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The effect of light and exogenous gibberellic acid on respiration pathways during germination of tomato seeds
Author(s) -
Gui MeiXiang,
Wang XiaoMing,
Huang WeiYu
Publication year - 1991
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.1399-3054.1991.tb08750.x
Subject(s) - respiration , gibberellic acid , iodoacetic acid , germination , respiration rate , gibberellin , dehydrogenase , lycopersicon , darkness , biology , botany , horticulture , chemistry , biochemistry , enzyme
Tomato (Lycopersicon esculenlum Mill. cv. Taiwan Red) seeds are typical lightsensitive seeds where light requirement can be substituted by gibberellic acid (GA 3 ). During the initial stage of germination, the hexose monophosphate pathway (HMP) in seeds incubated for 24 h under white light or 12 h in 0.3 mW GA 3 solution acidified with 1 M HCI for 1 h in the dark (HCl→GA 3 ) was much greater than in seeds incubated for 24 h in the dark. The results were obtained from measurements of the respiration rate by man metric method of Warburg with or without iodoacetic acid, and from activities of glucose‐6‐phosphate dehydrogenase (EC 1.1.1.49) and aldolase (EC 4.1.2.13). Although the HMP tended to decrease at the later stage (72 h under white light or in the dark, or 36 h in HCl→GA 3 ), it remained greater in light‐ than in dark‐incubated seeds. CN‐resistant respiration increased from 27–30% to 57–64% of the total respiration in seeds incubated under white light or in HCI→GA 3 , while respiration of non‐germinating, dark‐incubated seeds remained zero. Benzohydrox–amic acid (BHAM), an inhibitor of the alternative pathway, inhibited both respiration and seed germination. It is concluded that the enhancement of HMP and the CN–resistant pathways are both controlled by P fr , but there is no direct connection between them.