Hydrogen Sulfide: Effects on the Physiology of Rice Plants and Relation to Straighthead Disease

Mechanism for the hydrogen sulfide‐induced growth limitation in wetland macrophytes

“…Carlson and Forrest 1982;King et al 1982:;Howes et al 1985). This phytotoxin has been shown to reduce growth in several marine and freshwater marsh species (Joshi et al 1975;Ingold and Havill 1984) but the underlying physiological mechanism by which this growth inhibition occurs, particularly in wetland plants, is not well understood.…”

Gas transport through rice

“…For example, the N 2 content and the redox potential of flooded soil can be affected (19,21,26). The concentration of certain toxic substances such as organic compounds, sulfides, manganese, and ferrous iron may be reduced through the oxidizing power of the rice roots (11,13,14,19). Nitrogen fixation, denitrification, and methane formation in the rhizosphere may also be influenced (20).…”

“…Rice varieties differ in their ability to release oxidant into the rhizosphere (4,10,11,(13)(14)(15)(16)18), but in certain cases this may be more a reflection of differences in respiration rates rather than in capacity to transport oxygen (5,6). Environmental conditions, particularly flooding, influence the development of a gas transport system in rice (2,3,5,15).…”

Shoreline algal wash as a factor in reed decline in Lake Constance-Untersee

“…< + 4, and pe? < -3, respectively, see Frevert, 1983) to give toxie eoncentrations for the adventitious roots of Phragmites (Joshi et al, 1975;Mendelssohn et al, 1982).…”

“…The clumps were al10wed to deeompose anaerobicalIy for 6 weeks (20 0 C. darkness). The suspension was then filtered stepwise through 2 mm to 0.2 jlm-sieves and membrane filters, respectively; al1 steps were performed in a cold ehamber (4 0 C), the solution eontinuously exposed to the air to remove Fe 2 + and H 2 S-S. Hydrogen sulfide is known to be toxie to plant roots (Joshi et al, 1975;Mendelssohn et al, 1982), henee it was neeessary to eliminate free sulfide from the test solutions by ventilation to demonstrate the existenee of other toxie eomponents. Toxie Fe 2 + was oxidised and the ferric oxides were retained on the 0.2 J.l-filter.…”