Microtubules, MAPs and Xylem Formation

2010 ◽  
pp. 277-306 ◽  
Author(s):  
Edouard Pesquet ◽  
Clive Lloyd
Keyword(s):  
Xylem Formation

scholarly journals Verticillium Infection Triggers VASCULAR-RELATED NAC DOMAIN7–Dependent de Novo Xylem Formation and Enhances Drought Tolerance in Arabidopsis

2012 ◽  
Vol 24 (9) ◽  
pp. 3823-3837 ◽  
Author(s):  
Michael Reusche ◽  
Karin Thole ◽  
Dennis Janz ◽  
Jekaterina Truskina ◽  
Sören Rindfleisch ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
De Novo ◽  
Xylem Formation

scholarly journals Cambial Activity of Moringa peregrina (Forssk.) Fiori in Arid Environments

2021 ◽  
Vol 12 ◽  
Author(s):  
Holger Gärtner ◽  
Emad Farahat
Keyword(s):  
Photosynthetic Activity ◽  
Storage Capacity ◽  
Cambial Activity ◽  
Ring Formation ◽  
Arid Environments ◽  
Dry Tropics ◽  
Xylem Formation ◽  
Moringa Peregrina ◽  
Desert Regions ◽  
Environmental Adaptability

Moringa peregrina (Forssk.) Fiori, one of 13 species of the Moringaceae family widely distributed throughout the dry tropics, has the potential to become one of the most economically important medicinal plants in Egypt. However, despite its tolerance for drought and heat, it is also threatened by increasing temperatures and decreasing precipitation. Although the phenophase of this species is well documented, almost nothing is known about its period of cambial activity in desert regions. Ring formation and the general environmental adaptability of trees are affected by the timing of cambial activation. In our study site, we observe a distinct coupling of the development of new green leaves at the onset of vegetative growth in October and the phase of cambial activity (November–January). The onset of cambial activity seems to be related to a drop in temperature in October and the onset of torrential rains in the region. There might even be a short phase between the end of cambial activity and the onset of bud formation without xylem formation, but with photosynthetic activity. If so, we assume that all assimilates are stored as non-structural carbohydrates (NSC) in the parenchyma of the new ring. This potential gap opens new questions regarding the correlation between NSC storage capacity and the timing of remobilization for subsequent ring formation.

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.

Effect of Ethephon on Mesquite and Huisache Stem Anatomy

Weed Science ◽  
1974 ◽  
Vol 22 (3) ◽  
pp. 280-284 ◽  
Author(s):  
W. E. Robnett ◽  
P. R. Morey
Keyword(s):  
Parenchyma Cell ◽  
Vessel Element ◽  
Inhibitory Effects ◽  
Xylem Parenchyma ◽  
Stem Anatomy ◽  
Acacia Farnesiana ◽  
Secondary Wall Deposition ◽  
Normal Vessel ◽  
Xylem Formation ◽  
Honey Mesquite

Application of the ethylene-releasing agent ethephon (2-chloroethylphosphonic acid) as a lanolin paste to stems of honey mesquite [Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockrell] caused the development of abnormal periderm, cortical, and xylem tissues in a localized portion of the stem within 1 cm of the treatment site. Ethephon inhibited secondary wall deposition in xylem parenchyma cells, whereas normal vessel element differentiation was unaffected. Similar changes in xylem formation occur in ethephon-treated huisache [Acacia farnesiana(L.) Willd.]. Ethephon and 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid] applied separately to honey mesquite and huisache stems have similar inhibitory effects on parenchyma cell differentiation but differ markedly in their effects on vessel element formation.

Eucalyptus gunnii CCR and CAD2 promoters are active in lignifying cells during primary and secondary xylem formation in Arabidopsis thaliana

2006 ◽  
Vol 44 (11-12) ◽  
pp. 674-683 ◽  
Author(s):  
A. Baghdady ◽  
A.-S. Blervacq ◽  
L. Jouanin ◽  
J. Grima-Pettenati ◽  
P. Sivadon ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Secondary Xylem ◽  
Xylem Formation

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.

The effects of artificial soil frost on cambial activity and xylem formation in Norway spruce

Trees ◽  
2011 ◽  
Vol 26 (2) ◽  
pp. 405-419 ◽  
Author(s):  
Tuula Jyske ◽  
Markku Manner ◽  
Harri Mäkinen ◽  
Pekka Nöjd ◽  
Heli Peltola ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Cambial Activity ◽  
Artificial Soil ◽  
Soil Frost ◽  
Xylem Formation
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