pi-deficient leaves. Analysis of chlorophyll a fluorescence at room temperature showed that Pi deficiency decreased the efficiency of excitation capture by open PSII reaction centres (φe), the in vivo quantum yield of PSII photochemistry (φPSII) and the photochemical quenching co-efficient (qP), and increased the non-photochemical quenching co-efficient (qN) indicating possible photoinhibitory damage to PSII. Supplying Pi to Pi-deficient sunflower leaves reversed the long-term effects of Pi-deficiency on PSII photochemistry. Feeding Pi-sufficient sunflower leaves with mannose or FCCP rapidly produced effects on chlorophyll a fluorescence similar to long-term Pi-deficiency. Our results suggest a direct role of Pi and photophosphorylation on PSII photochemistry in both long-and short-term responses of photosynthetic machinery to Pi deficiency. The relationship between φPSII and the apparent quantum yield of CO2 assimilation determined at varying light intensity and 21 kPa O2 and 35 Pa CO2 partial pressures in the ambient air was linear in Pi-sufficient and Pi-deficient leaves of sunflower and maize. Calculations show that there was relatively more PSII activity per mole of CO2 assimilated by the Pi-deficient leaves. This indicates that in these leaves a greater proportion of photosynthetic electrons transported across PSII was used for processes other than CO2 reduction. Therefore, we conclude that in vivo photosynthetic electron transport through PSII did not limit photosynthesis in Pi-deficient leaves of sunflower and maize and that the decreased CO2 assimilation was a consequence of a smaller ATP content and lower energy charge which restricted production of ribulose, 1-5, bisphosphate, the acceptor for CO2. 相似文献
140.
The interactions of VO2+ with phytate to form both soluble and insoluble complexes, have been studied by electronic absorption spectroscopy. A soluble
1∶1 VO2+: phytate complex is formed at pH <1. At higher pH-values insoluble complexes are produced. Two different solid complexes,
obtained respectively at pH=2 and 4, were isolated and characterized. The maximal bonding ratio of VO2+: phytate was found to be 4, on the basis of a pH binding profile. 相似文献