梨枣叶片和茎段再生体系的建立

用不同浓度配比的生长素和细胞分裂素诱导梨枣叶片和茎段愈伤组织的产生,并研究了不定芽诱导的最佳配方,建立了梨枣叶片和茎段的再生体系.结果表明,梨枣叶片愈伤组织诱导的最佳培养基为MS+2,4-D 1.5 mg·L-1+6-BA 0.5 mg·L-1;茎段为MS+2,4-D 1.0 mg·L-1+6-BA 0.5 mg·L-1.叶片不定芽诱导的最佳培养基为MS+IBA 0.1 mg·L-1+6-BA 1.5 mg·L-1. AgNO3能阻止叶片外植体褐化并有效地促进叶片愈伤组织分化.茎段能在同一培养基上产生愈伤组织并直接分化出不定芽.     

玉米芽尖培养中的高频率体细胞胚胎发生与植株再生(简报)

通过诱导玉米芽尖产生胚性愈伤组织,建立起高频率植株再生的玉米芽尖培养实验体系。在MS+1.0mg·L-16-BA+0.2mg·L-12,4-D+500mg·L-1CH的培养基上诱导愈伤组织并继代培养1次后,将愈伤组织转移到Ms+0.5mg·L-16-BA+0.4mg·L-1IBA+500mg·L-1CH的分化培养基上,可形成大量的体细胞胚胎。组织学观察表明,体细胞胚胎主要发生在胚性愈伤组织表面与表层下部。不同基因型的芽尖形成愈伤组织和再生植株的能力不同。     

大叶秦艽的组织培养与植株再生

以秦艽的叶和下胚轴为外植体,成功地诱导出愈伤组织和再生植株.诱导愈伤组织最合适的培养基为附加2 m g·L- 1 2 ,4 - D和0 .5 mg·L- 1 6 - BA的MS培养基,诱导率可达到10 0 % .愈伤组织转移到附加2 mg·L- 12 ,4 - D和0 .5 mg·L- 1 KT和5 0 0 m g·L- 1 L H的MS培养基上进行继代培养,增殖后的愈伤组织转移到附加0 .1mg·L- 1 2 ,4 - D和0 .5 m g·L- 1 6 - BA的MS分化培养基上进行分化,其分化率可达到86 .6 7% ,将分化出的芽转接到不加激素的MS上,结果可生长出大量的分化苗.     

对生玉米离体培养再生体系的建立

以对生玉米的雌、雄幼穗为外植体,研究了不同质量浓度激素及其组合对愈伤组织诱导、再分化苗和试管苗生根的影响,建立了对生玉米离体培养再生体系。结果表明：长度为15-17 mm的雌、雄幼穗能够诱导出质量较好的愈伤组织,但只有来自于雄幼穗的愈伤组织才能再生成苗。适合愈伤组织诱导的培养基为Ms+1．5-2．0 mg·L-12,4-D+0．5 mg·L-16-BA+0．5 mg·L-1 NAA+500 mg·L-1脯氨酸+1000 mg·L-1水解酪蛋白+30 g·L-1蔗糖;适合愈伤组织再分化培养基为MS+1．5-2．0 mg·L-1 6-BA+0．1 mg·L-1 NAA+500 mg·L-1水解酪蛋白+30 g·L-1 蔗糖;适合试管苗生根培养基为1／2 MS+0．25-0．5 mg·L-1 IBA+20 g·L-1蔗糖。     

利用丛生芽和愈伤组织微繁技术培养紫茎泽兰的研究

通过丛生芽直接增殖和愈伤组织再分化两条途径建立紫茎泽兰的无性系,可为进一步研究紫茎泽兰入侵的分子生态机制提供植物材料。结果表明:MS+BA2.0mg·L-1+NAA0.05mg·L-1为丛生芽增殖的最适培养基,MS+BA0.1mg·L-1+NAA0.1mg·L-1和MS+BA2.0mg·L-1+NAA0.2mg·L-1分别适于叶片愈伤组织的诱导和分化,而1/2MS+IAA0.1mg·L-1对生根最有利。     

蒙花忍冬的组织培养与快速繁殖研究

以金银花 蒙花 品系的茎段为外植体 ,于 MS和 B5附加不同激素配比的培养基上 ,探讨愈伤组织形成和丛生芽诱导及生根培养的条件 .诱导愈伤组织和丛生芽的培养基为 B5+BA2 .0 m g· L- 1 +KT0 .2～ 0 .5 mg· L- 1+IAA 0 .5～ 1 .0 mg· L- 1 +L H 1 0 0 0 m g· L- 1 ,继代增殖培养的培养基为 B5+BA 2 .0 m g· L- 1 +KT 0 .5 m g·L- 1 +IAA1 .0 m g· L- 1 +L H1 0 0 0 m g· L- 1和 B5+BA2 .0 mg· L- 1 +KT0 .36 m g· L- 1 +IAA1 .0 mg· L- 1+CH 1 0 0 0 m g· L- 1 +1 / 2 MS :大量元素 ,生根培养基为 1 / 2 MS +IBA 0 .2 mg· L- 1 +L H 1 0 0 0 mg·L- 1 .结果表明 L H和 CH在金银花愈伤组织和丛生芽诱导方面具明显的作用     

野葛叶片和茎段高频再生体系的建立

探讨几种因子对野葛叶片和茎段高频再生体系建立的影响。采用植物组织培养、正交实验和单因子实验的方法。野葛叶片和茎段的最佳消毒方式为70%酒精处理30 s后再用0.1%HgCl₂处理15 min;野葛叶片愈伤组织诱导的最佳培养基为MS+NAA 1.0 mg·L^-1+2,4-D 2 mg·L^-1,野葛茎段愈伤组织诱导的最佳培养基为MS+NAA 0.5 mg·L^-1+6-BA 1.0 mg·L^-1+2,4-D 2 mg·L^-1;暗培养更有利于野葛愈伤组织的诱导;野葛叶片和茎段愈伤组织诱导的最佳蔗糖浓度均为30 g·L^-1;野葛叶片愈伤组织的最佳出芽培养基为MS+NAA 1.0 mg·L^-1+6-BA 3.0 mg·L^-1,而野葛茎段愈伤组织的最佳出芽培养基为MS+ NAA 0.5 mg·L^-1+KT 2 mg·L^-1;光照培养更有利于野葛叶片和茎段愈伤组织芽的再分化;野葛叶片愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 0.5 mg·L^-1,而野葛茎段愈伤组织再生芽生根的最佳培养基为MS+NAA 0.5 mg·L^-1+PP₃₃₃ 3.0 mg·L^-1;野葛叶片和茎段愈伤组织再生芽生根的最佳蔗糖浓度均为30 g·L^-1;叶片再生苗移栽的最佳PP₃₃₃浓度为1.0 mg·L^-1,茎段再生苗移栽的最佳PP₃₃₃浓度为3.0 mg·L^-1;叶片和茎段再生苗的最佳移栽基质均为蛭石:珍珠岩（2:1）。     

海滨锦葵胚轴愈伤组织诱导及植株再生

以海滨锦葵(Kosteletzkya virginica)胚轴为外植体,在9种不同激素配比的培养基上进行愈伤组织诱导、继代培养、不定芽分化及生根培养,确定了植株再生的最适培养条件:(1)愈伤组织诱导最适培养基为MS+IAA 1．0 mg·L-1+KT 0.3 mg·L-1+sucrose 30 g·L-1+agar 8 g·L-1,愈伤组织诱导率为93．94％;(2)不定芽诱导最适培养基为MS+IAA 0．1 mg·L-1+ZT 0．5 mg·L-1+sucrose 30 g·L-1+agar 8 g·L-1,不定芽诱导率为65．83％;(3)生根最适培养基为MS+sucrose 30 g·L-1+ agar 8 g·L-1,生根率为96．67％。炼苗移栽后,成活率可达85％。     

马铃薯叶片高效再生体系的建立

以4个马铃薯栽培品种为试材,进行了叶片离体再生研究,结果表明:东农303、鄂1号叶片愈伤组织诱导的最佳培养基为MS+6-BA2.5mg·L-1+NAA0.2mg·L-1;费乌瑞它为MS+6-BA2.0mg·L-1+NAA0.1mg·L-1;夏波帝为MS+6-BA2.0mg·L-1+NAA0.2mg·L-1,愈伤组织的诱导率均可达100%.诱导不定芽分化的最佳培养基分别是:费乌瑞它、鄂1号为MS+6-BA2.5mg·L-1+GA35.0mg·L-1;东农303为MS+6-BA1.0mg·L-1+IAA0.1mg·L-1+GA32.5mg·L-1;夏波帝为MS+6-BA2.5mg·L-1+IAA0.5mg·L-1+GA32.5mg·L-1,其不定芽分化率分别达94.3%、100%、100%和90%.     

虎杖的组织培养与快速繁殖

以虎杖茎段、叶柄、叶片为外植体探讨了愈伤组织诱导、分化和植株再生的条件,筛选出茎段生长培养基为1/2MS+BA1.0mg·L-1+KT0.5mg·L-1+NAA0.2mg·L-1,茎段、叶柄和叶片外植体愈伤组织诱导培养基为MS+BA1.0～2.0mg·L-1+KT0.2～0.5mg·L-1+NAA0.2～0.5mg·L-1或MS+BA2.0～3.0mg·L-1+KT0.2～0.5mg·L-1+2,4-D0.5mg·L-1;丛生芽诱导培养基为MS+BA2.0mg·L-1+KT0.5mg·L-1+IBA0.2mg·L-1+LH1000;不定根及根状茎诱导培养基为1/2MS+IBA0.2mg·L-1.     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Production of arsine and methylarsines in soil and in culture

Arsenate, arsenite, monomethylarsonate, and dimethylarsinate were added to different soils, and evolution of gaseous arsenical products was determined over 3 weeks. Arsine was produced in all three soils from all substrates, whereas methylarsine and dimethylarsine were produced only from methylarsonate and dimethylarsinate, respectively. At least three times more arsine than dimethylarsine was produced in soil incubated with dimethylarsinate. Resting cell suspensions of Pseudomonas and Alcaligenes produced arsine as the sole product when incubated anaerobically in the presence of arsenate or arsenite. In all instances, no trimethylarsine was observed, nor could any evidence be shown for the methylation of any arsenical substrate in soil or in culture. It was concluded that reduction to arsine, not methylation to trimethylarsine, was the primary mechanism for gaseous loss of arsenicals from soil.     

Growth and mitogenic effects of arylphorin in vivo and in vitro

In insects, developmental responses are organ- and tissue-specific. In previous studies of insect midgut cells in primary tissue cultures, growth-promoting and differentiation factors were identified from the growth media, hemolymph, and fat body. Recently, it was determined that the mitogenic effect of a Manduca sexta fat body extract on midgut stem cells of Heliothis virescens was due to the presence of monomeric alpha-arylphorin. Here we report that in primary midgut cell cultures, this same arylphorin stimulates stem cell proliferation in the lepidopterans M. sexta and Spodoptera littoralis, and in the beetle Leptinotarsa decemlineata. Studies using S. littoralis cells confirm that the mitogenic effect is due to free alpha-arylphorin subunits. In addition, feeding artificial diets containing arylphorin increased the growth rates of several insect species. When tested against continuous cell lines, including some with midgut and fat body origins, arylphorin had no effect; however, a cell line derived from Lymantria dispar fat body grew more rapidly in medium containing a chymotryptic digest of arylphorin.     

Antiplatelet and antithrombotic activities of purpurogallin in vitro and in vivo

Enzymatic oxidation of pyrogallol was efficiently transformed to an oxidative product, purpurogallin (PPG). Here, the anticoagulant activities of PPG were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of thrombin and activated factor X (FXa). And, the effects of PPG on expression of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated in tumor necrosis factor (TNF)-α activated human umbilical vein endothelial cells (HUVECs). Treatment with PPG resulted in prolonged aPTT and PT and inhibition of the activities of thrombin and FXa, as well as inhibited production of thrombin and FXa in HUVECs. In addition, PPG inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. PPG also elicited anticoagulant effects in mice. In addition, treatment with PPG resulted in significant reduction of the PAI-1 to t-PA ratio. Collectively, PPG possesses antithrombotic activities and offers a basis for development of a novel anticoagulant. [BMB Reports 2014; 47(7): 376-381]     

Growth and reproduction of Arabidopsis thaliana in relation to storage of starch and nitrate in the wild-type and in starch-deficient and nitrate-uptake-deficient mutants

We have investigated the interactions between resource assimilation and storage in rosette leaves, and their impact on the growth and reproduction of the annual species Arabidopsis thaliana. The resource balance was experimentally perturbed by changing (i) the external nutrition, by varying the nitrogen supply; (ii) the assimilation and reallocation of resources from rosette leaves to reproductive organs, by cutting or covering rosette leaves at the time of early flower bud formation, and (iii) the internal carbon and nitrogen balance of the plants, by using isogenic mutants either lacking starch formation (PGM mutant) or with reduced nitrate uptake (NU mutant). When plants were grown on high nitrogen, they had higher concentrations of carbohydrates and nitrate in their leaves during the rosette phase than during flowering. However, these storage pools did not significantly contribute to the bulk flow of resources to seeds. The pool size of stored resources in rosette leaves at the onset of seed filling was very low compared to the total amount of carbon and nitrogen needed for seed formation. Instead, the rosette leaves had an important function in the continued assimilation of resources during seed ripening, as shown by the low seed yield of plants whose leaves were covered or cut off. When a key resource became limiting, such as nitrogen in the NU mutants and in plants grown on a low nitrogen supply, stored resources in the rosette leaves (e.g. nitrogen) were remobilized, and made a larger contribution to seed biomass. A change in nutrition resulted in a complete reversal of the plant response: plants shifted from high to low nutrition exhibited a seed yield similar to that of plants grown continuously on a low nitrogen supply, and vice versa. This demonstrates that resource assimilation during the reproductive phase determines seed production. The PGM mutant had a reduced growth rate and a smaller biomass during the rosette phase as a result of changes in respiration caused by a high turnover of soluble sugars ( Caspar et al. 1986 ; W. Schulze et al. 1991 ). During flowering, however, the vegetative growth rate in the PGM mutant increased, and exceeded that of the wild-type. By the end of the flowering stage, the biomass of the PGM mutant did not differ from that of the wild-type. However, in contrast to the wild-type, the PGM mutant maintained a high vegetative growth rate during seed formation, but had a low rate of seed production. These differences in allocation in the PGM mutant result in a significantly lower seed yield in the starchless mutants. This indicates that starch formation is not only an important factor during growth in the rosette phase, but is also important for whole plant allocation during seed formation. The NU mutant resembled the wild-type grown on a low nitrogen supply, except that it unexpectedly showed symptoms of carbohydrate shortage as well as nitrogen deficiency. In all genotypes and treatments, there was a striking correlation between the concentrations of nitrate and organic nitrogen and shoot growth on the one hand, and sucrose concentration and root growth on the other. In addition, nitrate reductase activity (NRA) was correlated with the total carbohydrate concentration: low carbohydrate levels in starchless mutants led to low NRA even at high nitrate supply. Thus the concentrations of stored carbohydrates and nitrate are directly or indirectly involved in regulating allocation.     

Importance of guanine nitration and hydroxylation in DNA in vitro and in vivo

Guanine (Gua) modification by nitrating and hydroxylating systems was investigated in DNA. In isolated calf thymus DNA, 8-NO(2)-Gua and 8-oxo-Gua were dose-dependently formed with peroxynitrite, and 8-NO(2)-Gua was released in substantial amounts. Myeloperoxidase (MPO) with H(2)O(2) and NO(2)(-) reacted with calf thymus DNA to form 8-NO(2)-Gua dose dependently without release of 8-NO(2)-Gua. The frequency of strand breaks was higher than the sum of 8-NO(2)-Gua and 8-oxo-Gua, particularly in the MPO-treated DNA, indicating the importance of other types of damage. The activation of human neutrophils and lymphocytes with phorbol ester did not induce 8-NO(2)-Gua and 8-oxo-Gua in their nuclear DNA. However, 8-NO(2)-Gua was found in calf thymus DNA co-incubated with activated neutrophils in the presence of NO(2)(-). No significant formation of 8-NO(2)-Gua was found in liver DNA from mice treated with Escherichia coli lipopolysaccharide. The incubation of peroxynitrite or MPO-H(2)O(2)-NO(2)(-)-treated DNA with formamidopyrimidine glycosylase (Fpg) released 8-oxo-Gua, but not 8-NO(2)-Gua, indicating that 8-NO(2)-Gua is not a substrate for Fpg. Although 8-NO(2)-Gua was generated in isolated DNA by different nitrating systems, other types of damage were formed in abundance, and the lesion could not be found reliably in nuclear DNA, suggesting that the biological importance is limited.