Specificity of 1-triacontanol as a plant growth stimulator and inhibition of its effect by other long-chain compounds

Abstract

The effect of several analogs of 1-triacontanol (TRIA), differing in C-chain length (16-32), the position of the hydroxyl group and the terminal functional group, were tested alone and in combination with TRIA on the growth of rice (Oryza sativa L.), maize (Zea mays L.) and tomato (Lycopersicon esculentum Mill.) seedlings. Applied alone, none of the compounds caused an increase in growth; thus, chain length (30 C) and presence and position (terminal) of the hydroxyl group appear to be specific for the growth-promoting activity of TRIA. When applied simultaneously with TRIA, all analogs inhibited the response to the latter in all three test plants, whether applied in the nutrient solution, as foliar spray or by seed soaking. 1-Octacosanol inhibited the response of rice seedlings to 2.3 x 10(-8) M TRIA at concentrations as low as 2.4 x 10(-12) M. Thus preparations of TRIA and application equipment must be free from trace amounts of other long-chain compounds if they are to be used to increase plant growth.

9-?-L(+) Adenosine: A new naturally occurring plant growth substance elicited by triacontanol in rice

“…seedlings, within 10 min of a foliar application of 1 .0 tg/L [15] . Octacosanol (OCTA), a n-C 28 alcohol applied to either rice roots or shoots 1 min prior to TRIA treatment of the opposite organ of the seedling inhibits this response [7,15] . TRIA quickly elicits a new growth substance (TRIM) that moves rapidly (within 1 min) throughout the plant resulting in stimulation of growth (dry weight increase) and water uptake [16] .…”

Rapid Growth and Apparent Total Nitrogen Increases in Rice and Corn Plants following Applications of Triacontanol

“…Jones et al. (11) demonstrated that a chain length of 30 carbons with a terminal hydroxyl group was specific for TRIA's growthpromoting activity. Tests of the growth-promoting activity of TRIA analogs, varying in chain length from 16 to 32 carbons, proved negative.…”

“…Tests of the growth-promoting activity of TRIA analogs, varying in chain length from 16 to 32 carbons, proved negative. In fact, these compounds resulted in inhibition of the TRIA response when applied simultaneously (11). Thus, the primary alcohols, octocosanol (28-C) and tetracosanol (24-C), are excellent inhibitors of the TRIA response at equimolar rates.…”

Effect of Triacontanol on Chlamydomonas

“…6) Octacosanol Inhibition. Octacosanol, a 28-carbon straightchain primary alcohol, which inhibits the effects of TRIA on higher plants ( 13), also inhibited the increase in photosynthetic CO2 assimilation in TRIA-treated Chlamydomonas cells (Table IV). Octacosanol alone had no effect on photosynthetic CO2 assimilation; therefore, the effect ofTRIA on this process appears to be specific for TRIA.…”