ABSTRACT
The conifer Larix olgensis has been analyzed to delineate physiological and proteomic changes that occur under drought stress. Studies of the deleterious effects of drought in the larch families have mainly focused on photosynthesis. In the present study, when the intensity of drought was increased, plant height was inhibited as both POD and MDA levels increased, which indicates oxidative stress. Two-dimensional gel electrophoresis analysis detected 23 significantly differentially expressed proteins, of which 18 were analyzed by peptide mass fingerprinting by using MALDI-TOF/TOF. Eight spots were found to be up-regulated, while the other 10 spots were down-regulated during drought stress. The proteins that were induced by drought treatment have been implicated in the physiological changes that occurred. These results could provide additional information that could lead to a better understanding of the molecular basis of drought-sensitivity in larch plants.
Subject(s)
Droughts , Larix/physiology , Proteomics , Stress, Physiological , Antioxidants/metabolism , Electrophoresis, Gel, Two-Dimensional , Lipid Peroxidation , Mass Spectrometry , Oxidative Stress , Proteome , Proteomics/methods , Quantitative Trait, HeritableABSTRACT
The chromosomes (2n = 2x = 24) of Larix principis-rupprechtii are composed of six pairs of large metacentrics and six pairs of medium-sized submetacentrics. The identification of homologous pairs is hampered by their high degree of similarity at the morphological level in each group. As one of the most extensively used methods in molecular cytogenetics producing chromosome landmarks, fluorescence in situ hybridization (FISH) has significantly facilitated karyotype construction, especially in species with morphologically similar chromosomes. This study developed a simple but effective use of combinatorial labeling probes to distinguish chromosomes of Larix principis-rupprechtii by multicolor FISH. Three highly repetitive sequences in Larix were selected: 25S rDNA hybridized at all of the secondary constrictions of two pairs of metacentrics and the largest pair of submetacentrics; 5S rDNA hybridized at subtelomeric sites of one pair of metacentrics that also harboured 25S rDNA on different arms; LPD family sequences are tandem repeats hybridized at proximal regions of 22 chromosomes. The three different probes were labeled with only two different labels, hybridized to metaphase chromosomes of Larix principis-rupprechtii, simultaneously visualized, and unequivocally distinguished in a single FISH experiment. These multicolor FISH marks largely improved the karyotype analysis of Larix principis-rupprechtii.
Subject(s)
Chromosome Mapping , In Situ Hybridization, Fluorescence/methods , Larix/genetics , Chromosomes, Plant/genetics , DNA, Ribosomal/genetics , Karyotyping , Larix/physiology , RNA, Plant/genetics , RNA, Ribosomal, 5S/geneticsABSTRACT
The chromosomes (2n = 2x = 24) of Larix principis-rupprechtii are composed of six pairs of large metacentrics and six pairs of medium-sized submetacentrics. The identification of homologous pairs is hampered by their high degree of similarity at the morphological level in each group. As one of the most extensively used methods in molecular cytogenetics producing chromosome landmarks, fluorescence in situ hybridization (FISH) has significantly facilitated karyotype construction, especially in species with morphologically similar chromosomes. This study developed a simple but effective use of combinatorial labeling probes to distinguish chromosomes of Larix principis-rupprechtii by multicolor FISH. Three highly repetitive sequences in Larix were selected: 25S rDNA hybridized at all of the secondary constrictions of two pairs of metacentrics and the largest pair of submetacentrics; 5S rDNA hybridized at subtelomeric sites of one pair of metacentrics that also harboured 25S rDNA on different arms; LPD family sequences are tandem repeats hybridized at proximal regions of 22 chromosomes. The three different probes were labeled with only two different labels, hybridized to metaphase chromosomes of Larix principis-rupprechtii, simultaneously visualized, and unequivocally distinguished in a single FISH experiment. These multicolor FISH marks largely improved the karyotype analysis of Larix principis-rupprechtii.