ABSTRACT
In this work, the population of small RNAs (sRNAs) was studied in the gymnosperm Sequoia sempervirens during phase changes, specifically in the juvenile, adult and rejuvenated plants obtained in vitro. The potential target genes of Sequoia sRNAs were predicted through bioinformatics. Rejuvenation is a pivotal process in woody plants that enables them to regain their growth potential, which results in the recovery of physiologic and molecular characteristics that were lost when the juveniles mature into adult plants. The results from the five repeated graftings of juvenile, adult and rejuvenated plants in vitro showed that sRNAs could be classified into structural RNAs (Group I), small interfering RNAs (Group II), annotated microRNAs (Group III, and unannotated sRNAs (Group IV). The results indicate that only 573 among 15,485,415 sRNAs (Groups III and IV) had significantly different expression patterns associated with rejuvenation and phase change. A total of 215 sRNAs exhibited up-regulated expression patterns in adult shoots, and 358 sRNAs were down-regulated. Expression profiling and prediction of possible target genes of these unique small RNAs indicate possible functions in the control of photosynthetic efficiency and rooting competence abundance during plant rejuvenation. Moreover, the increase in SsmiR156 and decrease in SsmiR172 during plant rejuvenation suggested that these two microRNAs extensively affect phase transition.
Subject(s)
Gene Expression Regulation, Developmental/genetics , Plant Proteins/genetics , RNA, Plant/genetics , Sequoia/growth & development , Sequoia/genetics , Abscisic Acid/analysis , Abscisic Acid/metabolism , Biomass , Computational Biology , Epigenomics , Gene Expression Profiling , Gene Expression Regulation, Plant/genetics , Gene Library , High-Throughput Nucleotide Sequencing , MicroRNAs/genetics , MicroRNAs/metabolism , Molecular Sequence Annotation , Plant Growth Regulators/analysis , Plant Growth Regulators/metabolism , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Leaves/physiology , Plant Roots/genetics , Plant Roots/growth & development , Plant Roots/physiology , Plant Shoots/genetics , Plant Shoots/growth & development , Plant Shoots/physiology , Plant Stems/genetics , Plant Stems/growth & development , Plant Stems/physiology , RNA, Plant/metabolism , RNA, Small Interfering/genetics , Sequoia/physiology , Up-Regulation/geneticsABSTRACT
Unlike other plants, bamboo (Bambusoideae) flowering is an elusive physiological phenomena, because it is unpredictable, long-periodic, gregarious, and uncontrollable; also, bamboo plants usually die after flowering. The flowering mechanism in Arabidopsis thaliana, a eudicot model species, is well established, but it remains unknown in bamboo species. We found 4470 and 3878 expressed sequence tags in the flower bud and vegetative shoot cDNA libraries, respectively, of the bamboo species, Bambusa oldhamii. Different genes were found expressed in bamboo flower buds compared to vegetative shoots, based on the Munich Information Center for Protein Sequences functional categorization; flowering-related genes were also identified in this species. We also identified Arabidopsis flowering-specific homologs that are involved in its photoperiod in this bamboo species, along with autonomous, vernalization and gibberellin-dependent pathways, indicating that bamboos may have a similar mechanism to control floral transition. Some bamboo expressed sequence tags shared high similarity with those of rice, but others did not match any known sequences. Our data lead us to conclude that bamboo may have its own unique flowering genes. This information can help us understand bamboo flowering and provides useful experimental methods to study the mechanisms involved.
Subject(s)
Bambusa/genetics , Expressed Sequence Tags , Flowers/genetics , Arabidopsis/genetics , Crosses, Genetic , DNA, Complementary/metabolism , Gene Library , Genes, Plant , Models, Genetic , Oryza/genetics , Plant Shoots , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Brown bowel syndrome is a rare intestinal disorder associated with the deposition of lipofuscin pigment in the smooth muscle cells. We report two such cases presenting with intestinal pseudo-obstruction, abdominal pain, and body weight loss. Both cases had malabsorption and fatty liver. Exploratory laparotomy revealed brownish discoloration of the small bowel wall and enlargement of mesenteric lymph nodes. Light microscopy, autofluorescence and ultrastructure studies confirmed the deposition of lipofuscin pigments in the intestinal muscle cells and reticuloendothelial cells of mesenteric lymph nodes. In addition, the calf muscle biopsy of case 1 displayed myopathy and fatty replacement. Skeletal muscle strength of both patients was partially restored after parenteral and oral vitamin E supplement and other conservative treatment, but gastrointestinal symptoms of both patients continued to deteriorate. Thus, brown bowel syndrome associated with prolonged and severe malnutrition and possibly vitamin E deficiency appears only partially responsive to vitamin E supplementation.