Succulence and CAM relationships in Aeonium genus

Abstract

Abstract. The CAM has been tested in six species of the Aeonium genus by studying the diurnal fluctuation of organic acids, pH and night fixation of CO 2 . The existence of a rnesophyll structure able to support this metabolism has been shown as well as a congruent periodicity in the pool of cell starch.We have calculated the S, ES and Sm indices in the six species. A series of regression equations of different grades and types were calculated and shown to have correlation coefficients statistically significant. This allows us to confirm the suitability of the Sm index as a rapid test to establish the CAM as postulated by former authors.Resumen. Se ha comprobado el CAM en seis especies del g6nero Aeonium, mediante el estudio de las fluctuaciones diurnas del acervo de ~cidos org~nicos, de las oscilaciones peri6dicas de pH y de la captura nocturna de CO2, al mismo tiempo que se ha verificado en elias le existencia de una estructura del mes6filo capaz de soportar este metabolismo y una periodicidad congruente en el acervo de almid6n celular.Se han calculado asirnismo los indices S, ES y Sm de especflnenes de las seis especies y se ha podido establecer una serie de ecuaciones de regresi6n de distinto tipo y grado, a unos niveles de signfficaci6n, que permiten postular, en el citado material, la idoneidad del indice Sm como prueba r~pida del metabolismo ~eido de las crasul~ceas, confirmando de este modo las teorias de los primeros autores.

Diel patterns of CO2 exchange for epiphytic cacti differing in succulence

“…Certain investigators (e.g., Kluge andTing 1978, Jimenez et al 1983) favor mass of water per unit of ehlorophyll for representing degree of sueeulenee and hence degree of CAM behavior. This quantity averages 0.59 kg g~' for 9 non-CAM species and 4.7 kg g ' for 7 CAM species (Jimenez et al 1983). Consistent with this, the water mass per unit mass of chlorophyll ranged from about 1 kg g"' for the epiphytic cactus with C^-hke behavior up to 3 kg g"' for the species with full CAMlike behavior.…”

“…IE). Aeonium plaeed in sealed flasks, the nocturnal deerease in CQ2 concentration becomes greater as the water mass per unit area increases 6-fold from 0.3 kg m"^ (Jimenez et al 1983). Similarly, as the water mass per unit area increases 8-fold from 0.2 kg m -for leaves of 13 species of Senecio, the earbon isotope ratio shifts from that characteristic of C, plants (-28%o) to a value approximately halfway between that of C, and full-CAM plants (-20%,,, Fioretto and Alfani 1988).…”

“…ucculence has been described using characteristics ganging from the size of chlorenchyma cells to organ volume and hence water storage per unit surface area (Kluge and Ting 1978, Gibson 1982, Gibson and Nobel 1986. In particular, succulence has been quantitatively expressed on the basis of mass of water per unit mass of chlorophyll, mass of water per unit surface area, tissue fnass or fresh weight per unit surface area and organ thickness (Kluge and Ting 1978, Teeri et al 1981, Jimenez et al 1983, Fioretto and Alfani 1988. An objective of the present study was to determine the daily net CO, uptake patterns of 6 species of epiphytic cacti varying in these measures of succulence.…”

Elastic and collapsible: current understanding of cell walls in succulent plants

“… Melo-de-Pinna et al , 2014 ; Ogura et al , 2018 ), Crassulaceae (e.g. Jiménez et al , 1983 ; Sandoval-Zapotitla et al , 2019 ), Bromeliaceae (e.g. Gomes-da-Silva et al , 2012 ; Reinert et al , 2013 ), Gesneriaceae (e.g.…”