The role of the monopteros gene in organising the basal body region of the Arabidopsis embryo

The monopteros (mp) gene contributes to apical-basal pattern formation in the Arabidopsis embryo. mp mutant seedlings lack basal body structures such as hypocotyl, radicle and root meristem, and this pattern deletion has been traced back to alterations in the octant-stage embryo. Cells of the embryo proper and the uppermost cell of the suspensor fail to establish division patterns that would normally generate the basal body structures. The resulting absence of a morphological axis seems to be responsible for another phenotypic trait of mp seedlings, variable positioning of cotyledons. This relationship is suggested by weak mp seedling phenotypes in which the presence of a short hypocotyl is correlated with normal arrangement of cotyledons. Root formation has been induced in mp seedlings grown in tissue culture. This result supports the notion that the mp gene is required for organising the basal body region, rather than for making the root, in the developing embryo.

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Apical-basal pattern formation in the Arabidopsis embryo: studies on the role of the gnom gene

Development ◽

10.1242/dev.117.1.149 ◽

1993 ◽

Vol 117 (1) ◽

pp. 149-162 ◽

Cited By ~ 14

Author(s):

U. Mayer ◽

G. Buttner ◽

G. Jurgens

Keyword(s):

Pattern Formation ◽

Root Formation ◽

Asymmetric Cell Division ◽

Early Embryo ◽

The Body ◽

Wild Type ◽

Early Effect ◽

Normal Number ◽

Mutant Seedling

gnom is one of several genes that make substantial contributions to pattern formation along the apical-basal axis of polarity in the Arabidopsis embryo as indicated by the mutant seedling phenotype. The apical and basal end regions of the body pattern, which include the meristems of the shoot and the root, fail to form, and a minority of mutant embryos lack morphological features of apical-basal polarity. We have investigated the developmental basis of the gnom mutant phenotype, taking advantage of a large number of EMS-induced mutant alleles. The seedling phenotype has been traced back to the early embryo in which the asymmetric division of the zygote is altered, now producing two nearly equal-sized cells. The apical daughter cell then undergoes abnormal divisions, resulting in an octant embryo with about twice the normal number of cells while the uppermost derivative of the basal cell fails to become the hypophysis, which normally contributes to root development. Consistent with this early effect, gnom appears to be epistatic to monopteros in doubly mutant embryos, suggesting that, without prior gnom activity, the monopteros gene cannot promote root and hypocotyl development. On the other hand, when root formation was induced in bisected seedlings, wild-type responded whereas gnom mutants failed to produce a root but formed callus instead. These results suggest that gnom activity promotes asymmetric cell division which we believe is necessary both for apical-basal pattern formation in the early embryo and for root formation in tissue culture.

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The role of the monopteros gene in organising the basal body region of the Arabidopsis embryos

Trends in Genetics ◽

10.1016/0168-9525(93)90246-e ◽

1993 ◽

Vol 9 (9) ◽

pp. 299 ◽

Cited By ~ 5

Keyword(s):

Basal Body ◽

Body Region

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Microbial Biofilms and Biotechnology – Some Perceptions

Current Biotechnology ◽

10.2174/2211550109999201026091512 ◽

2020 ◽

Vol 09 ◽

Author(s):

Subba Rao Toleti

Keyword(s):

Tissue Culture ◽

Synthetic Biology ◽

Industrial Effluents ◽

Aquatic Environments ◽

Biochemical Processes ◽

Microbial Biofilms ◽

Biofilm Bacteria ◽

Prophylactic Vaccines ◽

Design Construction

: The review is an attempt to introduce the readers in brief about biofilms and their implications as well as some new perceptions in biotechnology. Biofilms are adherent microbial communities, which are developed on submerged surfaces in aquatic environments. Biofilms play a significant role in exopolymer production, material deterioration and also cause harmful infections. Further, the role of corrosion causing biofilm bacteria in deterioration of different materials, microbial biofilms and their enzymatic processes in reducing the toxicity of pollutants in industrial effluents are elaborated, along with clean technologies for wastewater treatment. Biotechnology is defined as any technological application that uses biological systems to synthesize or modify products or processes. The applications include biochemical processes, medical care, cell and tissue culture as well as synthetic biology and others. Synthetic biology details about the design, construction of new biological components and systems for useful purposes. Finally, to overcome the limitations that are inherent to the use of cellular host’s, cell-free systems as critical platforms for synthetic biology applications. This mini-review also mentions about new diagnostic products based on enzymes, monoclonal antibodies and engineered proteins as well as novel prophylactic vaccines.

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Role of Humoral Antibody and Infecting Dose in the Recovery of Rous Sarcoma Virus From Turkey Tumor Cells in Tissue Culture2

JNCI Journal of the National Cancer Institute ◽

10.1093/jnci/29.4.739 ◽

1962 ◽

Keyword(s):

Tissue Culture ◽

Tumor Cells ◽

Rous Sarcoma Virus ◽

Humoral Antibody ◽

Rous Sarcoma ◽

Sarcoma Virus

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The role of JrPPOs in the browning of walnut explants

BMC Plant Biology ◽

10.1186/s12870-020-02768-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Shugang Zhao ◽

Hongxia Wang ◽

Kai Liu ◽

Linqing Li ◽

Jinbing Yang ◽

...

Keyword(s):

Tissue Culture ◽

Production Efficiency ◽

Phenolic Content ◽

Leaf Tissue ◽

Limiting Factor ◽

Mature Leaves ◽

Survival Percentage ◽

Highly Active ◽

Young Leaves

Abstract Background Tissue culture is an effective method for the rapid breeding of seedlings and improving production efficiency, but explant browning is a key limiting factor of walnut tissue culture. Specifically, the polymerization of PPO-derived quinones that cause explant browning of walnut is not well understood. This study investigated explants of ‘Zanmei’ walnut shoot apices cultured in agar (A) or vermiculite (V) media, and the survival percentage, changes in phenolic content, POD and PPO activity, and JrPPO expression in explants were studied to determine the role of PPO in the browning of walnut explants. Results The results showed that the V media greatly reduced the death rate of explants, and 89.9 and 38.7% of the explants cultured in V media and A media survived, respectively. Compared with that of explants at 0 h, the PPO of explants cultured in A was highly active throughout the culture, but activity in those cultured in V remained low. The phenolic level of explants cultured in A increased significantly at 72 h but subsequently declined, and the content in the explants cultured in V increased to a high level only at 144 h. The POD in explants cultured in V showed high activity that did not cause browning. Gene expression assays showed that the expression of JrPPO1 was downregulated in explants cultured in both A and V. However, the expression of JrPPO2 was upregulated in explants cultured in A throughout the culture and upregulated in V at 144 h. JrPPO expression analyses in different tissues showed that JrPPO1 was highly expressed in stems, young leaves, mature leaves, catkins, pistils, and hulls, and JrPPO2 was highly expressed in mature leaves and pistils. Moreover, browning assays showed that both explants in A and leaf tissue exhibited high JrPPO2 activity. Conclusion The rapid increase in phenolic content caused the browning and death of explants. V media delayed the rapid accumulation of phenolic compounds in walnut explants in the short term, which significantly decreased explants mortality. The results suggest that JrPPO2 plays a key role in the oxidation of phenols in explants after branch injury.

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