Biochemical and Physiological Changes during Early Adventitious Root Formation in Chrysanthemum indicum Linné Cuttings

Influence of low-cost Thai leucoxene minerals on the growth, bioactive compounds, and antibacterial activities of Chrysanthemum indium L. cuttings in in vitro culture

The effects of low-cost Thai leucoxene mineral (LM) at different concentrations (10, 20, 30, 40, 50, and 60 mg/L) on the growth and antibacterial properties of Chrysanthemum indium L. cuttings under in vitro were evaluated. The primary chemical composition of LM was approximately 86% titanium dioxide (TiO2), as determined by dispersive X-ray spectroscopy. The crystalline structure, shape, and size were investigated by X-ray diffraction and scanning electron microscopy. LM at 40 and 50 mg/L significantly increased plant height, leaf number, node number, and fresh and dry weight. These growth-promoting properties were accompanied by improved chlorophyll and carotenoid contents and antioxidant enzyme activities and reduced malondialdehyde levels. Additionally, LM treatment at 40 and 50 mg/L had positive effects on antibacterial activity, as indicated by the lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. The high levels of phenolic compounds in the plants contributed to the MIC and MBC values. In conclusion, these findings provide evidence for the effectiveness of LM in enhancing the growth of Chrysanthemum plants in in vitro culture and improving their antibacterial abilities.

BpWOX11 promotes adventitious root formation in Betula pendula

Adventitious root formation is a key step in vegetative propagation via cuttings. It is crucial for establishing birch plantations and preserve birch varieties. Although previous studies have highlighted role of WOX11 in controlling adventitious root formation, no such study has been conducted in birch. Understanding the mechanism of adventitious root formation is essential for improvement of rooting or survival rate using stem cuttings in birch. In this study, we cloned BpWOX11 and produced BpWOX11 overexpression (OE) transgenic lines using the Agrobacterium-mediated plant transformation. OE lines exhibited early initiated adventitious root formation, leading to increase the rooting rate of stem cuttings plants. RNA sequencing analysis revealed that OE lines induced the gene expression related to expansin and cell division pathway, as well as defense and stress response genes. These may be important factors for the BpWOX11 gene to promote adventitious root formation in birch cuttings. The results of this study will help to further understand the molecular mechanisms controlling the formation of adventitious roots in birch.