Phenolic acid allelochemicals induced morphological, ultrastructural, and cytological modification on Cassia sophera L. and Allium cepa L.

Abstract

The allelopathic potential of leaf aqueous extract (LAE) of Calotropis procera on growth behavior, ultrastructural changes on Cassia sophera L., and cytological changes on Allium cepa L. was investigated. LAE at different concentrations (0.5, 1, 2, and 4 %) significantly reduced the root length, shoot length, and dry biomass of C. sophera. Besides, the ultrastructural changes (through scanning electron microscopy, SEM) induced in epidermal cells of 15-day-old seedlings of Cassia leaf were also noticed. The changes induced were shrinking and contraction of epidermal cells along with the formation of major grooves, canals, and cyst-like structures. The treated samples of epidermal cells no longer seem to be smooth as compared to control. LAE at different concentrations induces chromosomal aberrations and variation in shape of the interphase and prophase nucleus in A. cepa root tip cells when compared with control groups. The mitotic index in treated onion root tips decreased with increasing concentrations of the extracts. The most frequent aberrations were despiralization at prophase with the formation of micronuclei, sticky anaphase with bridges, sticky telophase, C-metaphase, etc. The results also show the induction of ghost cells, cells with membrane damage, and cells with heterochromatic nuclei by extract treatment. Upon HPLC analysis, nine phenolic acids (caffeic acid, gentisic acid, catechol, gallic acid, syringic acid, ellagic acid, resorcinol, p-coumaric acid, and p-hydroxy benzoic acid) were identified. Thus, the phenolic acids are mainly responsible for the allelopathic behavior of C. procera.

Determination of allelopathic properties of Acacia catechu (L.f.) Willd.

“…This type of concentration-dependent inhibition has been reported by Sinha and Samar (2004), Swain et al (2005), Ishak and Sahid (2014), Gulzar et al (2016), Al-Harbi (2018, Mushtaq et al (2018), Zaman et al (2020), andHossen et al (2020). The extracts of A. catechu had different inhibitory activities on different tested plants, showing that the growth inhibitory effects of this plant's extracts depended on the target plant species.…”

Study of the allelopathic activity of Garcinia pedunculata Roxb

“…Several previous studies have also reported that the inhibitory effect of plant extracts is more pronounced on root growth than shoot growth (Liu et al, 2018;Sbai et al, 2016). Such root inhibition might be due to the higher permeability of root tissue, which allows more allelochemicals to enter the roots compared with shoots because the shoot surface is covered with a well-developed cuticular layer, whereas the root surface lacks this layer (Gulzar et al, 2016;Yoshimura et al, 2011). Another possible explanation is that root growth largely depends on cell proliferation, which is All the test plant species were treated at the concentrations of 0.001, 0.003, 0.01, 0.03, 0.1, and 0.3 g dry weight equivalent extract of G. pedunculata/mL.…”

Allelopathic Potential of Etlingera coccinea (B.) Sakai & Nagam on Seed Germination and Growth of Mung Bean and Siam Weed

“…Moreover, the cotyledon of seeds appeared abnormal compared to root formation in the seedlings in the control. Primary growth of plants is extremely sensitive to the concentration of bioactive compounds in their surrounding [17]. The effect of allelochemicals in E. coccinea may have led to the metabolic impairment of mung bean which resulted decreasing formation of normal root.…”