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Abscisic acid increases anaerobic tolerance in alfalfa seedlings
Author(s) -
KatoNoguchi Hisashi
Publication year - 1999
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 - 10.1034/j.1399-3054.1999.100404.x
Subject(s) - abscisic acid , anaerobic exercise , botany , biology , chemistry , horticulture , biochemistry , physiology , gene
In order to clarify the effect of abscisic acid (ABA) on anaerobic tolerance in alfalfa ( Medicago sativa L.), the seedlings were subjected to anaerobic stress after pretreatment with ABA. At concentrations> 1 μ M , ABA pretreatment increased the root viability of the seedlings to anaerobic stress and the viability increased with increasing ABA doses. At 100 μ M ABA, the viability was 2.5‐fold greater as compared with that of control seedlings. Roots of the seedlings rapidly lost ATP under the anaerobic stress; however, the decrease in ATP was much slower in the ABA‐pretreated seedlings than the control seedlings. At 12 h after onset of the stress, ATP concentrations in the roots of 100 and 10 μ M ABA‐pretreated seedlings were 2.7‐ and 2.0‐fold that of the control seedlings, respectively. During the period of ABA pretreatment under aerobic condition, ABA increased alcohol dehydrogenase (ADH, EC 1.1.1.1) activity in the roots until 12 h and then leveled off. The maximum ADH activities were 4.3‐ and 2.8‐fold that in the roots of the control seedlings for 100 and 10 μ M ABA‐pretreated seedlings, respectively. After being subjected to the anaerobic stress, both ADH activities in the roots of the ABA‐pretreated and the control seedlings increased but the differences in their activity remained. These results suggest that ABA pretreatment may maintain ATP level due to induction of ADH activity, which may be one of the causes of increasing anaerobic tolerance in the seedlings.