scholarly journals Activation of embryo during rape (Brassica napus L.) seed germination II. Transversal organisation of radicle apical meristem

2014 ◽  
Vol 49 (4) ◽  
pp. 387-395 ◽  
Author(s):  
Mieczysław Kuraś
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Cross Sections ◽  
Apical Meristem ◽  
Mature Embryo ◽  
Root Cap ◽  
Root Apical Meristem ◽  
Quiescent Centre ◽  
Brassica Napus L ◽  
Cell Patterns

Series of microtome cross sections of the root apical meristem were investigated in the mature embryo and young seedling of rape. The cell patterns are described in 3 layers of promeristem. Radial sectors of the root cap and protoderm, formed by common dermatocalyptrogen initials, and radial sectors of the cortex, produced by periblem initials were identified on all cross sections of the root. Between these sectors 4 segmentation boundaries of proembryo quadrants were distinguished, running across the whole root proper. The boundaries between the 4 sectors of connecting cells arising from the upper hypophysis derivative and the boundaries between the 4 sectors of the columella originating from the lower hypophysis derivative do not follow the same course and are not identical with the boundaries of the proembryo quadrants. Therefore during the whole embryogenesis, the central connecting cells, considered generally as cortex initials (iec), take no part in the development of the cortex but they form the quiescent centre of the radicle. Neither do the columella initial cells participate in the development of the lateral parts of the root cap.

scholarly journals Activation of embryo during rape (Brassica napus L.) seed germination. I. Structure of embryo and organization of root apical meristem

2015 ◽  
Vol 47 (1–2) ◽  
pp. 65-82 ◽  
Author(s):  
Miezcysław Kuraś
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Apical Meristem ◽  
Reference Points ◽  
Root Apical Meristem ◽  
Rape Seed ◽  
Brassica Napus L ◽  
Cell Patterns ◽  
Root Axis

The Structure of the mature rape embryo was examined on longitudirna microtome sections, and1, its developmental interpretation is given, based on the author's own studies and literature data. The boundaries between the epicotyl, hypocotyl and radicle are recognized and identified with the limits between the proembryo segments. The radicle Structure and root apical meristem organization are described. In the dermatogen and periblem cell patterns four segments are distinguished, separated successively from the initial cells. Their position is recognized as almost the same on both sides of the root axis and in different embryos. The easily discernible limits between the dermatogen sectors are to be utilized as reference points in studies on the root apical meristem activation and growth during rape seed germination.

scholarly journals Activation of rape (Brassica napus L.) embryo during seed germination. V. The first zones of ultrastructural changes and their expansion

2014 ◽  
Vol 56 (1) ◽  
pp. 77-91 ◽  
Author(s):  
Mieczysław Karaś
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Seed Coat ◽  
Basal Part ◽  
Ultrastructural Changes ◽  
Embryo Axis ◽  
Brassica Napus L ◽  
Root Cells ◽  
Basal Zone

In the germinating rape embryo the columella and basal part of hypocotyl undergo earliest activation. Its first ultrastructural symptom is the appearance of numerous ER vesicles after 3-6 h of seed swelling. Their number is the highest in the external layers of the columella and decreases in basipetal direction. Dermatogen cells in the basal zone of the hypocotyl contain the greatest amount of ER structures, whereas decreasing amounts are found in both directions along the embryo axis and centripetally. Further changes in the ER spread in a similar order. The vesicles merge and form a tubular and plate-like ER. Then, they disappear and are replaced by tubular and vesicular forms. The changes in the ER are gradually followed by ultrastructural symptoms of activation of mitochondria, plastids and dictyosomes. The highest number of ER structures and other organelles accumulate in root cells shortly before piercing of the seed coat. After germination their amount decreases and remains almost stable.

Primary vascular patterns in root meristems of Pontederia cordata and their relevance to studies of root development

1980 ◽  
Vol 58 (12) ◽  
pp. 1351-1369 ◽  
Author(s):  
W. A. Charlton
Keyword(s):  
Apical Meristem ◽  
Vascular System ◽  
Root Apex ◽  
Root Apical Meristem ◽  
Vascular Pattern ◽  
Quiescent Centre ◽  
Vascular Differentiation ◽  
Pontederia Cordata ◽  
Distribution Of Components ◽  
Root Apices

There are several files of metaxylem cells in root apices of Pontederia cordata L., each considered to consist of a series of prospective vessels with their ends in contact. Two longitudinally adjacent vessels may be in the same file of cells produced by the root apex or in adjacent files. As the root grows, successive prospective vessels are added to the apical ends of most of the files but not all files are continued. Addition of prospective vessels appears to take place within the "quiescent centre" of the root apical meristem. Where files are not continued there is no immediate readjustment of remaining files. The longitudinal and transverse distribution of components of the vascular system (including protophloem and protoxylem) is discussed in relation to the means by which the pattern of development may be controlled. Rates of production of vessels and the final lengths of the vessels are estimated. The observations and deductions are discussed in relation to other studies of root growth, vascular differentiation, and vascular pattern formation and maintenance.

scholarly journals Characterization of the BnA10.tfl1 Gene Controls Determinate Inflorescence Trait in Brassica napus L.

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 722 ◽  
Author(s):  
Yongpeng Jia ◽  
Kaixiang Li ◽  
Haidong Liu ◽  
Lingxiong Zan ◽  
Dezhi Du
Keyword(s):  
Brassica Napus ◽  
Shoot Apex ◽  
Apical Meristem ◽  
Brassica Napus L ◽  
Reading Frame ◽  
Terminal Flower ◽  
Terminal Flower 1 ◽  
Oilseed Breeding ◽  
Phosphatidylethanolamine Binding Protein

Determinate inflorescences have a significant effect on the genetic improvement of rapeseed, so understanding the molecular function underlying the inflorescence trait may be beneficial to oilseed breeding. A previous study found candidate gene BnTFL1 (Terminal Flower 1) for control of the inflorescence trait on Brassica napus chromosome A10 (16,627–16,847 kb). However, little is known about the function of the BnTFL1 gene in B. napus. In this study, we firstly studied the formation of the shoot apical meristem and gene expression in indeterminate and determinate inflorescences; the results showed that the inflorescence architecture and BnA10.TFL1 expression showed significant differences in the shoot apex at the budding stage. Then, two alleles (named BnA10.TFL1 gene from indeterminate and BnA10.tfl1 gene from determinate) were cloned and sequence-analyzed; the results suggest that the open reading frame of the alleles comprises 537 bp, encodes 178 amino acids containing a conserved phosphatidylethanolamine-binding protein (PEBP) domain, and shares high similarity with Arabidopsis thaliana TFL1. To analyze the function of BnA10.TFL1, the BnA10.TFL1 gene was introduced into the determinate A. thaliana tfl1 mutant and B. napus 571 line by complementation experiment. The determinate traits were restored to indeterminate, and expression of BnA10.TFL1 was increased in the indeterminate shoot apex. These results reveal that BnA10.tfl1 is a gene controlling the determinate inflorescence trait. Moreover, the BnA10.TFL1 protein was localized to the nucleus, cytoplasm, and plasma membrane. Collectively, the results of this study help us to understand the molecular mechanism of determinate inflorescences and will provide a reliable research basis for the application of determinate inflorescences in B. napus.

scholarly journals Cloning, Sequence Analysis and Expression Patterns during Seed Germination of a Rapeseed (Brassica napus L.) G-x-S-x-G-motif Lipase Gene

2016 ◽  
Vol 44 (2) ◽  
pp. 435-444
Author(s):  
Imen GLAIED GHRAM ◽  
Hatem BELGUITH ◽  
Maha BEN MUSTAPHA ◽  
Issam HIMILA ◽  
Balkiss BOUHAOUALA ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Seed Germination ◽  
Expression Patterns ◽  
Pcr Amplification ◽  
Gene Families ◽  
Lipase Gene ◽  
Homologous Proteins ◽  
Brassica Napus L ◽  
Calculated Molecular Mass ◽  
Hydrolysis Of

Lipases catalyze the hydrolysis of ester bonds in triacylglycerides, generating glycerol and free fatty acids. These enzymes are encoded by extremely complex gene families, and appear to fulfil many different biological functions. Although they are present in all types of organisms, available information on plant lipases is still very limited, as compared to their bacterial and animal counterparts. A full-length clone, BnLIP, encoding a putative lipase, has been isolated by PCR amplification of Brassica napus genomic DNA, with oligonucleotide primers derived from the sequence of an Arabidopsis thaliana homologue. The clone included an open reading frame of 1581 bp encoding a polypeptide of 526 amino acids, with a calculated molecular mass of 59.5 kDa. Analysis of the deduced protein sequence, sequence alignment with homologous proteins from related plant species, and a phylogenetic analysis revealed that the BnLIP protein belongs to the ‘classical’ GxSxG-motif lipase family. RT-PCR assays indicated that the BnLIP gene is expressed specifically, but only transiently, during seed germination: the lipase mRNA was not present at detectable levels in ungerminated seeds, was detected only three days after seed imbibition, but its levels decreased rapidly afterwards. No expression was observed in roots, stems or leaves of adult plants. This expression pattern suggests that BnLIP is one of the lipases involved in the hydrolysis of triacylglycerides stored in rapeseed seeds, ultimately providing nutrients and energy to sustain seedling growth until photosynthesis is activated.

scholarly journals Heat stress during seed filling interferes with sulfur restriction on grain composition and seed germination in oilseed rape (Brassica napus L.)

2015 ◽  
Vol 6 ◽  
Author(s):  
Sophie Brunel-Muguet ◽  
Philippe D'Hooghe ◽  
Marie-Paule Bataillé ◽  
Colette Larré ◽  
Tae-Hwan Kim ◽  
...  
Keyword(s):  
Heat Stress ◽  
Brassica Napus ◽  
Seed Germination ◽  
Oilseed Rape ◽  
Grain Composition ◽  
Brassica Napus L ◽  
Seed Filling
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