Stem Protective Tissue in Erythroxylum Tortuosum (Erythroxylaceae), A Fire Tolerant Species from Cerrado

IAWA Journal ◽  
2008 ◽  
Vol 29 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Alexandre Antonio Alonso ◽  
Silvia Rodrigues Machado

The origin and structure are described of the secondary protective tissue in the stem of Erythorxylum tortuosum Mart., a fire tolerant shrubby species common in Brazilian cerrado. The highly tortuous stems are covered with thick bark which is more developed at the base of the stem. After fire in the cerrado, rhytidome fragments of the burned stem flake off, revealing newly formed cork. The first periderm appears near of the terminal buds and is iniated by periclinal divisions in subepidermal cells giving rise to radial rows of cells. The first phellogen is discernible only after the differentiation of the several radial rows of cork cells. Other phellogens have their origin in successively deeper layers of the cortex. The sucessive periderms are discontinuous around the circumference. The collapsed cells with phenolic substances and the accumulated dead cells cause the formation of discontinuous blackish lines, which delimit the sucessive periderms in the rhytidome. The rhytidome contains large quantities of sclereids developed from cell wall thickening of cortex cells. The occurrence of periderm in the young parts of the stem and of rhytidome in the older parts represents pyrophytic characteristics and may explain, in part, the fire tolerance of this species.

2020 ◽  
Vol 35 ◽  
pp. 101125 ◽  
Author(s):  
Safia Zeroual ◽  
Salah Eddine El Bakkal ◽  
Mounir Mansori ◽  
Sabine Lhernould ◽  
Céline Faugeron-Girard ◽  
...  

2019 ◽  
Vol 24 (9) ◽  
pp. 853-866 ◽  
Author(s):  
Ian W. McCahill ◽  
Samuel P. Hazen
Keyword(s):  

2020 ◽  
Vol 11 ◽  
Author(s):  
Samaneh Sadat Maleki ◽  
Kourosh Mohammadi ◽  
Ali Movahedi ◽  
Fan Wu ◽  
Kong Shu Ji

2007 ◽  
Vol 55 (7) ◽  
pp. 749 ◽  
Author(s):  
Alexandre Antonio Alonso ◽  
Silvia Rodrigues Machado

Brazilian cerrado, a neotropical savanna, is characterised by a strongly seasonal climate with distinctive wet and dry seasons, and deep and well drained soils that are acidic and with high aluminium content. Recurrent fires in the dry season place additional stress on the survival of plants, which exhibit an array of strategies of survival. The purpose of this work was to study the underground system of Erythroxylum nanum A.St-Hil. and E. campestre A.St-Hil., two sub-shrubby species, and E. tortuosum Mart., a shrubby species, verifying the possible relationship between the morphology of the underground organs and the resprouting ability of these plants. Anatomical analyses followed the usual techniques of plant anatomy. The cotyledons of the three species were green, foliaceous and photosynthesising. The two sub-shrubby species (Erythroxylum nanum and E. campestre) showed slow development of the aerial shoot system and extensive growth of the primary root in the initial stage of development. E. tortuosum presented the most pronounced development of the aerial system and a poorly developed primary root compared with the sub-shrubby species. The sub-shrubby species occurred in clumps and had underground systems interlinked, consisting of a deep axial primary root system besides soboles in E. nanum and xylopodium in E. campestre. Plants of the E. tortuosum were isolated, highly branched and their underground system consisted of a superficial primary root system. Abundance of reserves and the bud-forming potential of the soboles, xylopodium and roots resulted in production of vigorous branches that are highly valuable in the regeneration of the aerial biomass following fire or seasonal dry in cerrado.


2020 ◽  
Vol 183 (4) ◽  
pp. 1600-1611 ◽  
Author(s):  
Daisuke Sugiura ◽  
Ichiro Terashima ◽  
John R. Evans

1978 ◽  
Vol 56 (23) ◽  
pp. 2990-2999 ◽  
Author(s):  
G. Faulkner ◽  
Warwick C. Kimmins

Tissue in Phaseolus vulgaris L. cv. Pinto bean bordering local lesions induced by tobacco mosaic virus showed cell wall deposition associated with paramural body formation in a narrow ring of viable cells extending one to three cell diameters around the lesions. Deposition, which led to secondary cell wall thickening, was greatest 3–4 days after inoculation, the time when the lesion stopped expanding. Secondary cell wall thickening, of similar appearance but less pronounced, was seen in tissue bordering local lesions which continued to expand; no significant secondary cell wall thickening was observed in leaves with a nonlocalized infection. Cells bordering mechanical lesions differed markedly in fine structure from cells bordering virus and chemical lesions. It is suggested that the deposition of extra cell wall material in the wall regions of cells bordering fully expanded local lesions is associated with virus localization.


2020 ◽  
Vol 40 (7) ◽  
pp. 943-955
Author(s):  
Eva Darenova ◽  
Petr Horáček ◽  
Jan Krejza ◽  
Radek Pokorný ◽  
Marian Pavelka

Abstract Stem respiration is an important component of an ecosystem’s carbon budget. Beside environmental factors, it depends highly on tree energy demands for stem growth. Determination of the relationship between stem growth and stem respiration would help to reveal the response of stem respiration to changing climate, which is expected to substantially affect tree growth. Common measurement of stem radial increment does not record all aspects of stem growth processes, especially those connected with cell wall thickening; therefore, the relationship between stem respiration and stem radial increment may vary depending on the wood cell growth differentiation phase. This study presents results from measurements of stem respiration and increment carried out for seven growing seasons in a young Norway spruce forest. Moreover, rates of carbon allocation to stems were modeled for these years. Stem respiration was divided into maintenance (Rm) and growth respiration (Rg) based upon the mature tissue method. There was a close relationship between Rg and daily stem radial increment (dSRI), and this relationship differed before and after dSRI seasonal maximum, which was around 19 June. Before this date, Rg increased exponentially with dSRI, while after this date logarithmically. This is a result of later maxima of Rg and its slower decrease when compared with dSRI, which is connected with energy demands for cell wall thickening. Rg reached a maxima at the end of June or in July. The maximum of carbon allocation to stem peaked in late summer, when Rg mostly tended to decrease. The overall contribution of Rg to stem CO2 efflux amounted to 46.9% for the growing period from May to September and 38.2% for the year as a whole. This study shows that further deeper analysis of in situ stem growth and stem respiration dynamics is greatly needed, especially with a focus on wood formation on a cell level.


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