21241329
not annotated - annotated - LINNAEUS only
The effect of competition from neighbours on stomatal conductance in lettuce and tomato plants.
Competition decreased transpiration from young lettuce plants after 2 days, before any reductions in leaf area became apparent, and stomatal conductance (g(s) ) of lettuce and tomato plants was also reduced. Stomatal closure was not due to hydraulic signals or competition for nutrients, as soil water content, leaf water status and leaf nitrate concentrations were unaffected by neighbours. Competition-induced stomatal closure was absent in an abscisic acid (ABA)-deficient tomato mutant, flacca, indicating a fundamental involvement of ABA. Although tomato xylem sap ABA concentrations were unaffected by the presence of neighbours, ABA/pH-based stomatal modulation is still likely to underlie the response to competition, as soil and xylem sap alkalization was observed in competing plants. Competition also modulated leaf ethylene production, and treatment of lettuce plants with an ethylene perception inhibitor (1-methylcyclopropene) diminished the difference in g(s) between single and competing plants grown in a controlled environment room, but increased it in plants grown in the greenhouse: ethylene altered the extent of the stomatal response to competition. Effects of competition on g(s) are discussed in terms of the detection of the absence of neighbours: increases in g(s) and carbon fixation may allow faster initial space occupancy within an emerging community/crop.
Ann file
T1 Species 69 76 lettuce
N1 Reference T1 Taxonomy:4236
T2 Species 81 87 tomato
N2 Reference T2 Taxonomy:4081
T3 Species 145 152 lettuce
N3 Reference T3 Taxonomy:4236
T4 Species 262 269 lettuce
N4 Reference T4 Taxonomy:4236
T5 Species 274 280 tomato
N5 Reference T5 Taxonomy:4081
T6 Species 574 580 tomato
N6 Reference T6 Taxonomy:4081
T7 Species 651 657 tomato
N7 Reference T7 Taxonomy:4081
T8 Species 963 970 lettuce
N8 Reference T8 Taxonomy:4236