Enhancement of the tolerance of Arabidopsis to high temperatures by genetic engineering of the synthesis of glycinebetaine

Arabidopsis thaliana was transformed with the codA gene for choline oxidase from Arthrobacter globiformis under control of the 35S RNA promoter of cauliflower mosaic virus. As a result, high levels of glycinebetaine accumulated in the seeds of transformed plants. Transformation with the codA gene significantly enhanced the tolerance to high temperatures during the imbibition and germination of seeds, as well as during growth of young seedlings. The extent of enhancement of the tolerance to high temperature was correlated with levels of choline oxidase expressed and of glycinebetine accumulated in the transformed plants. The induction of homologues of heat shock protein 70 at high temperature was less conspicuous in the transformed plants than in the wild-type plants, suggesting that the transformation alleviated the high-temperature stress.     

Polymorphism of the S -locus glycoprotein gene ( SLG ) and the S -locus related gene ( SLR1 ) in Raphanus sativus L. and self-incompatible ornamental plants in the Brassicaceae

The S-locus glycoprotein gene, SLG, which participates in the pollen-stigma interaction of self-incompatibility, and its unlinked homologue, SLR1, were analyzed in Raphanus sativus and three self-incompatible ornamental plants in the Brassicaceae. Among twenty-nine inbred lines of R. sativus, eighteen S haplotypes were identified on the basis of DNA polymorphisms detected by genomic Southern analysis using Brassica SLG probes. DNA fragments of SLG alleles specifically amplified from eight S haplotypes by PCR with class I SLG-specific primers showed different profiles following polyacrylamide gel electrophoresis, after digestion with a restriction endonuclease. The nucleotide sequences of the DNA fragments of these eight R. sativus SLG alleles were determined. Degrees of similarity of the nucleotide sequences to a Brassica SLG (S  ⁶ SLG) ranged from 85.6% to 91.9%. Amino acid sequences deduced from these had the twelve conserved cysteine residues and the three hypervariable regions characteristic of Brassica SLGs. Phylogenetic analysis of the SLG sequences from Raphanus and Brassica revealed that the Raphanus SLGs did not form an independent cluster, but were dispersed in the tree, clustering together with Brassica SLGs. These results suggest that diversification of the SLG alleles of Raphanus and Brassica occurred before differentiation of these genera. Although SLR1 sequences from Orychophragmus violaceus were shown to be relatively closely related to Brassica and Raphanus SLR1 sequences, DNA fragments that are highly homologous to the Brassica SLG were not detected in this species. Two other ornamental plants in the Brassicaceae, which are related more distantly to Brassica than Orychophragmus, also lacked sequences highly homologous to Brassica SLG genes. The evolution of self-incompatibility in the Brassicaceae is discussed. Received: 9 October 1997 / Accepted: 27 January 1998     

Vitamin E inhibits PGE2 and O2- production in rat peritoneal macrophages.

In order to examine the possible role of vitamin E on the modulation of macrophages, we investigated the effect of vitamin E on O2- and PGE2 production in macrophages. The production of both PGE2 and O2- in rat peritoneal macrophages was dose-dependently stimulated by the addition of PMA and calcium ionophore A23187. However, the macrophages obtained after intraperitoneal injection of vitamin E for six successive days showed less PGE2 and O2- production when stimulated with PMA or A23187 as compared to those of control macrophages. O2- production in control macrophages stimulated with 139 nM PMA and 1 microM A23187 as 4.2 +/- 0.3 and 3.0 +/- 0.2 nmol/min per 10(6) cells, respectively. On the other hand, O2- production by the macrophages from vitamin E-treated rats was 1.5 +/- 0.4 nmol/min per 10(6) cells when stimulated with the PMA, and was not detectable when stimulated with A23187. As for the production of PGE2, control macrophages produced 2.59 +/- 0.70 ng/30 min per 10(6) cells when stimulated with PMA and 8.96 +/- 3.26 ng/30 min per 10(6) cells with the A23187, whereas PGE2 production by the macrophages from vitamin E-treated rats was reduced to 12-20% of the control. By analyzing alpha-tocopherol content and intracellular concentration of calcium ion [( Ca2+]i) in the macrophages isolated from control and vitamin E-treated rats, vitamin E treatment augmented alpha-tocopherol content (384.7 +/- 76.1 vs. 1.2 +/- 0.4 ng/10(6) cells) and decreased free [Ca2+]i when stimulated with A23187 (652 +/- 14 vs. 1201 +/- 223 nM).     

Effector and regulatory cells in autoimmune oophoritis elicited by neonatal thymectomy.

(C57BL/6 x A/J)F1 (B6AF1) mice thymectomized between days 1 and 4 of age develop autoimmune oophoritis (D3TX oophoritis) 4 to 6 wk later. Oophoritis can be adoptively transferred to young recipients, and the disease in D3TX mice is prevented by reconstitution with normal adult spleen cells. The present study was further defined the nature of the effector and suppressor cells. Contrary to an earlier report, oophoritis is transferred to syngeneic and not allogeneic recipients. The spleen cells from D3TX mice when stimulated in vitro with Con A, also transfer oophoritis to adult recipients. The effector cells are CD4+: oophoritis transfer is abrogated by CD4 antibody and not by CD8 antibody and C. Spleen cells from D3TX male mice transfer disease less efficiently than female cells, thus endogenous ovarian Ag may be required for activation of effector T cells. T cells from normal adult spleen that suppress D3TX oophoritis also appear to be of CD4+ phenotype. These cells are likely to be derived from adult thymus because adult thymocytes also suppress D3TX disease. We were unable to substantiate the earlier claim that suppressor cells in normal mice are ovarian Ag specific. Thus male and female spleen cells suppress disease with comparable efficiency, and deprivation of endogenous ovarian Ag by neonatal ovariectomy of cell donors had no observable effect on disease suppression.     

Development of uterine adenomyosis after treatment with dopamine antagonists in mice

Development of uterine adenomyosis was studied in SHN mice treated with psychotherapeutic drugs, sulpiride and perphenazine, and gastroenteric drug, metoclopramide, which act as dopamine antagonists to increase prolactin release from the pituitary gland. Administration of these drugs twice daily for 40-70 or 40-90 days of age induced an elevation in serum level of prolactin. Furthermore, the treated mice showed a prolongation of metestrous plus diestrous phase and a high incidence of uterine adenomyosis compared with vehicle-treated control mice. These results indicate that hyperprolactinemia produced by continuous treatment with psychotherapeutic and gastroenteric drugs is responsible for the occurrence of irregular estrous cycles and the genesis of uterine adenomyosis in mice.