Rapid Induction of Ion Pulses in Tomato, Cucumber, and Maize Plants following a Foliar Application of L(+)-Adenosine

Abstract

Since the discovery of the plant growth-regulating properties of TRIA, a primary alcohol that is a natural constituent of plant waxes, and its second messenger L(+)-adenosine, the rapid response kinetics to these compounds have been enigmatic (Ries and Wert, 1988;Ries, 1991).TRIA increased the dry weight, free amino acids, reducing sugars, and soluble protein of rice (Oryza sativa L.) and maize (Zea mays L.) plants within 5 min (Ries, 1991). TRIA also elicited the appearance of L(+)-adenosine in the roots of plants whose shoots were sprayed with nanomolar concentrations within 1 min (Ries and Wert, 1988). This was the first evidence that L(+)-adenosine occurred in nature. Synthetic L(+)-adenosine increased the rate of growth of rice seedlings, as measured by total dry weight gain, by more than 50% within 24 h of foliar application of 0.01 to 100.0 kg L-' (3.7 X 10-" to 10-7 M), whereas D(-)-adenosine did not affect plant growth (Ries, 1991). 49site plant part, providing it was applied 1 min prior to TRIA application (Ries and Wert, 1988). TRIA applied to oat (Avena sativa L.) or tomato (Lycopersicon esculentum Mill.) shoots connected to rice roots by a 4-mm water column also resulted in the appearance of L(+)-adenosine (TRIM) in rice roots (Ries and Wert, 1988).In an attempt to determine other physiological responses to TRIA in addition to the elicitation of L(+)-adenosine, 20-to 25-d-old tomato seedlings were sprayed with water or TRIA, and after 1 min the plants were excised. Analysis of the diffusate from the excised shoots, as determined by HPLC and atomic absorption spectrophotometry, indicated large concentration differences in organic compounds and inorganic cations (unpublished data). The largest differences were in the cation concentration of the exudate from the stump of the excised tomato plant. Thus, the objective of this research was to use this observation to further elucidate the mode of action for the rapid responses of plants to TRIA and L(+)-adenosine.We present here evidence that foliar applications of both of these compounds at nanomolar concentrations cause rapid changes in soluble Ca2+, Mg2+, and K+ concentrations within xylem exudates from the stumps of excised stems and leaves. MATERIALS A N D METHODS Plant Crowth and TreatmentTomatoes (Lycopersicon esculentum Mill. cv Sunny), cucumbers (Cucumis sativa L. cv Flurry), and maize (Zea mays L.cv Pioneer 3780) were grown in a greenhouse with approximately 16 h of supplemental light (700 pmol s-' m-', metal halide) daily. Seeds were planted in 15-cm diameter clay pots containing a soil mix, and the plants were thinned to two or three per pot 8 to 10 d after emergence. Soluble fertilizer (20 N-8.6 P-16.6 K; 1.0 g L-' Peters 20-20-20, W.R. Grace and Co., Fogelsville, PA) was applied once or twice after planting and again prior to treatment. The pots were labeled, randomized for treatments within blocks, and isolated from each other on the greenhouse bench. They were not disturbed for several hours prior to initiation of the treatments.Experiment...

Triacontanol: a potent plant growth regulator in agriculture

“…Application of even pico mole quantities of (')-adenosine (a precursor in TRIA biosynthesis and a plant growth-promoting second messenger) to the foliage of tomato (Lycopersicon esculentum Mill. ), maize (Zea mays L.), and cucumber (Cucumis sativa L.) increased the concentrations of Ca 2 ' , Mg 2 ' , and K ' by 20Á60% in the exudates obtained from the stumps of excised plants within 5 seconds of TRIA application (Ries et al 1993). …”

“…Several efforts have been made to elucidate the mechanism of TRIA action Ries 1991;Ries et al 1993). Assumption of a cascade effect led to the identification of 9-b-L (')-adenosine as a second messenger of TRIA (Ries 1991;Ries et al 1993).…”

“…Several efforts have been made to elucidate the mechanism of TRIA action Ries 1991;Ries et al 1993). Assumption of a cascade effect led to the identification of 9-b-L (')-adenosine as a second messenger of TRIA (Ries 1991;Ries et al 1993). TRIA rapidly elicits the second messenger (TRIM) in rice (Oryza sativa L.), which at nanomolar concentrations causes the plants to respond in a manner similar to TRIA (Ries 1991).…”

“…Many researchers have reported the positive role of TRIA in enhancing growth, yield, photosynthesis, nitrogen fixation, enzymes activities, free amino acids, reducing sugars, and soluble protein of plants (Ries 1991;Ries et al 1993;Nagoshi and Kawashima 1996;Borowski et al 2000;Naeem et al 2009;Aftab et al 2010;Idrees et al 2010;Naeem et al 2010. Muthuchelian et al (1997Muthuchelian et al ( , 2003 investigated the significant effect of TRIA on acid mist-treated Erythrina variegata L. seedlings with particular emphasis on growth, photosynthetic pigments, ribulose-1,5-bisphosphate (RuBPC), and photosynthetic activity.…”

“…Ries et al (1993) in their study, noticed that more information is needed regarding protocols that will ensure consistent results with both TRIA and L(')-adenosine in growth chamber, greenhouse, and field studies. However, the strong evidence is overwhelming that TRIA applied at nanomolar concentrations might increase the yield or improve the quality of various plant species.…”