Spatiotemporal Patterning of Reactive Oxygen Production and Ca²⁺ Wave Propagation in Fucus Rhizoid Cells

NAD(P)H Oscillates in Pollen Tubes and Is Correlated with Tip Growth

“…We also provide preliminary evidence about ROS production in pollen tubes. In agreement with several others (Pei et al, 2000;Murata et al, 2001;Coelho et al, 2002;Foreman et al, 2003), our studies are consistent with the idea that NAD(P)H is a prime participant. Staining the pollen tubes with CM-H 2 DCFDA reveals that ROS are most concentrated in the region where mitochondria accumulate and also where the NAD(P)H levels are most elevated (Fig.…”

“…6). A subapical, mitochondrial association with ROS production is also seen in tip-growing rhizoids of Fucus (Coelho et al, 2002). Despite these similarities, the Fucus rhizoid in addition shows a region of ROS production at the extreme apex that is not seen in pollen tubes.…”

“…In other systems, notably, root hairs (Foreman et al, 2003), guard cells (Pei et al, 2000), and algal rhizoids (Coelho et al, 2002), interest has focused on a role for NAD(P)H in the generation of reactive oxygen species (ROS). Specifically, the oxidation of NAD(P)H has been associated with the formation of ROS, which are thought to play a signaling role that is central to polarized growth.…”

“…Specifically, the oxidation of NAD(P)H has been associated with the formation of ROS, which are thought to play a signaling role that is central to polarized growth. To determine their status in pollen tubes, we stained the cells with 5-(and-6)-chloromethyl-2#,7#-dichlorohydrofluorescein acetate (CM-H 2 DCFDA), a fluorescent dye that has been used to detect ROS in other plant cells (Pei et al, 2000;Coelho et al, 2002), and then immediately microinjected the same pollen tube (less than 5 min) with the reference dye tetramethylrhodamine dextran (70 kD). Examination of ratio images reveals a region with high ROS production that is located in the subapical region at the base of the clear zone (Fig.…”

The Ectocarpus genome and the independent evolution of multicellularity in brown algae

“…Members of all these classes are found in animal genomes but are absent from the genomes of land plants 21,22 . No IP3R genes have been identified in the sequenced diatom and oomycete genomes, but the presence of an IP3R in Ectocarpus is consistent with the demonstration of 'animal-like' fast calcium waves and inositolphosphate-induced calcium release in embryos of the brown alga Fucus serratus 23,24 .…”