A Polypeptide from Tomato Leaves Induces Wound-Inducible Proteinase Inhibitor Proteins

Abstract

Defensive genes in plants can be activated by several different types of nonpeptide signaling molecules. An endogenous polypeptide, consisting of 18 amino acids, was isolated from tomato leaves and was able at very low concentrations to induce the synthesis of two wound-inducible proteinase inhibitor proteins when supplied to young tomato plants. The sequence of the polypeptide was determined, and an identical polypeptide was synthesized that possessed full inducing activity. These data establish that a polypeptide factor can initiate signal transduction to regulate the synthesis of defensive proteins in plant tissues.

Is membrane potential involved in calmodulin gene expression after external stimulation in plants?

“…Three different hypothesis have been proposed to explain long-distance information transfer: (i) it has been suggested that a mobile chemical signal is the causal agent and candidates such as oligosaccharides [4], abscisic acid [5] and systemin [6] have been proposed; (ii) it has also been shown that one response to external stimuli in higher plants is the elicitation and the spreading of a variation in the transmembrane electrical potential and several authors suggested that these electrical signals could be the 'information' carrier [1,3,7,8]; (iii) it has been demonstrated that hydraulic signals are transmitted from damaged tissue [9,10] and it has been proposed that hydraulic signals could form part of a widespread mechanism for coordination of plant responses [11].…”

Variation potential in higher plants: Mechanisms of generation and propagation

“…This substance must: (i) be synthesized quickly in response to damage, (ii) induce electrical reactions, and (iii) propagate easily in plants. Oligosaccharides of broken cell walls, 66 systemin, 67 jasmonate, 18,68 salycilic acid, 69 ethylene 19,70 and abscisic acid 1,2 are considered to be potential wound substances. In recent studies, 71 hydrogen peroxide (H 2 O 2 ) has been shown to propagate from the damage zone and induce an electrical reaction.…”

Plant communication – why should plants emit volatile cues?

“…Early reports of induced resistance being effective at reducing herbivore populations portrayed plants as responding systemically to herbivore damage (Karban and Carey 1984;Haukioja and Neuvonen1985;Pearce et al 1991). However, subsequent work revealed that induced resistance was stronger in some parts of the plant, particularly those close to the site of damage (Tuomi et al 1988;Orians et al 2000).…”