Marine yeasts and bacteria as biological control agents against anthracnose on mango

The potential of four yeasts (Debaryomyces hansenii, Rhodotorula minuta, Cryptococcus laurentii and Cryptococcus diffluens) and three bacteria (Bacillus amyloliquefaciens, Bacillus subtilis and Stenotrophomonas rhizophila) with antagonistic capacity against anthracnose caused by Colletotrichum gloeosporioides in mango cv. Ataulfo fruit was investigated. Germination of C. gloeosporioides spores was significantly inhibited by all marine yeasts and bacteria strains of an in vitro test. When yeasts and bacteria were tested on mango fruit, the marine yeast D. hansenii 1R11CB strain and marine bacteria S. rhizophilaKM02 strain were the best antagonists to anthracnose (C. gloeosporioides), which significantly decreased disease incidence by 56% and 89%, respectively, and reduced lesion diameter by 91% and 92%, respectively. All the isolated strains of the phytopathogen, yeasts and bacteria were molecularly identified. Our results from in vitro and in vivo experiments suggest that marine yeasts and bacteria strains can be used as some effective biological control agents for anthracnose in mango.     

First Report of Botrytis cinerea Pers. on Salicornia bigelovii Torr. in North‐West México

Grey mould has been detected on Salicornia bigelovii Torr plants in nursery and in the wild in north‐west Mexico. Sampling of the grey mould was performed in the state of Sonora, Mexico, of wild as well as cultivated S. bigelovii plants. The samples were isolated, and based on morphology, the species was identified as Botrytis cinerea Pers. Koch's postulates were fulfilled by pathogenicity tests carried out in plated petri dishes on branches from the 3‐month‐old potted S. bigelovii plants. To our knowledge, this is the first report of the isolation and identification of the fungal pathogen B. cinerea from S. bigelovii in the north‐west Mexico.     

Phosphorylation of chicken growth hormone

The possibility that chicken growth hormone (cGH) can be phosphorylated has been examined. Both native and biosynthetic cGH were phosphorylated by cAMP-dependent protein kinase (and gamma -32P-ATP). The extent of phosphorylation was however less than that observed with ovine prolactin. Under the conditions employed, glycosylated cGH was not phosphorylated. Chicken anterior pituitary cells in primary culture were incubated in the presence of 32P-phosphate. Radioactive phosphate was incorporated in vitro into the fraction immunoprecipitable with antisera against cGH. Incorporation was increased with cell number and time of incubation. The presence of GH releasing factor (GRF) increased the release of 32P-phosphate labelled immunoprecipitable GH into the incubation media but not content of immunoprecipitable GH in the cells. The molecular weight of the phosphorylated immunoreactive cGH in the cells corresponded to cGH dimer.     

Resistance of tomato infected with cucumber mosaic virus satellite RNA to potato spindle tuber viroid

Tomato (Lycopersicon esculentum cvs Rutgers and Lichun) plants were firstly pre-inoculated either with a cucumber mosaic virus (CMV) isolate containing satellite RNA (CMV-S52) or with a CMV isolate without satellite RNA, and then challenged 14 days later with a severe strain of potato spindle tuber viroid (PSTVd). Also, tomato plants transformed with CMV satellite cDNA and non-transgenic control plants were directly inoculated with PSTVd. Protection effects were assessed by the observation of symptoms and by assay of PSTVd accumulation in tomato plants using return polyacrylamide gel electrophoresis and silver staining. The results indicated that the satellite-transgenic plants and plants pre-inoculated with CMV-S52 showed much milder symptoms of PSTVd infection than the respective control plants. The concentration of PSTVd RNA in the satellite-transgenic plants and CMV-S52 pre-inoculated plants was reduced to about 0.02-0.03 of the controls. PSTVd infection did not increase the amount of satellite ds-RNA in plants. It is concluded that the plant resistance to PSTVd is induced by the presence of satellite RNA rather than the CMV infection. It is suggested that as there is considerable sequence similarity between satellite RNA and PSTVd, base pairings may be a cause of reduction of both symptoms and the accumulation of PSTVd.     

Influence of thyroid hormone deficiency on the citrate synthase activity in rat brain regions during early postnatal development

The developmental pattern of citrate synthase activity has been studied in the liver and several brain areas of hypothyroid rats during the 4 first weeks of life. While citrate synthase activity in the liver showed a rise during the 2 first weeks of life, different patterns of enzyme activity were found in the brain regions of euthyroid animals. Citrate synthase activity increased in the cerebellum, decreased in the cerebral cortex and did not change significantly in the brain stem during the period studied. In the liver and brain areas, too, a decrease in citrate synthase activity was observed during hypothyroidism. From the 2nd week of birth, the citrate synthase activity in the brain but not in the liver was found to have recovered. The newly elevated citrate synthase activity coincided with a slight increase in thyroid hormone serum levels.     

Human granulocyte-specific nuclear antigen(s). II. Detection of antigens in human proliferative syndromes

Antisera raised to dehistonized chromatin from isolated normal human granulocytes revealed the presence of chromatin-associated antigens specific for the human neutrophils that appear during late stages of myeloid cellular differentiation. Immunological specificity was demonstrated by C fixation, immunodiffusion, and immunocytochemical reactions. Chromatin prepared from both normal granulocytes and specimens of myeloid leukemia showed immunologic reactivity. Although the normal antigens were detected in a specimen of CML, the position of immunodiffusion precipitin lines was different from that obtained with normal granulocyte chromatin. In addition, chromatin prepared from the myeloid leukemic cell line HL-60 expressed only one of the three precipitin bands normally found in immunodiffusion. The immunocytochemical staining reaction was confined to the nucleus of mature neutrophils in normal peripheral blood smears. Greater than 90% of cells in peripheral blood specimens of CML showed positive immunocytochemical nuclear staining. In other types of leukaemia, the normal mature granulocyte reacted with antiserum, but the nonmyeloid leukemic cells in these specimens did not. The specificity of immunologic reactions described here suggests the usefulness of nuclear antigens as cell markers.     

Characterization of human chromosomal DNA sequences which replicate autonomously in Saccharomyces cerevisiae.

We have characterised two restriction fragments, isolated from a "shotgun" collection of human DNA, which function as autonomously replicating sequences (ARSs) in Saccharomyces cerevisiae. Functional domains of these fragments have been defined by subcloning and exonuclease (BAL 31) deletion analysis. Both fragments contain two spatially distinct domains. One is essential for high frequency transformation and is termed the Replication Sequence (RS) domain, the other, termed the Replication Enhancer (RE) domain, has no inherent replication competence but is essential for ensuring maximum function of the RS domain. The nucleotide sequence of these domains reveals several conserved sequences one of which is strikingly similar to the yeast ARS consensus sequence.     

情前期与间情期大鼠内侧视前区-下丘脑前区神经元的电活动

在氯化筒箭毒制动的情前期及间情期大鼠上进行实验。用玻璃微电极记录内侧视前区-下丘脑前区(mPOA-AHA)的单位放电。mPOA-AHA 的大多数单位表现连续性或周期性自发放电。情前期大鼠周期性放电单位所占的百分比显著地多于间情期大鼠(P<0.01)。刺激子宫颈部可以使单位放电发生两种反应。一种单位对宫颈刺激发生放电频率增加的反应(宫颈兴奋神经元,CE 神经元),另一种单位则发生放电频率降低的反应(宫颈抑制神经元,CI神经元)。情前期大鼠 CE 与 CI 神经元所占的百分比与间情期大鼠没有明显的差异(P>0.05)。但情前期大鼠的 CE和 CI 神经元多呈现周期性放电,而间情期大鼠的 CE 和 CI 神经元则多呈现连续性放电。这说明 mPOA-AHA 神经元的电活动随生殖周期发生明显的变化。脑室注射去甲肾上腺素(NE)能使 mPOA-AHA 内大多数 CE 神经元对宫颈刺激的兴奋反应暂时受到抑制,而注射 NE 却使大多数 CI 神经元发生抑制解除。这些结果提示 NE 可能有抑制 CE 神经元和刺激 CI 神经元的作用。