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1.
Plant Physiol ; 118(4): 1495-506, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9847126

ABSTRACT

Alfalfa (Medicago sativa L.) roots contain large quantities of beta-amylase, but little is known about its role in vivo. We studied this by isolating a beta-amylase cDNA and by examining signals that affect its expression. The beta-amylase cDNA encoded a 55.95-kD polypeptide with a deduced amino acid sequence showing high similarity to other plant beta-amylases. Starch concentrations, beta-amylase activities, and beta-amylase mRNA levels were measured in roots of alfalfa after defoliation, in suspension-cultured cells incubated in sucrose-rich or -deprived media, and in roots of cold-acclimated germ plasms. Starch levels, beta-amylase activities, and beta-amylase transcripts were reduced significantly in roots of defoliated plants and in sucrose-deprived cell cultures. beta-Amylase transcript was high in roots of intact plants but could not be detected 2 to 8 d after defoliation. beta-Amylase transcript levels increased in roots between September and October and then declined 10-fold in November and December after shoots were killed by frost. Alfalfa roots contain greater beta-amylase transcript levels compared with roots of sweetclover (Melilotus officinalis L.), red clover (Trifolium pratense L.), and birdsfoot trefoil (Lotus corniculatus L.). Southern analysis indicated that beta-amylase is present as a multigene family in alfalfa. Our results show no clear association between beta-amylase activity or transcript abundance and starch hydrolysis in alfalfa roots. The great abundance of beta-amylase and its unexpected patterns of gene expression and protein accumulation support our current belief that this protein serves a storage function in roots of this perennial species.


Subject(s)
Medicago sativa/enzymology , Medicago sativa/genetics , beta-Amylase/genetics , beta-Amylase/metabolism , Amino Acid Sequence , Base Sequence , DNA Primers/genetics , DNA, Complementary/genetics , DNA, Plant/genetics , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Genes, Plant , Molecular Sequence Data , Multigene Family , Plant Roots/enzymology , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Plant/genetics , RNA, Plant/metabolism , Sequence Homology, Amino Acid , Starch/metabolism , Sucrose/metabolism
2.
Plant Mol Biol ; 34(4): 643-50, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9247545

ABSTRACT

The low-temperature (2 degrees C)-specific wheat cDNA, pTACR7, represents a gene designated tacr7 from hard red winter wheat (HRWW; Triticum aestivum L. cv. Winoka). The term low-temperature-specific (LTS) is used because tacr7 is not induced by ABA or stresses such as salt, dehydration, and heat. pTACR7 was isolated by RT-PCR with mRNA from wheat crown tissue, the oligonucleotide primers derived from the barley cognate pHVCR8 (GenBank accession number L28091). Based on the deduced amino acid sequence, TACR7 is highly hydrophobic, with a single transmembrane domain and an amino acid bias for leucine (19%). Thus, the encoded protein TACR7 is unique among low-temperature-regulated wheat proteins described in the literature. Analysis of steady-state levels of tacr7 transcripts (630 nt) showed accumulation in wheat seedlings, crown tissue, and callus cultures after transfer from control (25 degrees C) to low temperature (2 degrees C). No detectable transcripts were observed by northern blot hybridization with pTACR7 probe from seedling or callus treated with ABA, salt, dehydration, or heat stress. tacr7 transcripts accumulated during 2 degrees C exposure to a greater amount in a freeze-resistant HRWW (FR; SDmut 16029) than in a freeze-susceptible HRWW (FS; SDmut 16169) crown tissue, with the largest difference between genotypes being 30% +/- 3% at 3 weeks.


Subject(s)
Gene Expression Regulation, Plant , Genes, Plant , Plant Proteins/genetics , Triticum/genetics , Abscisic Acid/pharmacology , Amino Acid Sequence , Cells, Cultured , DNA, Complementary/genetics , Freezing , Molecular Sequence Data , Mutation , Plant Proteins/biosynthesis , Plant Shoots/cytology , Plant Shoots/genetics , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA, Plant/biosynthesis , RNA, Plant/genetics , Seasons , Sequence Homology, Amino Acid , Species Specificity , Triticum/cytology
3.
Rev Chil Obstet Ginecol ; 58(5): 374-80, 1993.
Article in Spanish | MEDLINE | ID: mdl-7991859

ABSTRACT

Thirty one patients with clinical and sonographic diagnosis of ovarian tumor were studied prospectively, with Transvaginal Color Doppler. There were 24 benign and 7 malignant tumors (4 stage I borderline, I stage IA cistoadenocarcinoma and 2 adenocarcinoma stage III). Six malignant tumors had resistance indexes (IR) from 0.17 to 0.55. In one borderline no vascular signal was obtained. The probability of malignancy increased inversely with the IR from 60%, with RI below 0.60 to 100% with IR below 0.4.


Subject(s)
Adenocarcinoma/diagnostic imaging , Cystadenocarcinoma/diagnostic imaging , Ovarian Neoplasms/diagnostic imaging , Adenocarcinoma/pathology , Adult , Aged , Cystadenocarcinoma/pathology , Female , Humans , Middle Aged , Neoplasm Staging , Ovarian Neoplasms/pathology , Prospective Studies , Ultrasonography
4.
Rev Chil Obstet Ginecol ; 57(1): 27-9, 1992.
Article in Spanish | MEDLINE | ID: mdl-1342424

ABSTRACT

Two cases of pelvic collections of different etiology, admitted in the isolation unit of the Gynecology and Obstetrics Department of Hospital del Salvador are presented. Both were resolved by means of ultrasound transabdominal puncture, the first a tubo-ovarian abscess, in which there was placed a percutaneous drainage, and the second, a Residual Lutein Cyst, (Subsequent' to an Ectopic Pregnancy resolved by surgery) by means only of punction. In the first case (tubo-ovarian abscess) the patient became pregnant 2 months after de punction having actually a physiologic evolution. In the second case the patient is asymptomatic and has normal medical controls.


Subject(s)
Abscess/diagnostic imaging , Ovarian Cysts/diagnostic imaging , Abscess/therapy , Adult , Anti-Bacterial Agents , Combined Modality Therapy , Drainage , Drug Therapy, Combination/therapeutic use , Female , Humans , Ovarian Cysts/therapy , Ovary/diagnostic imaging , Pelvis , Punctures , Ultrasonography
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