Results with leaf discs showed that the effects of SNP on φPSⅡ could be prevented by bovine hemoglobin (a powerful NO scavenger), while a mixture of NO2- and NO3- (the decomposition product of NO or its donor SNP) had much less influence on φPSⅡ than SNP, indicating that effects of exogenous SNP on PS Ⅱ photochemical activity was mainly due to NO generation.
Experiments with isolated rose leaf discs cultured in Se solution in dark for 4 d showed that Se decreased MDA content and POD activity, and inhibited the decrease of reducing sugar and chlorophyll. 0.1～0.5 mg/L Se increased soluble protein content and CAT activity, 0.1～0.2 mg/L Se promoted SOD activity and retarded the increase of plasmalemma permeability.
The infectivity of Tobacco mosaic virus(TMV) in Nicotiana glutinosa was strongly inhibited(more than 80%) by 0.6 mg·mL~(-1) paeonol that was extracted from Paeonia suffruticoss after mixing paeonol with TMV for 10 min; the paeonol had inhibiting effect on the replication of TMV in infected leaf discs;
从牡丹皮中提纯的丹皮酚结晶(0.6 mg.mL-1)与烟草花叶病毒(Tobacco m osaic virus,TMV)混合10 m in后对TMV枯斑抑制率达80%以上,说明丹皮酚对叶圆片中的病毒复制具有抑制作用;
1. Photosynthesis、photoinhibition and its protective mechanism of cucumber leavesduring chilling stress in the low lightPhotosynthetic rate decreased in cucumber leaf discs during chilling stress and decrease innet photosynthetic rate (Pn) and stomatal conductance (Gs) were accompanied by increase inintercellular CO2 concentration (Ci) and decrease in the carboxylation efficency (CE).
2. In the leaf disk experiment, after 10~(-5)mol/L of Put treatment, endogenous Put content in the Red Fuji apple achieved the peak in 2 hours, endogenous Spd content achieved the peak in 6 hours, endogenous Spm content achieved the peak in 24 hours.
The inheritance of resistance to Plasmopara viticola was studied with 1018 F1 hybrids crossed between 11 clones of 5 wild species native to China and Vins vinlfera cultivars by natural infection in vineyard and leaf disc inoculation in vitro.
Evaluation of resistance to kanamycin of leaf disc from Kan-resistant plantlets indicated that the transformation efficiency of Jincheng orange (Citrus sinensis Osb). Xinhui orange (C. sinensis Osb) and Shatian pummelo (C. grandis) was up to 46.3%, 39.5% and 43.7% respectively.
By the leaf disc meathods a number of CMVCP transgene-tobacco-plants areobtained. The resuIts of DNA, RNA point hebridization and DNA southern blot with theradioactive CMVcp probe indicated that the CMVCP genes are cooperated into andexpressed in tobacco genome. After leaf infection with virus, the transgeneplants showedhigher resistance to CMV virus.
When disks incubated for 3 days are provided with ~(14)C-proline, the radioactivity incorporated into disks and proteins is lower in the culture with MS basal medium or with MS basal medium containing 2 ppm 6 BA and 0.3 mM hydroxyproline, in both of which the disks grow slowly, than in the culture with MS basal medium containing only 2 ppm 6 BA, in which the disks grow rapidly.
But the WCLA didn't inhibit infectivity of TMV when TMV incubated with WCLA. The inhibiting rate of garlic naphtha and WCLA on multiplication of TMV were 82.6% and 69.1% when the infected leaves by TMV were dipped in solution of 400 μg/mL garlic naphtha or WCLA;
The direction of transient expression of GUS and GFP in Agrobacterium mediated 3-4 days transformed leaf discs of Populus tomentosa, indicating that the promoter did have bidirectional transcriptional activities simultaneously in cells and tissues.
We studied the changes in lectin activity in tobacco leaf discs and potato tubers treated with polysaccharides (chitosan, glucomannan, and dextran sulfate), enzymes (cellulase and pectinase), or monosaccharides (glucose and glucosamine).
The content of membrane lectins in the chloroplasts (tobacco leaf discs) usually decreased considerably immediately after the treatment (1-2 days) but increased later (2-4 days).
Tobacco leaf discs were genetically transformed with anAgrobacterium tumefaclens strain harbouring pBIC-3SNP1.
Effects of osmotic stress on antioxidant enzymes activities in leaf discs of PSAG12-IPT modified gerbera
The data obtained suggested the existence of two metastable states of a transgene in the leaf disk somatic cells (active and silenced), which could be associated with DNA modification, i.e., methylation of cytosine within the nptII gene sequence.
Plutella xylostella pupae were not affected by the nematodes, although mortality in leaf disk bioassays after application of nematodes in water seldom surpassed 50%.
In leaf disk feeding tests, the fungicide thiram (tetramethylthiuram disulfide), as technical material or formulated as thiram 50% or 75% (AI) was also an effective feeding deterrent.
In a leaf disk assay, mortality of late stage DBM larvae ranged from >amp;lt;7% caused bySteinernema kushidai Mamiya to >amp;gt;95% caused byS.
Neem oil deterred feeding by pear sawfly, Caliroa cerasi L., larvae (Hymenoptera: Tenthredinidae), both in choice and in no-choice cherry leaf disk bioassays.
Jute (Corchorus capsularis L.) plants were grown in sandculture with Hoagland's nutrient solution containing five levels (1/4 N, 1/2 N, 1 N, 2 N, 4 N) of ammonium nitrogen or nitrate nitrogen. An investigation was made on the effects of various nitrogen levels and forms on photosynthesis, photorespiration and nitrate reduction in jute plants. The results as the following:
The differences in susceptibility to Plasmopara viticola among 140 cultivars of vitis vinifera were studied by inoculation on leaf discs in laboratory and on plants in greenhouse by sporocyst suspension of known concentration. A significant variation in the susceptibility to downy mildew was found among the studied cultivars, categorized into 3 conventional classes: very susceptible, susceptible and slightly susceptible.