Physiological influences in the development and function of the shoot apical meristem of microspore-derived embryos of Brassica napus ‘Topas’

2006 ◽  
Vol 84 (3) ◽  
pp. 371-383 ◽  
Author(s):  
Nicole S. Ramesar-Fortner ◽  
Edward C. Yeung
Keyword(s):  
Brassica Napus ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Radial Symmetry ◽  
Brassica Napus L ◽  
Conversion Frequency ◽  
Dramatic Decline ◽  
Meristem Development ◽  
Methylpropionic Acid ◽  
And Function

The effect of auxins and abscisic acid (ABA) on shoot apical meristem development and function was analyzed in microspore-derived embryos of Brassica napus L. ‘Topas’. Embryos were treated with an auxin transport inhibitor, tri-iodobenzoic acid (TIBA) or exogenous indole-3-acetic acid (IAA) at various stages during their development. If embryos were treated at the preglobular or globular stages of embryogenesis, they developed one fused cotyledon indicating a continuation of radial symmetry. However, if treated later in development, embryos were comparable to the control and formed two separate cotyledons. To demonstrate that this was not a pharmacological effect, an auxin antagonist, 2-(p-chlorophenoxy)-2-methylpropionic acid, included with the TIBA treatment produced normal embryos with two separate cotyledons. Histological observations revealed that the shoot apical meristem of the embryos treated with TIBA or IAA at the preglobular and globular stages was altered. Preglobular and globular stage embryos that were treated with TIBA exhibited a dramatic decline in conversion frequency compared with their controls. Embryos that were treated later in development had conversion frequencies comparable to their controls, and their shoot apical meristems also were similar to controls. Application of ABA at the preglobular and globular stages maintained meristem integrity and improved embryo conversion. However, ABA could not reverse the TIBA effect.

Tri-iodobenzoic acid affects shoot apical meristem formation and function in zygotic embryos of Brassica napus cv. Topas

2001 ◽  
Vol 79 (3) ◽  
pp. 265-273
Author(s):  
Nicole S Ramesar-Fortner ◽  
Edward C Yeung
Keyword(s):  
Brassica Napus ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Bilateral Symmetry ◽  
Shoot Meristem ◽  
Zygotic Embryos ◽  
Brassica Napus L ◽  
Dramatic Decline ◽  
And Function ◽  
Iodobenzoic Acid

The effect of an auxin transport inhibitor, tri-iodobenzoic acid, on the formation and subsequent function of the shoot apical meristem in zygotic embryos of Brassica napus L. was examined. Globular and heart stage embryos were cultured in the presence of tri-iodobenzoic acid. Only embryos at the globular stage of embryogenesis were affected by tri-iodobenzoic acid. Upon treatment, the embryos did not develop two separate cotyledons and, therefore, did not attain bilateral symmetry. Furthermore, the shoot apical meristem of these embryos was altered, as a characteristic tunica-corpus organization was not observed. The cells of the surface layer continued to maintain their meristematic characteristics and divided mainly in the anticlinal direction. The subapical cells differentiated into parenchyma cells and continued to expand such that a corpus organization never developed. Therefore, by the end of the culture period, the shoot apical meristem appeared very broad and shallow. Treated embryos that were transferred to a conversion medium exhibited a dramatic decline and delay in the formation of leaves compared with untreated embryos. Histological observations revealed that the shoot apical meristem continued to expand in width. A low percentage of treated embryos were able to convert; however, leaves were produced from a new shoot meristem that developed in the axillary position. No morphological or histological changes were evident when the embryos were treated later, at the heart stage of embryogenesis.Key words: auxin, Brassica napus, embryo, shoot apical meristem, tri-iodobenzoic acid.

scholarly journals Regulation of Shoot Apical Meristem and Axillary Meristem Development in Plants

2020 ◽  
Vol 21 (8) ◽  
pp. 2917 ◽  
Author(s):  
Zhihui Xue ◽  
Liya Liu ◽  
Cui Zhang
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Recent Progress ◽  
Life Cycles ◽  
Axillary Meristem ◽  
Epigenetic Factors ◽  
Meristem Development ◽  
And Function ◽  
The Impact

Plants retain the ability to produce new organs throughout their life cycles. Continuous aboveground organogenesis is achieved by meristems, which are mainly organized, established, and maintained in the shoot apex and leaf axils. This paper will focus on reviewing the recent progress in understanding the regulation of shoot apical meristem and axillary meristem development. We discuss the genetics of plant meristems, the role of plant hormones and environmental factors in meristem development, and the impact of epigenetic factors on meristem organization and function.

scholarly journals Arabidopsis Argonaute10 Specifically Sequesters miR166/165 to Regulate Shoot Apical Meristem Development

Cell ◽  
2011 ◽  
Vol 145 (2) ◽  
pp. 242-256 ◽  
Author(s):  
Hongliang Zhu ◽  
Fuqu Hu ◽  
Ronghui Wang ◽  
Xin Zhou ◽  
Sing-Hoi Sze ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Meristem Development

scholarly journals Agronomic Performance and Flowering Behavior in Response to Photoperiod and Vernalization in Barley (Hordeum vulgare L.) Genotypes with Contrasting Drought Tolerance Behavior

2021 ◽  
Author(s):  
Jamal Abu-Elenein ◽  
Rabea Al-Sayaydeh ◽  
Zahera Akkeh ◽  
Zakaria Al-Ajlouni ◽  
AbdRaheem A. Al-Bawalize ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Agronomic Performance ◽  
Short Day ◽  
Drought Tolerant ◽  
Long Day ◽  
Meristem Development ◽  
Rainfed Conditions ◽  
Barley Genotypes

Abstract Background In barley, flowering behavior is a highly regulated and complex process where the appropriate matching of reproductive development with seasonal variation in water availability confer barley adaptation to different environments. In this study, the role of variation in flowering time and drought tolerance in four selected barley genotypes was studied under field and controlled conditions. For this purpose, field trials were conducted for two consecutive seasons at three diverse environments where the studied genotypes were subjected to either rainfed conditions or rainfed plus supplementary irrigation under two different sowing dates. Furthermore, reproductive meristem development in two selected barley genotypes, Rum (drought tolerant) and Steptoe (drought-sensitive) was also assessed in response to both vernalization and water stress under two different photoperiod conditions.Results Variation in the number of days to heading was more pronounced under rainfed conditions than under well water conditions. For agronomic performance, Rum was superior under all tested environments, which assure its general adaptability to multiple environments, while Steptoe was the poorest. The transition to reproductive meristem was faster under vernalized long-day conditions as compared to vernalized short-day conditions. The progress of shoot apical meristem development and heading under long-day conditions was significantly faster in Rum than that of Steptoe. A clear effect of drought stress was observed on shoot apical meristem development in Steptoe. Under short-day conditions, vernalized Rum plants subjected to water deficit showed an advanced meristem development stage a significant earlier HD when compared with non-stressed plants. This early flowering behavior in stressed Rum plants under short-day conditions was accompanied by higher gene expression of the Vrn-H1 gene. Conclusion In conclusion, the integration of vernalization and photoperiod signals in drought-tolerant barley genotypes is associated with early flowering behavior and higher productivity in dry environments.

Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 397-403 ◽  
Author(s):  
H. M. Ottoline Leyser ◽  
I. J. Furner
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Growth ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Development ◽  
Wild Type ◽  
Recessive Mutations ◽  
Phenotypic Characterisation ◽  
Dicotyledonous Plants ◽  
And Function

The shoot apical meristem of dicotyledonous plants is highly regulated both structurally and functionally, but little is known about the mechanisms involved in this regulation. Here we describe the genetic and phenotypic characterisation of recessive mutations at three loci of Arabidopsis thaliana in which meristem structure and function are disrupted. The loci are Clavata1 (Clv1), Fasciata1 (Fas1) and Fasciata2 (Fas2). Plants mutant at these loci are fasciated having broad, flat stems and disrupted phyllotaxy. In all cases, the fasciations are associated with shoot apical meristem enlargement and altered floral development. While all the mutants share some phenotypic features they can be divided into two classes. The pleiotropic fas1 and fas2 mutants are unable to initiate wild- type organs, show major alterations in meristem structure and have reduced root growth. In contrast, clv1 mutant plants show near wild-type organ phenotypes, more subtle changes in shoot apical meristem structure and wild-type root growth.

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.

Sign in / Sign up

Export Citation Format

Share Document