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Osmotic stress‐ and indole‐3‐butyric acid‐induced NO generation are partially distinct processes in root growth and development in Pisum sativum
Author(s) -
Kolbert Zsuzsanna,
Bartha Bernadett,
Erdei László
Publication year - 2008
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2008.01056.x
Subject(s) - pisum , elongation , auxin , osmotic shock , peg ratio , lateral root , osmotic concentration , horticulture , botany , sativum , biophysics , osmotic pressure , chemistry , biology , biochemistry , materials science , ultimate tensile strength , finance , arabidopsis , gene , economics , mutant , metallurgy
In this work, the effects of osmotic stress and exogenous auxin (indole‐3‐butyric acid, IBA) on root morphology and nitric oxide (NO) generation in roots were compared in pea plants. Five‐day‐old plants were treated with 0, 10 −3 , 10 −4 , 10 −5 , 10 −6 , 10 −7 , 10 −8 or 10 −9 M IBA or with PEG 6000 at concentrations that determined 0, 50, 100, 200 or 400 mOsm in the medium, during 5 days. NO generation was examined by in situ and in vivo fluorescence method. Increasing concentrations of PEG as well as IBA resulted in shortening of primary root (PR), enhancement of lateral root (LR) number and significant increase of NO generation. Time‐dependent investigations revealed that in the case of IBA treatments, the LR number increased in parallel with an intensified NO generation, while elongation of PR was not followed by changes in NO levels. Under osmotic stress, the time curve of NO development was distinct compared with that of IBA‐treated roots, because significantly, the appearance of lateral initials was preceded by a transient burst of NO. This early phase of NO generation under osmotic stress was clearly distinguishable from that which accompanied LR initiation. It is concluded that osmotic stress and the presence of exogenous auxin resulted in partly similar root architecture but different time courses of NO synthesis. We suppose that the early phase of NO generation may fulfill a role in the osmotic stress‐induced signalization process leading to the modification of root morphology.