אסיף מאגר המחקר החקלאי

Inhibition of the gravitropic response of snapdragon spikes by the calcium-channel blocker lanthanum chloride

Year:

1998

Source of publication :

Authors :

Volume :

118

Co-Authors:

Friedman, H., Dept. Postharvest Sci. Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Meir, S., Dept. Postharvest Sci. Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Rosenberger, I., Dept. Postharvest Sci. Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Halevy, A.H., Kennedy-Leigh Ctr. for Hort. Res., Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Kaufman, P.B., Department of Biology, University of Michigan, Ann Arbor, MI 48109-1048, United States
Philosoph-Hadas, S., Dept. Postharvest Sci. Fresh Produce, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel

Facilitators :

Link :

Abstract:

The putative Ca2+-channel blocker LaCl3 prevented the gravitropic bending of cut snapdragon (Antirrhinum majus L.) spikes (S. Philosoph-Hadas, S. Meir, I. Rosenberger, A.H. Halevy [1996] Plant Physiol 110: 301-310) and inhibited stem curvature to a greater extent than vertical and horizontal stem elongation at the bending zone. This might indicate that LaCl3, which modulates cytosolic Ca2+, does not influence general stem-growth processes but may specifically affect other gravity-associated processes occurring at the stem-bending zone. Two such specific gravity-dependent events were found to occur in the bending zone of snapdragon spikes: sedimentation of starch-containing chloroplasts at the bottom of stem cortex cells, as seen in cross-sections, and establishment of an ethylene gradient across the stem. Our results show that the lateral sedimentation of chloroplasts associated with gravity sensing was prevented in cross-sections taken from the bending zone of LaCl3treated and subsequently gravistimulatcd spikes and that LaCl3 completely prevented the gravity-induced, asymmetric ethylene production established across the stem-bending zone. These data indicate that LaCl3 inhibits stem curvature of snapdragon spikes by preventing several gravity-dependent processes. Therefore, we propose that the gravitropic response of shoots could be mediated through a Ca2+-dependent pathway involving modulation of cytosolic Ca2+ at various stages.

Note:

Related Files :

Related Content

More details

You may also be interested in