Daily Changes in Stem Thickness and Related Gas Exchange Patterns for the Hemiepiphytic CactusHylocereus undatus

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The University of Chicago Press is collaborating with JSTOR to digitize, preserve and extend access to International Journal of Plant Sciences.Pairs of linearly variable differential transducers, with a sensitivity of 1 mm, were used to compare daily changes in stem thickness with transpiration and net CO 2 uptake for the hemiepiphyte Hylocereus undatus and to examine the possible effects of hormonal signals from its roots. Two daily patterns of transpiration were observed for well-watered H. undatus: solely nocturnal stomatal opening, which can occur for obligate crassulacean acid metabolism (CAM), and CAM with substantial daytime stomatal opening associated with C 3 photosynthesis. Each caused different daily patterns of stem thickness, which could be affected by changes in relative humidity within 1 min. Removing possible root signals by severing distal stem segments or by rapidly drying the root system increased the maximal transpiration rate over 4 d, indicating that root hormonal signals influence stomatal opening, even under well-watered conditions. Rewatering plants that had their root systems air dried for 4 d resulted in rapid water uptake, reduced the magnitude of daily thickness changes, and led to the recovery of original stem thickness in ca. 4 d. Stem injections of abscisic acid equivalent to a 1 mM average tissue concentration halved transpiration and eliminated daily net CO 2 uptake. Measurements of stem thickness can help interpret patterns of water movement and the influence of hormonal signals on gas exchange for this vinelike cactus.

Correlation of drought traits and the predictability of osmotic potential at full leaf turgor in vegetation from New Zealand

“…). Conversely, rapid stomatal closure can prevent water loss and embolism and maintain high water potentials (North & Nobel ; Benzing ; Graham & Nobel ; Martin‐StPaul et al . ).…”

Parenchyma–Chlorenchyma Water Movement during Drought for the Hemiepiphytic Cactus Hylocereus undatus

“…Hylocereus undatus, the species considered in the present study, is cultivated in 20 countries for its fruit and is also used as an ornamental (Mizrahi and Nerd, 1999;Nobel and De la Barrera, 2004). It is a slender hemiepiphytic cactus native to dry tropical forests from Mexico to northern South America (Ortíz, 1999;Nobel and De la Barrera, 2004) and exhibits CAM, with stomatal opening predominantly at night (Ortíz et al, 1996;Raveh et al, 1998), leading to daily oscillations in stem thickness (Graham and Nobel, 2005). Its sequential stem segments can develop adventitious roots, so each rooted stem segment can act as an individual unit for water uptake.…”

Sensitivity and Regulation of Diel Photosynthesis in Red-Fleshed Pitaya (Hylocereus polyrhizus) Micropropagules under Mannitol-Induced Water Stress/Rehydration Cycle In Vitro

“…However, long-term WS-induced stomatal closure and impaired photosynthesis decreased diel INCU by 78% [14,17,21,30]. Similarly, Pn reduced by 48% in H. undatus micropropagules after a 14-day drought [31] that was reversed by 7-day irrigation [18,29].…”

“…Well-watered crassulacean acid metabolism (CAM) plants, such as Hylocereus spp., Kalanchoe pinnata, Opuntia basilaris, and Agave deserti [9][10][11][12], develop robust succulent shoots with abundant mucilage [13,14], organic acids, and C-assimilation. Although CAM plants can grow in arid/semi-arid regions [15,16], continuous water stress (WS) disrupted C-uptake, as observed in H. undatus and K. daigremontiana [17][18][19], probably due to the oxidative damage of chlorophyll and photosynthetic apparatus [5,20,21], also reported in C 3 and C 4 plants [22].…”