Use este identificador para citar ou linkar para este item: https://locus.ufv.br//handle/123456789/18851
Tipo: Artigo
Título: Leaves, not roots or floral tissue, are the main site of rapid, external pressure-induced ABA biosynthesis in angiosperms
Autor(es): Cardoso, Amanda A.
Zhang, Feng-Ping
Sussmilch, Frances
Nichols, David S.
Brodribb, Timothy J.
McAdam, Scott A.M.
Abstract: Rapid biosynthesis of abscisic acid (ABA) in the leaf, triggered by a decrease in cell volume, is essential for a functional stomatal response. However, it is not known whether rapid biosynthesis of ABA is also triggered in other plant tissues. Through the application of external pressure to flower, root, and leaf tissues, we test whether a reduction in cell volume can trigger rapid increases in ABA levels across the plant body in two species, Solanum lycopersicum and Passiflora tarminiana. Our results show that, in contrast to rapid ABA synthesis in the leaf, flower and root tissue did not show a significant, increase in ABA level in response to a drop in cell volume over a short time frame, suggesting that rapid ABA biosynthesis occurs only in leaf, not in flower or root tissues. A gene encoding the key, rate-limiting carotenoid cleavage enzyme (9-cis-epoxycarotenoid dioxygenase, NCED) in the ABA biosynthetic pathway in S. lycopersicum, NCED1, was upregulated to a lesser degree in flowers and roots compared with leaves in response to applied pressure. In both species, floral tissues contained substantially lower levels of the NCED substrate 9’-cis-neoxanthin than leaves, and this ABA precursor could not be detected in roots. Slow and minimal ABA biosynthesis was detected after 2 h in petals, indicating that floral tissue is capable of synthesizing ABA in response to sustained water deficit. Our results indicate that rapid ABA biosynthesis predominantly occurs in the leaves, and not in other tissues.
Palavras-chave: Abscisic acid
Cell volume
9’-cis-epoxycarotenoid dioxygenase
Flowers
Roots
Stomata
Editor: Journal of Experimental Botany
Tipo de Acesso: Open Access
URI: https://doi.org/10.1093/jxb/erx480
http://www.locus.ufv.br/handle/123456789/18851
Data do documento: 29-Jan-2018
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