Journal
JOURNAL OF EXPERIMENTAL BOTANY
Volume 56, Issue 412, Pages 685-694Publisher
OXFORD UNIV PRESS
DOI: 10.1093/jxb/eri051
Keywords
ascorbate; dehydroascorbate; glucose-6-phosphate dehydrogenase; L-galactono-gamma-lactone; onion roots; peroxidase; root elongation
Categories
Ask authors/readers for more resources
Onions (Allium cepa L.) treated with external ascorbic acid or with the immedilate precursor of its synthesis L-galactono-gamma-lactone show a stimulated elongation rate of the roots and an increase in the number of new radicles appearing at the bulb base. Treatment with both molecules resulted in an enhanced accumulation of ascorbate and dehydroascorbate along the root axis, but the distribution of these redox forms was not uniform along the root, as detected in intracellular (symplastic) and extracellular (apoplastic) compartments. Thus, those radicular zones metabolically more active, such as the meristem and the elongation zone, accumulated the highest amount of both redox forms of ascorbate. On the other hand, ascorbate and L-galactono-l-lactone also stimulated cytosolic glucose-6-phosphate dehydrogenase activity and inhibited peroxidase activity as deduced from in vivo and in vitro experiments. Differences were also found when comparing apoplastic and symplastic activities. These results are compatible with the idea of an ascorbate-mediated stimulation of root growth by inhibiting cell wall stiffening and increasing root metabolism.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available