scholarly journals Imperforate tracheary elements and vessels alleviate xylem tension under severe dehydration: insights from water release curves for excised twigs of three tree species

2020 ◽  
Vol 107 (8) ◽  
pp. 1122-1135 ◽  
Author(s):  
Kenichi Yazaki ◽  
Delphis F. Levia ◽  
Akiko Takenouchi ◽  
Makoto Watanabe ◽  
Daisuke Kabeya ◽  
...  
Keyword(s):  
Tree Species ◽  
Tracheary Elements ◽  
Severe Dehydration ◽  
Water Release

Hydraulic traits of Neotropical canopy liana and tree species across a broad range of wood density: implications for predicting drought mortality with models

2020 ◽  
Author(s):  
Mark E De Guzman ◽  
Aleyda Acosta-Rangel ◽  
Klaus Winter ◽  
Frederick C Meinzer ◽  
Damien Bonal ◽  
...  
Keyword(s):  
Water Potential ◽  
Water Transport ◽  
Wood Density ◽  
Drought Resistance ◽  
Tree Species ◽  
Forest Site ◽  
Xylem Cavitation ◽  
Water Release ◽  
Trade Offs ◽  
Maximum Water

Abstract Wood density (WD) is often used as a proxy for hydraulic traits such as vulnerability to drought-induced xylem cavitation and maximum water transport capacity, with dense-wooded species generally being more resistant to drought-induced xylem cavitation, having lower rates of maximum water transport and lower sapwood capacitance than light-wooded species. However, relationships between WD and the hydraulic traits that they aim to predict have not been well established in tropical forests, where modeling is necessary to predict drought responses for a high diversity of unmeasured species. We evaluated WD and relationships with stem xylem vulnerability by measuring cavitation curves, sapwood water release curves and minimum seasonal water potential (Ψmin) on upper canopy branches of six tree species and three liana species from a single wet tropical forest site in Panama. The objective was to better understand coordination and trade-offs among hydraulic traits and the potential utility of these relationships for modeling purposes. We found that parameters from sapwood water release curves such as capacitance, saturated water content and sapwood turgor loss point (Ψtlp,x) were related to WD, whereas stem vulnerability curve parameters were not. However, the water potential corresponding to 50% loss of hydraulic conductivity (P50) was related to Ψtlp,x and sapwood osmotic potential at full turgor (πo,x). Furthermore, species with lower Ψmin showed lower P50, Ψtlp,x and πo,x suggesting greater drought resistance. Our results indicate that WD is a good easy-to-measure proxy for some traits related to drought resistance, but not others. The ability of hydraulic traits such as P50 and Ψtlp,x to predict mortality must be carefully examined if WD values are to be used to predict drought responses in species without detailed physiological measurements.

Anatomy and ultrastructure of haustoria in selected West Australian parasitic angiosperms

1990 ◽  
Vol 48 (3) ◽  
pp. 690-691
Author(s):  
John Kuo ◽  
John S. Pate
Keyword(s):  
Parasitic Plants ◽  
The Other ◽  
Nutrient Transfer ◽  
Direct Solution ◽  
Tracheary Elements ◽  
Solute Transfer ◽  
Glycol Methacrylate ◽  
Australian Species ◽  
Anatomy And Ultrastructure ◽  
Solution Transfer

Our understanding of nutrient transfer between host and flowering parasitic plants is usually based mainly on physiological concepts, with little information on haustorial structure related to function. The aim of this paper is to study the haustorial interface and possible pathways of water and solute transfer between a number of host and parasites.Haustorial tissues were fixed in glutaraldehyde and embedded in glycol methacrylate (LM), or fixed in glutaraldehyde then OsO4 and embedded in Spurr’s resin (TEM).Our study shows that lumen to lumen continuity occurs between tracheary elements of a host and four S.W. Australian species of aerial mistletoes (Fig. 1), and some root hemiparasites (Exocarpos spp. and Anthobolus foveolatus) (Fig. 2). On the other hand, haustorial interfaces of the root hemiparasites Olax phyllanthi and Santalum (2 species) are comprised mainly of parenchyma, as opposed to terminating tracheads or vessels, implying that direct solution transfer between partners via vessels or tracheary elements may be limited (Fig. 3).

Structural aspects of tracheary element differentiation in suspension cultures of Zinnia elegans

1989 ◽  
Vol 47 ◽  
pp. 768-769
Author(s):  
C. H. Haigler ◽  
A. W. Roberts
Keyword(s):  
Tracheary Element ◽  
Vesicle Fusion ◽  
Zinnia Elegans ◽  
Cellulose Synthesis ◽  
Tracheary Elements ◽  
Animal Cells ◽  
Mesophyll Cells ◽  
Fixation Techniques ◽  
Localized Patterns ◽  
Structural Aspects

Tracheary elements, the water-conducting cells in plants, are characterized by their reinforced walls that became thickened in localized patterns during differentiation (Fig. 1). The synthesis of this localized wall involves abundant secretion of Golgi vesicles that export preformed matrix polysaccharides and putative proteins involved in cellulose synthesis. Since the cells are not growing, some kind of endocytotic process must also occur. Many researchers have commented on where exocytosis occurs in relation to the thickenings (for example, see), but they based their interpretations on chemical fixation techniques that are not likely to provide reliable information about rapid processes such as vesicle fusion. We have used rapid freezing to more accurately assess patterns of vesicle fusion in tracheary elements. We have also determined the localization of calcium, which is known to regulate vesicle fusion in plant and animal cells.Mesophyll cells were obtained from immature first leaves of Zinnia elegans var. Envy (Park Seed Co., Greenwood, S.C.) and cultured as described previously with the following exceptions: (a) concentration of benzylaminopurine in the culture medium was reduced to 0.2 mg/l and myoinositol was eliminated; and (b) 1.75ml cultures were incubated in 22 x 90mm shell vials with 112rpm rotary shaking. Cells that were actively involved in differentiation were harvested and frozen in solidifying Freon as described previously. Fractures occurred preferentially at the cell/planchet interface, which allowed us to find some excellently-preserved cells in the replicas. Other differentiating cells were incubated for 20-30 min in 10(μM CTC (Sigma), an antibiotic that fluoresces in the presence of membrane-sequestered calcium. They were observed in an Olympus BH-2 microscope equipped for epi-fluorescence (violet filter package and additional Zeiss KP560 barrier filter to block chlorophyll autofluorescence).

Purification of plasma membranes from leaves of conifer and deciduous tree species by phase partitioning and free-flow electrophoresis

1995 ◽  
Vol 95 (3) ◽  
pp. 399-408 ◽  
Author(s):  
Elena Toll ◽  
Federico J. Castillo ◽  
Pierre Crespi ◽  
Michele Crevecoeur ◽  
Hubert Greppin
Keyword(s):  
Tree Species ◽  
Plasma Membranes ◽  
Free Flow ◽  
Deciduous Tree ◽  
Phase Partitioning

Biscogniauxia (Hypoxylon) Canker or Dieback in Trees

EDIS ◽  
2017 ◽  
Vol 2017 (6) ◽  
Author(s):  
Claudia Paez ◽  
Jason A. Smith
Keyword(s):  
Water Stress ◽  
Tree Species ◽  
Soil Compaction ◽  
Urban Areas ◽  
Root Disease ◽  
Poor Health ◽  
Green Spaces ◽  
Opportunistic Pathogens ◽  
Wide Range ◽  
Quercus Spp

Biscogniauxia canker or dieback (formerly called Hypoxylon canker or dieback) is a common contributor to poor health and decay in a wide range of tree species (Balbalian & Henn 2014). This disease is caused by several species of fungi in the genus Biscogniauxia (formerly Hypoxylon). B. atropunctata or B. mediterranea are usually the species found on Quercus spp. and other hosts in Florida, affecting trees growing in many different habitats, such as forests, parks, green spaces and urban areas (McBride & Appel, 2009).  Typically, species of Biscogniauxia are opportunistic pathogens that do not affect healthy and vigorous trees; some species are more virulent than others. However, once they infect trees under stress (water stress, root disease, soil compaction, construction damage etc.) they can quickly colonize the host. Once a tree is infected and fruiting structures of the fungus are evident, the tree is not likely to survive especially if the infection is in the tree's trunk (Anderson et al., 1995).

Climate resilience through natural regeneration in degraded natural forests of south-eastern hilly region of Bangladesh

2019 ◽  
Vol 48 (3) ◽  
pp. 417-425
Author(s):  
Md Khayrul Alam Bhuiyan ◽  
Md Akhter Hossain ◽  
Abdul Kadir Ibne Kamal ◽  
Mohammed Kamal Hossain ◽  
Mohammed Jashimuddin ◽  
...  
Keyword(s):  
Tree Species ◽  
Natural Regeneration ◽  
Diversity Indices ◽  
Acacia Auriculiformis ◽  
Quantitative Structure ◽  
Natural Forests ◽  
Climate Resilience ◽  
Hilly Region ◽  
Major Cluster ◽  
Ecological Dominance

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.

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