title: ABA, GA(3), and nitrate may control seed germination of Crithmum maritimum (Apiaceae) under saline conditions.
abstract: Impaired germination is common among halophyte seeds exposed to salt stress, partly resulting from the salt-induced reduction of the growth regulator contents in seeds. Thus, the understanding of hormonal regulation during the germination process is a main key: (i) to overcome the mechanisms by which NaCl-salinity inhibit germination; and (ii) to improve the germination of these species when challenged with NaCl. In the present investigation, the effects of ABA, GA(3), NO(-)(3), and NH(+)(4) on the germination of the oilseed halophyte Crithmum maritimum (Apiaceae) were assessed under NaCl-salinity (up to 200 mM NaCl). Seeds were collected from Tabarka rocky coasts (N-W of Tunisia). The exogenous application of GA(3), nitrate (either as NaNO(3) or KNO(3)), and NH(4)Cl enhanced germination under NaCl salinity. The beneficial impact of KNO(3) on germination upon seed exposure to NaCl salinity was rather due to NO(-)(3) than to K(+), since KCl failed to significantly stimulate germination. Under optimal conditions for germination (0 mM NaCl), ABA inhibited germination over time in a dose dependent manner, but KNO(3) completely restored the germination parameters. Under NaCl salinity, the application of fluridone (FLU) an inhibitor of ABA biosynthesis, stimulated substantially seed germination. Taken together, our results point out that NO(-)(3) and GA(3) mitigate the NaCl-induced reduction of seed germination, and that NO(-)(3) counteracts the inhibitory effect of ABA on germination of C. maritimum.
authors.affiliation: Centre de biotechnologie à la technopole de Borj Cedria, Hammam-Lif, Tunisia. atbdllh@yahoo.fr
authors.forename: Abdallah
authors.initials: A
authors.lastname: Atia
authors.forename: Ahmed
authors.initials: A
authors.lastname: Debez
authors.forename: Zouhaier
authors.initials: Z
authors.lastname: Barhoumi
authors.forename: Abderrazak
authors.initials: A
authors.lastname: Smaoui
authors.forename: Chedly
authors.initials: C
authors.lastname: Abdelly
mesh_terms: D000040:Abscisic Acid / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D000643:Ammonium Chloride / Q000494:pharmacology; D019661:Apiaceae / Q000187:drug effects / Q000502:physiology*; D004347:Drug Interactions; D018525:Germination / Q000187:drug effects / Q000502:physiology*; D005875:Gibberellins / Q000494:pharmacology / Q000502:physiology*; D009566:Nitrates / Q000494:pharmacology / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D017680:Potassium Compounds / Q000494:pharmacology; D011728:Pyridones / Q000494:pharmacology; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D054712:Salinity; D055051:Salt-Tolerant Plants / Q000187:drug effects / Q000502:physiology*; D012639:Seeds / Q000187:drug effects / Q000502:physiology*; D014416:Tunisia
chemical_list: D005875:Gibberellins; D009566:Nitrates; D017680:Potassium Compounds; D011728:Pyridones; D012462:Saline Solution, Hypertonic; D000643:Ammonium Chloride; C013351:fluridone; D011189:Potassium Chloride; D000040:Abscisic Acid; C031618:sodium nitrate; C007842:gibberellic acid; C023844:potassium nitrate