Phloem and Xylem Differentiation

2021 ◽  
pp. 101-130
Author(s):  
Roni Aloni
Keyword(s):  
Xylem Differentiation

scholarly journals Effect of Exogenously Applied 24-Epibrassinolide and Brassinazole on Xylogenesis and Microdistribution of Cell Wall Polymers in Leucaena leucocephala (Lam) De Wit

2021 ◽  
Author(s):  
S. Pramod ◽  
M. Anju ◽  
H. Rajesh ◽  
A. Thulaseedharan ◽  
Karumanchi S. Rao
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Leucaena Leucocephala ◽  
Higher Plants ◽  
Lignin Content ◽  
Wood Quality ◽  
Wall Structure ◽  
Vessel Element ◽  
Xylem Differentiation ◽  
Cell Wall Polymers

AbstractPlant growth regulators play a key role in cell wall structure and chemistry of woody plants. Understanding of these regulatory signals is important in advanced research on wood quality improvement in trees. The present study is aimed to investigate the influence of exogenous application of 24-epibrassinolide (EBR) and brassinosteroid inhibitor, brassinazole (BRZ) on wood formation and spatial distribution of cell wall polymers in the xylem tissue of Leucaena leucocephala using light and immuno electron microscopy methods. Brassinazole caused a decrease in cambial activity, xylem differentiation, length and width of fibres, vessel element width and radial extent of xylem suggesting brassinosteroid inhibition has a concomitant impact on cell elongation, expansion and secondary wall deposition. Histochemical studies of 24-epibrassinolide treated plants showed an increase in syringyl lignin content in the xylem cell walls. Fluorescence microscopy and transmission electron microscopy studies revealed the inhomogenous pattern of lignin distribution in the cell corners and middle lamellae region of BRZ treated plants. Immunolocalization studies using LM10 and LM 11 antibodies have shown a drastic change in the micro-distribution pattern of less substituted and highly substituted xylans in the xylem fibres of plants treated with EBR and BRZ. In conclusion, present study demonstrates an important role of brassinosteroid in plant development through regulating xylogenesis and cell wall chemistry in higher plants.

The Effect of NaCl on Growth and Xylem Differentiation of Radish Seedlings

1990 ◽  
Vol 151 (4) ◽  
pp. 516-521 ◽  
Author(s):  
A. Scialabba ◽  
M. R. Melati
Keyword(s):  
Xylem Differentiation ◽  
Radish Seedlings

Decrease of polygalacturonic acid synthase during xylem differentiation in sycamore

1985 ◽  
Vol 24 (4) ◽  
pp. 699-702 ◽  
Author(s):  
G.P. Bolwell ◽  
G. Dalessandro ◽  
D.H. Northcote
Keyword(s):  
Xylem Differentiation ◽  
Polygalacturonic Acid

scholarly journals Chemical control of xylem differentiation by thermospermine, xylemin and auxin

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Kaori Yoshimoto ◽  
Hiroyoshi Takamura ◽  
Isao Kadota ◽  
Hiroyasu Motose ◽  
Taku Takahashi
Keyword(s):  
Chemical Control ◽  
Xylem Differentiation

scholarly journals EFFECTOR OF TRANSCRIPTION2 is involved in xylem differentiation and includes a functional DNA single strand cutting domain

2008 ◽  
Vol 313 (1) ◽  
pp. 93-106 ◽  
Author(s):  
Rumen Ivanov ◽  
Jens Tiedemann ◽  
Andreas Czihal ◽  
Anna Schallau ◽  
Le Hong Diep ◽  
...  
Keyword(s):  
Single Strand ◽  
Xylem Differentiation ◽  
Functional Dna

Effect of polar auxin transport and gibberellins on xylem formation in pine cuttings under adventitious rooting conditions

2020 ◽  
Vol 67 (1-2) ◽  
pp. 27-39 ◽  
Author(s):  
Alberto Pizarro ◽  
Carmen Díaz-Sala
Keyword(s):  
Adventitious Root ◽  
Root Formation ◽  
Auxin Transport ◽  
Adventitious Rooting ◽  
Adventitious Root Formation ◽  
Polar Auxin Transport ◽  
Root Induction ◽  
Xylem Differentiation ◽  
Xylem Formation ◽  
Hypocotyl Cuttings

Maturation-related decline of adventitious root formation is one of the major factors affecting adventitious rooting in forest tree species. We demonstrate that inhibition of polar auxin transport promoted cambium and xylem differentiation in rooting-competent hypocotyl cuttings from Pinus radiata under conditions of adventitious root formation. Treatments with bioactive gibberellins inhibited rooting while at the same time inducing both the differentiation of a continuous ring of cambium and xylem formation. Treatments with inhibitors of gibberellin biosynthesis did not affect the rooting response. The results demonstrate that xylem parenchyma and procambial cells at the xylem poles of rooting-competent hypocotyl cuttings after excision and under conditions of adventitious root induction become adventitious root meristems or xylem, depending on the directional auxin flow. Gibberellin may interact with this pathway, inducing xylem differentiation and inhibiting rooting. We conclude that modifications of auxin flow at the rooting sites, and the priming of cambial cells to differentiate into xylem during tree ageing, may be associated with the maturation-related decline of adventitious root formation.

scholarly journals Saline Stress Alters the Temporal Patterns of Xylem Differentiation and Alternative Oxidase Expression in Developing Soybean Roots

1998 ◽  
Vol 117 (2) ◽  
pp. 695-701 ◽  
Author(s):  
Mirna Hilal ◽  
Ana M. Zenoff ◽  
Graciela Ponessa ◽  
Hortensia Moreno ◽  
Eddy M. Massa
Keyword(s):  
Alternative Oxidase ◽  
Temporal Patterns ◽  
Saline Stress ◽  
Xylem Differentiation ◽  
Soybean Roots

scholarly journals Analysis of xylem formation in pine by cDNA sequencing

1998 ◽  
Vol 95 (16) ◽  
pp. 9693-9698 ◽  
Author(s):  
Isabel Allona ◽  
Michelle Quinn ◽  
Elizabeth Shoop ◽  
Kristi Swope ◽  
Sheila St. Cyr ◽  
...  
Keyword(s):  
Cell Wall ◽  
Loblolly Pine ◽  
Secondary Xylem ◽  
Expression Patterns ◽  
Wood Formation ◽  
Xylem Differentiation ◽  
Cell Wall Proteins ◽  
Powerful Means ◽  
Xylem Formation ◽  
Enzymes Of Carbohydrate Metabolism

Secondary xylem (wood) formation is likely to involve some genes expressed rarely or not at all in herbaceous plants. Moreover, environmental and developmental stimuli influence secondary xylem differentiation, producing morphological and chemical changes in wood. To increase our understanding of xylem formation, and to provide material for comparative analysis of gymnosperm and angiosperm sequences, ESTs were obtained from immature xylem of loblolly pine (Pinus taeda L.). A total of 1,097 single-pass sequences were obtained from 5′ ends of cDNAs made from gravistimulated tissue from bent trees. Cluster analysis detected 107 groups of similar sequences, ranging in size from 2 to 20 sequences. A total of 361 sequences fell into these groups, whereas 736 sequences were unique. About 55% of the pine EST sequences show similarity to previously described sequences in public databases. About 10% of the recognized genes encode factors involved in cell wall formation. Sequences similar to cell wall proteins, most known lignin biosynthetic enzymes, and several enzymes of carbohydrate metabolism were found. A number of putative regulatory proteins also are represented. Expression patterns of several of these genes were studied in various tissues and organs of pine. Sequencing novel genes expressed during xylem formation will provide a powerful means of identifying mechanisms controlling this important differentiation pathway.

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