DEVELOPMENTAL MORPHOLOGY OF THE ROOT OF SELAGINELLA MARTENSII SPRING

1967 ◽  
Vol 45 (4) ◽  
pp. 395-404 ◽  
Author(s):  
T. R. Webster ◽  
T. A. Steeves
Keyword(s):  
Root Development ◽  
Root Hair ◽  
Apical Meristem ◽  
Root Cap ◽  
Root Initiation ◽  
Developmental Morphology ◽  
Root Hair Formation ◽  
Hair Formation

The origin and development of the root of Selaginella martensii have been investigated. The roots arise from angle-meristems situated at each branching of the stem. A ventral angle-meristem is present at each forking, and at some forkings a corresponding dorsal angle-meristem is also present. As the root grows through its aerial length (several centimeters), the tip undergoes bifurcation and a root cap is lacking. When the tip nears the soil, a cap is formed by distal segmentation of cells in the apical meristem. Externally visible branching and root hair formation usually occur soon after a cap is formed. The observations of root development in S. martensii agree in general with observations previously made on S. densa, S. wallacei, and S. kraussiana. No evidence for a “rhizophore” or endogenous root initiation as described previously by others has been found. The results are discussed in the light of the concept of a “rhizophore” in Selaginella.

scholarly journals Alternative Oxidase Inhibition Impairs Tobacco Root Development and Root Hair Formation

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Liu ◽  
Lu-Lu Yu ◽  
Ye Peng ◽  
Xin-Xin Geng ◽  
Fei Xu
Keyword(s):  
Gene Expression ◽  
Root Development ◽  
Transcriptome Analysis ◽  
Root Hair ◽  
Alternative Oxidase ◽  
Regulation Of Gene Expression ◽  
Main Root ◽  
Respiratory Pathway ◽  
Root Hair Formation ◽  
Hair Formation

Alternative oxidase (AOX) is the terminal oxidase of the mitochondrial respiratory electron transport chain in plant cells and is critical for the balance of mitochondrial hemostasis. In this study, the effect of inhibition of AOX with different concentrations of salicylhydroxamic acid (SHAM) on the tobacco root development was investigated. We show here that AOX inhibition significantly impaired the development of the main root and root hair formation of tobacco. The length of the main root of SHAM-treated tobacco was significantly shorter than that of the control, and no root hairs were formed after treatment with a concentration of 1 mM SHAM or more. The transcriptome analysis showed that AOX inhibition by 1 mM SHAM involved in the regulation of gene expression related to root architecture. A total of 5,855 differentially expressed genes (DEGs) were obtained by comparing SHAM-treated roots with control. Of these, the gene expression related to auxin biosynthesis and perception were significantly downregulated by 1 mM SHAM. Similarly, genes related to cell wall loosening, cell cycle, and root meristem growth factor 1 (RGF1) also showed downregulation on SHAM treatment. Moreover, combined with the results of physiological measurements, the transcriptome analysis demonstrated that AOX inhibition resulted in excessive accumulation of reactive oxygen species in roots, which further induced oxidative damage and cell apoptosis. It is worth noting that when indoleacetic acid (20 nM) and dimethylthiourea (10 mM) were added to the medium containing SHAM, the defects of tobacco root development were alleviated, but to a limited extent. Together, these findings indicated that AOX-mediated respiratory pathway plays a crucial role in the tobacco root development, including root hair formation.

Integrated analysis of plant gene expression and bacterial and protozoan community composition reveals changes related to root zonation, root cap and root hair formation

2021 ◽  
Author(s):  
Minh Ganther ◽  
Lioba Rüger ◽  
Michael Bonkowski ◽  
Anna Heintz-Buschart ◽  
Mika Tarkka
Keyword(s):  
Gene Expression ◽  
Microbial Communities ◽  
Root Hair ◽  
Root Cap ◽  
Integrated Analysis ◽  
Root Interactions ◽  
Protozoan Community ◽  
Root Hair Formation ◽  
Root Gene Expression ◽  
Hair Formation

<p>This study was conducted within the framework of the DFG project SPP2089 “Rhizosphere Spatiotemporal Organization – a Key to Rhizosphere Functions” (project number 403641192).</p><p>As plant roots grow into the soil, the formation of biological gradients occurs at different spatial scales. It has been shown that plants recruit specific subsets of the soil bacterial community at their roots through excretion of mucilage at root tips and exudates at the sites of root hair formation. The promotion of or defense against certain bacterial taxa is also reflected in the composition of the protist communities that feed on bacteria.</p><p>Using high-throughput sequencing methods, we investigated emerging patterns in root gene expression in relation to bacterial and protozoan community structures. We found highly distinct root region specific patterns relating to differential root gene expression relating to growth, defense and transporter activity, as well as bacterial and protist (cercozoan) diversity. Root cap removal led to differently composed microbial communities, as well as a regulation of root genes relating to stress and defense. The lack of root hairs was only reflected in the amount of microbial carbon in soil and a small number of differentially expressed genes involved in cell wall processes.</p><p>We could show that the rhizosphere microbiome, is as dynamic as its environment. Root regions differentially affect microbial communities, which is also reflected in the expression of plant genes of categories relating to defense, immunity and stress. Our findings will further enhance our understanding of microbial root interactions at single root scale.</p>

Differential expression of ACC oxidase genes during low-pH-induced root hair formation in lettuce (Lactuca sativa L.) seedlings

2010 ◽  
Vol 62 (2) ◽  
pp. 137-149 ◽  
Author(s):  
Hidenori Takahashi ◽  
Testuhito Shinkawa ◽  
Shinjiro Nakai ◽  
Yasunori Inoue
Keyword(s):  
Differential Expression ◽  
Lactuca Sativa ◽  
Root Hair ◽  
Acc Oxidase ◽  
Low Ph ◽  
Lactuca Sativa L ◽  
Root Hair Formation ◽  
Hair Formation

scholarly journals Molecular Cloning and Characterization of β-Expansin Gene Related to Root Hair Formation in Barley

2006 ◽  
Vol 141 (3) ◽  
pp. 1149-1158 ◽  
Author(s):  
Miroslaw Kwasniewski ◽  
Iwona Szarejko
Keyword(s):  
Molecular Cloning ◽  
Root Hair ◽  
Expansin Gene ◽  
Root Hair Formation ◽  
Hair Formation

Root hair formation and elongation of primary maize roots

1986 ◽  
Vol 68 (4) ◽  
pp. 653-656 ◽  
Author(s):  
Francoise Jaunin ◽  
Rose-Marie Hofer
Keyword(s):  
Root Hair ◽  
Maize Roots ◽  
Root Hair Formation ◽  
Hair Formation

Role of manganese in low-pH-induced root hair formation in Lactuca sativa cv. Grand Rapids seedlings

2003 ◽  
Vol 116 (4) ◽  
pp. 301-307 ◽  
Author(s):  
Masae Konno ◽  
Machiko Ooishi ◽  
Yasunori Inoue
Keyword(s):  
Lactuca Sativa ◽  
Root Hair ◽  
Low Ph ◽  
Grand Rapids ◽  
Root Hair Formation ◽  
Hair Formation

Molecular mapping of genes involved in root hair formation in barley

Euphytica ◽  
2007 ◽  
Vol 157 (1-2) ◽  
pp. 95-111 ◽  
Author(s):  
Agnieszka Janiak ◽  
Iwona Szarejko
Keyword(s):  
Root Hair ◽  
Molecular Mapping ◽  
Root Hair Formation ◽  
Hair Formation

scholarly journals Mitochondrial β-Cyanoalanine Synthase Is Essential for Root Hair Formation in Arabidopsis thaliana

2010 ◽  
Vol 22 (10) ◽  
pp. 3268-3279 ◽  
Author(s):  
Irene García ◽  
José María Castellano ◽  
Blanca Vioque ◽  
Roberto Solano ◽  
Cecilia Gotor ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Hair ◽  
Root Hair Formation ◽  
Cyanoalanine Synthase ◽  
Hair Formation
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