Fluoranthene-induced production of ethylene and formation of lysigenous intercellular spaces in pea plants cultivated in vitro

The effect of increasing concentration of polycyclic aromatic hydrocarbon (PAH) fluoranthene (FLT; 0.1, 1 and 5 mg l(-1)) on the growth, ethylene production and anatomy of stems of 21-day-old pea plants cultivated in vitro in MS medium, with or without FLT, enriched with 0.1 mg l(-1) indole-3-acetic acid (IAA) or with combination of 0.1 mg l(-1) IAA + 0.1 mg l(-1) N-6-benzyladenine (BA) were investigated. The low concentration of 0.1 mg l(-1) FLT, in both IAA- and IAA + BA-treated plants, significantly stimulated the growth of pea callus, while higher concentrations 1 mg l(-1) and especially 5 mg l(-1) FLT significantly inhibited it. Pea shoots were significantly influenced only after application of 5 mg l(-1) FLT in IAA treatment. Significantly increased production of ethylene was found in IAA + BA treatments in all concentrations of FLT, whereas in IAA treatments in 1 and 5 mg l(-1) FLT. The lysigenous aerenchyma formation in the cortex of pea stems significantly increased in all FLT treatments and its highest proportion was found in plants exposed to 1 mg l(-1) FLT.