The effect of competition from neighbours on stomatal conductance in lettuce and tomato plants

Abstract

Competition decreased transpiration from young lettuce plants after 2 days, before any reductions in leaf area became apparent, and stomatal conductance (gs) 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. Competitioninduced 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 gs 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 gs are discussed in terms of the detection of the absence of neighbours: increases in gs and carbon fixation may allow faster initial space occupancy within an emerging community/crop.

Effect of ethylene perception inhibitor on growth, water relations, and abscisic acid content in wheat plants under water deficit

“…In 7 days after the start of seed germination, some plants were treated with 1 MCP as described in [15]. 1 MCP was produced from its precursor obtained as a gift from Smart Fresh, AgroFresh Inc. (United States).…”

“…To do this, before watering cessation, wheat plants were treated with the inhibitor of ethylene per ception, 1 methylcyclopropene (1 MCP) [15]. According to Sisler [16], a single plant treatment with this very active compound prevented the occurrence of ethylene effects, at least, for several days, due to its irreversible binding to the ethylene receptors [17].…”

“…Over the next four days, the sand moisture was maintained at the level of 80-60% (after watering and before following watering) of full sand capacity by double watering (in the morning and evening) with the Hoagland-Arnon solution. The amount of the nutrient solution required was calcu lated on the basis of vessel weighing.In 7 days after the start of seed germination, some plants were treated with 1 MCP as described in [15]. 1 MCP was produced from its precursor obtained as a gift from Smart Fresh, AgroFresh Inc. (United States).…”

Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

“…Regulation of stomatal movement under WD is not solely regulated by ABA; evidences also suggests a role for ethylene (Dodd, 2003;Vysotskaya et al, 2011).…”

The effect of 1-methylcyclopropene on the components of pro- and antioxidant systems of wheat and the development of defense reactions in fungal pathogenesis

“…The con ditions of growing were as follows: temperature [21]. A part of the leaves were treated with 0.1 g/L 1 MCP ("AgroF resh Inc, Spring House PA," United States) 5-6 h after the adaptation period and then immediately closed and kept in the dark [22]. After 24 h, the incubation leaves were infected with a suspension of pyknospores of the aggressive strain of S. nodorum (10 5 spores/mL) obtained from the laboratory collection and transferred into the KS 200 SPU climatic chamber.…”