Effects of 3,4-Benzopyrene on the adventitious root differentiation of in vitro culture seedlings of Triarrherca sacchariflora

Key message 3,4-Benzopyrene might be an auxin-like substance with the positive biological effect on the adventitious root differentiation via regulating some endogenous hormones of in vitro cultural seedlings of T. sacchariflora. Polycyclic aromatic hydrocarbons (PAHs) present a significant threat to human health, in which 3,4-Benzopyrene as one of the three major carcinogens has been widely studied, while there are few researches of roots differentiation under 3,4-Benzopyrene exposure for understanding the mechanism of its phytoremediation. In this paper, the adventitious root differentiation of Triarrherca sacchariflora in vitro culture seedlings was observed under 3,4-Benzopyrene exposure. The results showed that 2.0 mg/L 3,4-Benzopyrene had significant positive effects on the adventitious root differentiation, while the higher dosage of 20.0 mg/L showed inhibition effects. 3,4-Benzopyrene could cause the remarkable reduction of the endogenous IAA and the ratios of IAA/ZR, IAA/DHZR, IAA/iPA and IAA/(ZR+DHZR+iPA) in stem explants of in vitro cultural seedlings of T. sacchariflora. The responses of coleoptile elongation of Zea mays and the DR5::GUS reporter gene of Arabidopsis thaliana to 3,4-Benzopyrene exposure were all positive comparing with the controls. It could be inferred from the results that the 3,4-Benzopyrene may be an auxin-like substance. In our knowledge, it was the first report concerning the 3,4-Benzopyrene with respect to the adventitious root differentiation of T. sacchariflora in vitro culture seedlings and its auxin-like biological effect analysis. It is the meaningful step to further understanding the 3,4-Benzopyrene effects on the plant endogenous signal substances that regulate the plant growth and development which closely related to the phytoremediation of PAHs.

Automated summary

The study suggests that 3,4-benzopyrene may act as an auxin-like substance, positively influencing adventitious root differentiation in Triarrherca sacchariflora in vitro culture seedlings. While lower concentrations had a significant positive effect, higher dosages showed inhibitory effects. This research is the first to investigate the effects of 3,4-benzopyrene on the plant endogenous signal substances involved in regulating plant growth and development, shedding light on its role in phytoremediation of PAHs.