DPX-1840是一種新合成的auxin運移抑制物質,於1.4×10(上標 -4)至1.4ppm之低濃度加入於花粉培養液中,即可促進番茄等七種園藝作物的花粉管伸長3至10倍。其它三種auxin運移抑制物質,naptalam, IT 3456和TIBA等,於相同之低濃度下,也一樣有促進花粉管增長之效果。比較該四種物質之促進效果大小,其順序爲naptalam≥DPX-1840>IT13456>TIBA。文中並討論此四種auxin運移抑制物質促進花粉管增長之效果與花粉管中auxin外逸之關係。
3, 3a-dihydro-2-(p-methyphenyl) -8 H-pyrazole [5, 1-a] isoindol-8-one (DPX-1840), a now synthetic auxin transport inhibitor, added to the pollen culture medium at low concentrations (1.4×10^(-4) to 1.4 ppm) greatly promoted the pollen tube elongation of tomato and those of Amaryllis app., Zygocactus truncatus, Nicotiana spp., Impatiens balsamina, Gladiolus app, and Azalea spp. as well. Three other potent auxin transport inhibitors, methyl-2-chloro-9-hydroxy flnorene-9-carboxylate (IT3456), N-naphthylphthalamic acid (Nap-talam), and 2, 3, 5-triiodobenzoic acid (TIBA), had the same promotive effects on pollen tube growth at same concentrations. Quantitative differences of pollen tube growth suggested the activity orders as follows: Naptalam≥DPX-1840>IT3456>TIBA. The relationship between promotive effects of these synthetic auxin, transport inhibitors on pollen tube growth and the auxin leaching from pollen tube was discussed.