Abstract
Single-celled spores of the fern Ceratopteris richardii undergo gravity-directed cell polarity development that is driven by polar calcium currents. Here we present results that establish a role for nitric oxide (NO)/cGMP signaling in transducing the stimulus of gravity to directed polarization of the spores. Application of specific NO donors and scavengers inhibited the calcium-dependent gravity response in a dose-dependent manner. the effects of NO donor exposure were antagonized by application of NO scavenger compounds. Similarly, the guanylate cyclase inhibitors 6-anilino-5,8- quinolinedione and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin, and the phosphodiesterase inhibitor Viagra, which modulate NO-dependent cGMP levels in the cells, disrupted gravity-directed cell polarity in a dose-dependent manner. Viagra effects were antagonized by application of NO scavengers, consistent with the postulate that NO and cGMP are linked in the signaling pathway. to identify other components of the signaling system we analyzed gene expression changes induced by Viagra treatment using microarrays and quantitative real-time reverse transcription-polymerase chain reaction. Preliminary microarray analysis revealed several genes whose expression was significantly altered by Viagra treatment. Three of these genes had strong sequence similarity to key signal transduction or stress response genes and quantitative real-time reverse transcription-polymerase chain reaction was used to more rigorously quantify the effects of Viagra on their expression in spores and to test how closely these effects could be mimicked by treatment with dibutyryl cGMP. Taken together our results implicate NO and cGMP as downstream effectors that help link the gravity stimulus to polarized growth in C. richardii spores. © 2007 American Society of Plant Biologists.
Recommended Citation
M. L. Salmi et al., "Nitric Oxide and CGMP Signaling in Calcium-Dependent Development of Cell Polarity in Ceratopteris Richardii," Plant Physiology, vol. 144, no. 1, pp. 94 - 104, Oxford University Press; American Society of Plant Biologists, Jan 2007.
The definitive version is available at https://doi.org/10.1104/pp.107.096131
Department(s)
Biological Sciences
Publication Status
Open Access
International Standard Serial Number (ISSN)
1532-2548; 0032-0889
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Oxford University Press; American Society of Plant Biologists, All rights reserved.
Publication Date
01 Jan 2007
