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Photosystem II and Hypoxic Quiescence in Alligatorweed
Author(s) -
QUIMBY P. C.,
POTTER J. R.,
DUKE S. O.
Publication year - 1978
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.1399-3054.1978.tb08626.x
Subject(s) - dcmu , simazine , cutting , photosystem ii , botany , biology , oxygen , horticulture , hydrogen peroxide , alternanthera philoxeroides , chemistry , photosynthesis , biochemistry , pesticide , ecology , atrazine , organic chemistry , weed
Stem cuttings of alligatorweed [ Alternanthera philoxeroides (Mart.) Griseb.] were subjected to various light and chemical inhibitor treatments to obtain information about the physiological nature of the hypoxic quiescence induced by dark submergence. White or red light at 40 μE m −2 s −1 stimulated growth from submerged stem cuttings but far‐red at 5 μE M −2 s −1 did not. Photo‐system II inhibitors, such as 3‐(3,4‐dichlorophenyl) 1,1‐dimethylurea (DCMU) at 1.4 × 10 −5 M or 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine (simazine) at 10 −5 M , completely inhibited the growth that normally occurs in a submerged state under continuous white light at 40 μE m −2 s −1 . These concentrations of DCMU or simazine did not reduce nonphotosynthetic growth from underwater nodes of emersed stem cuttings partially exposed to air in the light for 1 week. Hydrogen peroxide at 50 mg/1 added every other day partially relieved the simazine‐induced inhibition of growth from submerged, illuminated cuttings. These data indicated that sprouting and early growth of submerged, illuminated alligatorweed depended on the oxygen produced by photosystem II to support respiration and to overcome hypoxic quiescence.