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71.
采用组织培养及显微观察技术,以金花茶植株茎段、叶片、花药及离体培养的金花茶体细胞胚为试验材料,对松散型愈伤组织的获得及悬浮细胞系的建立进行了研究。结果表明:在黑暗条件下,以金花茶体细胞胚切块为外植体,在MS+KT 0.5 mg/L+NAA 8.0 mg/L+硝酸银5mg/L+蔗糖30 g/L培养基上诱导出愈伤组织后,将其转接到该诱导培养基上连续培养3个月,最后从培养物中挑选状态良好的松散型愈伤组织在分别含有肌醇与硝酸银的2种培养基上交替培养,可以获得金花茶松散型愈伤组织;方差分析表明:蔗糖添加量、肌醇添加量及硝酸银添加量均对金花茶悬浮培养液细胞密度有显著影响且后两者分别与光照条件存在相互作用;将松散型愈伤组织在分别添加100 mg/L肌醇与2.5 mg/L硝酸银的液体增殖培养基上交替培养,可以建立并保持金花茶悬浮细胞系。该研究结果可为金花茶大规模细胞培养提供科学依据。  相似文献   
72.
刘丽杰  苍晶  王军虹  于晶 《麦类作物学报》2015,35(10):1333-1340
为了探讨外源ABA对苗期低温下冬小麦植株蔗糖代谢的调节作用,以抗寒性强的品种东农冬麦1号和抗寒性弱的品种济麦22为试验材料,在三叶期分别于不同温度下经ABA处理48 h后取叶片和地下茎,研究外源ABA对苗期低温下冬小麦的蔗糖含量及蔗糖代谢相关酶基因表达的影响。结果表明,外源ABA处理使低温下抗寒性强的东农冬麦1号中积累了更多的蔗糖,尤其是叶片,而在济麦22中则抑制了蔗糖的积累。4℃以上温度时,外源ABA促进了东农冬麦1号叶片和地下茎中UGP在蔗糖合成中的作用;在4℃以下低温时,外源ABA则促进了UGP在蔗糖分解中的作用。4℃以上温度时,外源ABA提高了东农冬麦1号叶片中Ta SPS基因和地下茎中Ta SAInv基因的表达,而抑制了济麦22各器官中Ta SPS基因和Ta SAInv基因的表达。此外,4℃以上温度时,外源ABA抑制了两个小麦品种各器官中Ta SS基因的表达。表明抗寒性强的东农冬麦1号对外源ABA可能更加敏感,其蔗糖合成能力的提高将有利于冬小麦植株抵御低温,进而维持植株的存活。  相似文献   
73.
从药用植物巴戟天根部组织中克隆了3个1-脱氧-D-木酮糖5-磷酸合成酶基因MoDXS1、MoDXS2-1和MoDXS2-2,其全长cDNA分别为2 676、2 667和2 610 bp,编码区序列长度为2 154、2 121和2 190 bp,编码717、706和729个氨基酸.BlastP序列比对分析表明MoDXS蛋...  相似文献   
74.
Nitric oxide synthase (NOS) is an enzyme that catalyzes the formation of nitric oxide (NO), an important biological messenger from L-arginine. There are considerable evidence showing the expression of NOS in mammalian tissues. Information on distribution of NOS activities in various organs and tissues of fish is rare. Non-functional NOS activities were documented in fish semi-quantitatively either by an indirect nicotine-adenine-dinucleotide-phosphate diaphorase (NADPH-d) activity histochemical staining method or by an immunohistochemical method using a cross-reacting antibody to brain NOS. Report on the functional levels of NOS activities in fish is lacking. This report represent the first attempt to document the functional NOS levels in various fish organs and tissues. Constitutive NOS (cNOS) activities in various organs of big-head carp (Aristichthys nobilis) was measured by a chemiluminescence method with a detection limit as low as 10 mol of NO produced. It was found that constitutive NOS activity was highest in the brain, followed by the intestine, stomach, retina, olfactory lobe, swim bladder, skeletal muscle, heart, kidney, ovary and liver. NOS activity could not be detected in the gill filaments. Omission of NADPH in the reaction mixture caused a 57–100% decrease in cNOS activities. However, omission of arginine in the mixture only caused a 56–87% drop in cNOS activities. When compared with cNOS activities documented from other species, a similar pattern of cNOS activities in the various organs and tissues of big-head carp could be seen.  相似文献   
75.
回顾了近十五年来国内外对各科植物查尔酮合酶基因CHS分子进化的研究成果,并结合作者近年来对兰科植物CHS基因分子进化的研究结果,对兰科植物CHS基因分子进化和功能趋异的机制展开综述,揭示了植物中普遍存在的CHS基因分子进化以及伴随的功能趋异的现象和机制,初步探讨了CHS基因分子进化与生物进化和自然选择的关系。  相似文献   
76.
77.
Annual ryegrass (Lolium rigidum) is the only weed species to have evolved resistance to the broad‐spectrum herbicide glyphosate in Australia. A population that had failed to be controlled by glyphosate was collected from a vineyard in the Adelaide Hills region of South Australia. Dose–response experiments on this population (SLR 77) showed that it was glyphosate resistant, with an LD50 that was 1.9–3.4 times higher than that of a susceptible population (VLR 1). The movement of radiolabelled glyphosate within SLR 77 plants showed that this population did not have the differential glyphosate translocation mechanism of resistance common to several other Australian glyphosate‐resistant populations. Subsequent analysis of shikimic acid accumulation within the plant after glyphosate treatment showed that this population accumulated significantly less shikimic acid than a susceptible population, but more than a glyphosate‐resistant population with the translocation mechanism, indicating the possible involvement of another mechanism of resistance. Sequencing of a portion of the SLR 77 5‐enolpyruvylshikimate‐3‐phosphate synthase gene was carried out and a mutation causing an amino acid change at position 106 from proline to threonine was identified. This mutation is likely to be responsible for glyphosate resistance in this population, as mutations in this position have been found to be responsible for glyphosate resistance in goosegrass (Eleusine indica) from Malaysia. This paper represents the first report of target‐site glyphosate resistance in L. rigidum and provides evidence that this species has at least two mechanisms of glyphosate resistance present in Australia.  相似文献   
78.
Intact spinach chloroplasts were used to determine if clomazone, 5-OH clomazone, and/or 5-keto clomazone inhibited the chloroplastic isoprenoid pathway. When isopentenyl pyrophosphate was used as a precursor, neither clomazone nor the clomazone metabolites (5-OH clomazone and 5-keto clomazone) inhibited the formation of products separated by HPLC in the organic phase. However, when pyruvate, a substrate for the first committed step of the pathway, was used as a precursor, both 5-keto clomazone and fosmidomycin reduced the formation of a non-polar product and increased the formation of a polar product in the organic phase. Only 5-keto clomazone, not 5-OH clomazone or clomazone, inhibited the formation of an additional product other than fosmidomycin in the aqueous phase from pyruvate incorporation. In an in vitro assay, 5-keto clomazone inhibited DXP synthase, the enzyme catalyzing the first committed step of the chloroplastic isoprenoid pathway. Therefore, our studies show that neither clomazone nor 5-OH clomazone inhibits the chloroplastic isoprenoid pathway, only 5-keto clomazone does.  相似文献   
79.
The rhizogenesis of GF677, Early Crest, May Crest and Arm King stem cuttings during the year was investigated. The results showed significant differences in the rooting percentage between different dates of cutting collection and also between the four cultivars. Among these, GF677 generally had the highest rooting percentage. Rooting of cuttings was high in October, November and February and relatively low in the periods March–September and December–January. Interactions among cultivars were also found.  相似文献   
80.
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