Casparian Strips in the Leaf Intrastelar Canals of Isoetes duriei Bory, a Mediterranean Terrestrial Species

Romeo, D. J.; Troìa, Angelo; Burgarella, Concetta; Bellini, E.

doi:10.1006/anbo.2000.1273

Cited by 10 publications

(10 citation statements)

References 10 publications

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“…At the present time, the genus includes some terrestrial species, such as Isoetes histrix and Isoetes duriei, whose aerial leaves have functional stomata but also exhibit some features of aquatic leaves, such as wide aerenchyma chambers and endodermis-like sheaths around intrastelar canals of vascular bundles. These findings have led Romeo et al (2000) to suggest that the peculiar leaf structures could be relic traits due to the origin of terrestrial Isoetes from secondarily aquatic ancestors derived, in turn, from the originally terrestrial ones. Therefore, according to this hypothesis, already assumed also by Keeley (1983), the present terrestrial species of Isoetes should be regarded as "secondarily terrestrial plants"…”

Section: Emerged Aam Plantsmentioning

confidence: 95%

The Underwater Life of Secondarily Aquatic Plants: Some Problems and Solutions

Rascio¹

2002

Critical Reviews in Plant Sciences

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The freshwater secondarily aquatic plants, most of which are higher plants, are those returned to the water environment after spending a period of time living on land. The readaptation to living underwater has made it necessary for these plants to put in place morphological and functional strategies to cope with some major problems due to features of the aquatic environment, but also deriving from the specialized organization of their "terrestrial" bodies. The poor O 2 availability underwater accounted for the evolution of wide aerenchyma tissues throughout the plant organs to improve the photosynthetic O 2 flux from the shoot to the roots buried in anoxic sediments and to the neighboring rhizosphere. This favors sediment oxygenation, sustains the aerobic metabolism of roots, and improves the availability and uptake of mineral nutrients, whose delivery to the entire plants, without a transpirational flux, is ensured by an acropetal mass transport depending on root pressure, guttation from hydathodes and channeling by apoplast closure around the vascular tissues. A great expansion of leaf surfaces and an enhanced surface:volume ratio of chloroplast-rich photosynthetic cells help to contact the water medium and to increase the cell/environment exchanges to gain inorganic carbon. Furthermore, different physiological mechanisms operate to cope with the scarce availability of CO 2 and the prevalence of HCO 3 -as inorganic carbon form in water. Some of them, like cell wall acidification through H + extrusion by a light-dependent APTase or activation of an apoplastic carbonic anhydrase, operate outside the cells, leading to a conversion of HCO 3 -to CO 2 , which then diffuses into the cells. Others, on the contrary, act inside the cells to load the active site of Rubisco with CO 2 , thus favoring photosynthesis and lowering photorespiration. Aquatic macrophytes with isoetid life form, moreover, can obtain most ot the fixed CO 2 from sediments. In submerged species, in additin to the C 3 cycle, the C 4 and CAM-like photosynthetic metabolisms can also operate, and are modulated by the environmental inorganic carbon availability and the plant photosynthetic demand. Interestingly, in the aquatic plants the C 4 pathway, which can be concomitant with the C 3 one, does not depend on the Kranz anatomy of leaves, but relies on the intracellular compartmentation of carboxylative and decarboxylative enzymes. The CAM-like pathway, defined AAM, which also coexists with the C 3 , allows the submerged plants to fix CO 2 in the dark, thus exploiting the higher CO 2 availability in the water medium during the night, and extending to 24 h the period of inorganic carbon assimilation. In almost all the aquatic macrophytes the AAM is only expressed in the submersion state, whereas it is quickly inactivated in emerging leaves in a cell by cell way.

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Section: Emerged Aam Plantsmentioning

confidence: 95%

The Underwater Life of Secondarily Aquatic Plants: Some Problems and Solutions

Rascio¹

2002

Critical Reviews in Plant Sciences

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“…1 A-D). Romeo et al (2000) ilustraron en I. durieui, mediante fluorescencia inducida por colorantes, la endodermis presente en esta zona, que se encuentra en su etapa primaria y presenta bandas de Caspary. Aquí se observó solamente en un ejemplar de I. velata subsp.…”

Section: Resultados Y Discusiónunclassified

“…1E). Las bandas de Caspary están formadas por suberina (Romeo et al, 2000) o por suberina y lignina, ésta detectada aquí mediante el TBO.…”

Section: Resultados Y Discusiónunclassified

“…La presencia de esa capa se conoce desde hace más de un siglo y ha sido mencionada por Janczeski (1882), en Scott & Hill (1900), para I. durieui; por Scott & Hill (1900), para I. histrix; por Sadebeck (1902) para I. lacustris y por West & Takeda (1915), para I. japonica. Más recientemente, Romeo et al (2000), la ilustran en I. durieui y la ponen en evidencia mediante fluorescencia inducida por colorantes, indicando que se desarrolla en el canal intrastelar central y que presenta bandas de Caspary formadas por suberina. West & Takeda (1915) son los únicos que mencionan, para I. japonica, células con paredes ligeramente cutinizadas bordeando las cámaras aeríferas, sin hacer ninguna interpretación de este fenómeno.…”

Section: Introductionunclassified

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Endodermis foliares en el género Isoetes L. (Isoetaceae).

Rolleri¹,

Prada²

2004

abm

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RESUMEN. Endodermis foliares en el género Isoetes L. (Isoetaceae). La presencia y naturaleza de la endodermis en microfilos de 18 taxones de Isoetes se puso de manifiesto con técnicas microquímicas de coloración con TBO y mediante fluorescencia intrínseca (autofluorescencia). Las especies estudiadas son: I. adspersa, I. andina, I. boliviensis, I. boryana, I.brochonii, I. durieui, I. echinospora, I.engelmanii, I. histrix, I. lacustris, I. lechleri, I. longissima, I. malinverniana, I. melanopoda, I. setacea, I. storkii, I. velata subsp. velata, I. velata subsp. asturicense. Desde el punto de vista morfológico se reconocen tres tipos de endodermis, que coexisten en la misma hoja. Una endodermis primaria con bandas de Caspary, que se desarrolla inicialmente rodeando los canales intrastelares, pero que evolucionaría hacia endodermis secundaria (con engrosamientos «en U»), ya que éste es el tipo que se encuentra en torno de los canales intrastelares en microfilos de todas las especies estudiadas. También se forma una endodermis secundaria (con engrosamientos «en U»), parcial o completa, rodeando las cámaras aeríferas, en todas las especies estudiadas. Las especies que crecen a mayor altura sobre el nivel del mar pueden desarrollar en esta zona una endodermis terciaria (con engrosamientos «en O»). La endodermis de las cámaras aeríferas está menos desarrollada o desaparece en la porción del microfilo que se encuentra hundida en el sustrato, no así la endodermis de los canales intrastelares. La función reguladora del flujo de agua y metabolitos entre el haz vascular y el mesofilo explicaría tanto la presencia como la especialización de estas capas en microfilos sujetos a estrés hídrico.Palabras clave. Isoetes, microfilos, anatomía, endodermis, estrés hídricoABSTRACT. Foliar endodermis in genus Isoetes L. (Isoetaceae). Microchemical analysis with TBO, and intrinsic fluorescence (autofluorescence) were used to detect the presence and occurrence of endodermis in microphylls of 18 taxa of genus Isoetes (I. adspersa, I. andina, I. boliviensis, I. boryana, I.brochonii, I. durieui, I. echinospora, I.engelmanii, I. histrix, I. lacustris, I. lechleri, I. longissima, I. malinverniana, I. melanopoda, I. setacea, I. storkii, I. velata subsp. velata, I. velata subsp. asturicense). From a morphological point of view, three known endodermal types can be found in the microphylls, and they also coexist in the same leaf. Casparian strips are developed in a primary endodermis that surrounds intrastelar canals, which probably progress to a secondary endodermis (with «U thickenings»), since microphylls of all studied species bear secondary, suberized and lignified endodermis in every intrastelar canal. A secondary or even a tertiary lignified endodermis develops in mesophyll cells of the central area of the leaf next to the air chambers; secondary endodermis occurs in all studied species, and tertiary endodermis was found only in species that live in bogs, moors or seasonal swamps, at the higher altitudes in the Southamerican Andes. Endodermis of the air chambers become thinner or disappears in the buried part of the microphylls, while the endodermis of intrastelar canals does not change. Comments are made on the adaptive significance of specialized endodermal layer in aquatic, amphibious and terrestrial species. The participation of the endodermis in the regulation of the loss of water and metabolites from the vascular system to the mesophyll could be an explanation of the presence of these layers.Key words. Isoetes, microphylls, anatomy, endodermis, hydric stress

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“…Troia et al (1999) estudiaron la anatomía foliar comparada de dos especies, I. durieui Bory e I. histrix Bory, pero la ú nica diferencia que destacaron fue el mayor tamañ o de las células oclusivas de los estomas de la primera. Romeo et al (2000) estudiaron la estructura de los canales intrastelares y pusieron en evidencia, mediante fluorescencia inducida por colorantes, la endodermis con bandas de Caspary presente en los mismos. Musselman y Roux (2002) ilustraron por primera vez, con microscopía electrónica de barrido, las ornamentaciones cuticulares con forma de verrugas, en I. toximontana L. J. Musselman & J. P. Roux.…”

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