The natural compound trans‐chalcone induces programmed cell death in Arabidopsis thaliana roots

Abstract

Chalcone (1,3-diphenyl-2-propen-1-one) is an aromatic ketone precursor of important molecules in plants such as flavonoids or anthocyanins. Its phytotoxicity has been demonstrated on different plant species, but to date little is known about the mechanisms of action of this secondary metabolite at plant cellular level. Detailed analysis by light and transmission electron microscopy (TEM) was conducted to examine the root meristems' ultrastructure of control and chalcone-treated Arabidopsis seedlings. Mitochondrial dysfunction was analysed by measuring mitochondrial membrane potential with JC-1 fluorochrome. Finally, acridine orange/ethidium bromide staining was used for the detection of programmed cell death. Microscopy revealed tissue alterations, inhibition of root hair formation and important changes after 7 and 14 d at the chalcone IC50 value. Chalcone-treated cells showed signs of programmed cell death such as mitochondrial condensation, disruption of organelles and chromatin fragmentation. Acridine orange/ethidium bromide staining confirmed the programmed cell death, which could be induced by the reduction of mitochondrial transmembrane potential (DYm) that was detected after chalcone treatment. These results confirm the phytotoxic activity of chalcone on Arabidopsis seedlings, the alteration of mitochondrial membrane potential and the induction of programmed cell death.

Biological Activities and Novel Applications of Chalcones

“…Consistent with other assays, trans-chalcone inhibited root growth at very low concentrations (Díaz-Tielas et al, 2012), with a 50% reduction of root growth (IC 50 ) at only 35 μM and 80% reduction (IC 80 ) at 73 μM. Furthermore, chalcone induced PCD in Arabidopsis roots and loss of photosynthetic pigments at only 35 μM.…”

“…As lignin synthesis is necessary for plant growth and development, these studies suggested that the inhibition of the enzyme 4CL by chalcones, and the consequent lower rate in the synthesis of lignin, may be the reason for the inhibited plant growth. Further studies demonstrated a correlation between the inhibition of root growth and the strong decline in the activity of root peroxidases (Díaz-Tielas et al, 2012), implicated in lignin biosynthesis and ROS production (Chen and Schopfer, 1999), compounds necessary for cell growth and differentiation.…”

“…Furthermore, some chalcones may have dual functions, inducing PCD in some cell types, and preventing against oxidative cytotoxicity in others (Lee et al, 2015;Zhong et al, 2015). Chalcones induce also programmed cell death in other eukaryotes, such as the protozoan Plasmodium falciparum (Sharma et al, 2012), and the plant Arabidopsis thaliana (Díaz-Tielas et al, 2012).…”

Effects and identification of chemical compounds released from the invasiveAcacia dealbataLink

“…Abnormal cell division of plants with aberrant formations and less root hairs were characteristic of allelochemical-treated roots. [43] Changes in auxin content in treated roots could have played a role in the absence of root hairs, [44] as root hairs formation is sensitive to hormonal and environmental factors [45] and the local presence of auxin and expansions are required for the growth and development of root hairs.…”

Nostoc sp. extract induces oxidative stress-mediated root cell destruction in Mimosa pigra L.

“…Continuous damage of mitochondria becomes irreversible and ensures cell death (Van Loo et al [2002]). Diaz-Tielas et al ([2012]) showed that alteration of mitochondrial membranes, swollen mitochondria, and the induction of irreversible cell death were due to the phytotoxicities of chalcone on Arabidopsis thaliana (L.) Heynh. seedlings.

Figure 7 TEM micrographs of M .

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