Ultrastructural and hormonal changes related to harmaline-induced treatment in Arabidopsis thaliana (L.) Heynh. root meristem

Application of Indole-Alkaloid Harmaline Induces Physical Damage to Photosystem II Antenna Complexes in Adult Plants of Arabidopsis thaliana (L.) Heynh

“…The results highlighted and confirmed in situ the strong in vitro phytotoxic potential of this natural molecule on A. thaliana metabolism. 17 In particular, both watering and spraying treatments caused evident phytotoxic effects already at very low concentrations if compared to other phytotoxic molecules reported in the literature. 20−23 Moreover, the results suggest that harmaline could act by inducing an alteration of the plant-water status followed by the altered redox status with the consequent physical damage to the photosynthetic machinery, affecting plant growth and development.…”

“…All the treatments were applied by watering (sub-irrigation) or spraying. The concentrations were selected based on the IC 50 value obtained in the in vitro harmaline bioassays published by A ́lvarez-Rodri ́guez et al 17 Trays for watering experiments were irrigated every other day with 350 mL of 50% Hoagland solution, enriched with different harmaline solutions, for 21 days. Trays for spraying experiments were also watered with 350 mL of 50% Hoagland solution every other day for 21 days, but the leaves were daily sprayed with 10 mL of ultrapure water in the case of the control, and 10 mL of each harmaline solution in the case of treatments until the leaves were homogeneously covered with tiny droplets (both the control and treatments were supplemented with 0.001% of Tween-20).…”

“…This bioactive molecule is mainly found in the plant species Peganum harmala, Banisteriopsis caapi, or Passiflora incarnata L . Its phytotoxicity has already been described in vitro on Arabidopsis thaliana seedlings, pointing out strong aberrations on the anatomy and ultrastructure of the root meristem, mediated by an alteration of the root hormonal balance . However, only few information is available about the effects of harmaline on adult plants.…”

“…This bioactive molecule is mainly found in the plant species Peganum harmala, 14 Banisteriopsis caapi, 15 or Passiflora incarnata L. 16 Its phytotoxicity has already been described in vitro on Arabidopsis thaliana seedlings, pointing out strong aberrations on the anatomy and ultrastructure of the root meristem, mediated by an alteration of the root hormonal balance. 17 evaluated harmine and harmaline effects on root and shoot length through inhibitory assays with different crops, such as wheat or lettuce, nothing related to internal changes caused in adult plant metabolism has been studied up to now. The mode of action of several specialized metabolites with herbicidal activities has already been studied on A. thaliana adult plants over the past few years.…”

Short-Term Effects of Trans-Cinnamic Acid on the Metabolism of Zea mays L. Roots

“…Harmaline, for example, is an indole alkaloid that alters the balance between the phytohormones auxin, cytokinin and ethylene, altering the development of Arabidopsis thaliana (L.), Heynh. seedlings [ 5 ]. Another indole alkaloid such as norharmane can decrease the growth of A. thaliana seedlings by altering the distribution of auxin transporter proteins (PINs) [ 6 ], and of adult A. thaliana plants by generating water stress when applied by irrigation, while inhibiting the germination and growth of some weed species [ 7 ].…”