Morphological, Anatomical, Physiological and Biochemical Changes during Adventitious Roots Formation of Bougainvillea buttiana ‘Miss Manila’

Abstract

Bougainvillea, a widely used ornamental plant, is mainly propagated by cuttings and tissue culture. Still, large-scale production of Bougainvillea is often difficult because of rooting issues. Therefore, based on an early establishment of the regeneration system for tissue culture in Bougainvillea by our research team, we further studied its rooting mechanism. It was observed that the morphology and anatomical structure of Bougainvillea buttiana ‘Miss Manila’ contained endogenous hormones, such as indole-3-acetic acid (IAA), abscisic acid (ABA), gibberellic acid (GA3), and zeatin-riboside (ZR), including peroxidase (POD), polyphenol oxidase (PPO), and IAA-oxidase (IAAO) activities. Following the culture, Days 0–15 consisted of the induction and initiation stages, while Days 15–25 included the expression stages. No latent root primordium was found in the Bougainvillea plantlet, which belonged to the induced rooting type. The root primordium was derived from callus cells generated by divisions of parenchyma cells in the basic tissues. It was found that the changes in the POD, PPO, and IAAO activities were closely related to the formation of adventitious roots (AR), in which the highest rooting values occurred during the transition from the initiation stage to the expression stage, whereas the endogenous IAA and ABA contents had negative and positive correlations during the induction, initiation, and expression stages.; The values of GA3 and ZR also peaked during the transition from the initiation to the expression stage. ZR and GA3 were found to promote adventitious root formation, while ABA inhibited it. The IAA/ABA, ABA/ GA3, and IAA/ZR ratios also shifted at the onset of the expression stage of AR, indicating these values were closely related to their occurrence. Overall, this study provides the basis for further research considering AR formation in Bougainvillea, and the propagation of various Bougainvillea varieties.

Plant Regeneration via Organogenesis in Jerusalem Artichokes and Comparative Analysis of Endogenous Hormones and Antioxidant Enzymes in Typical and Atypical Shoots

“…It has been reported that there is a direct or indirect correlation between different endogenous hormones and antioxidant enzymes, as well as other physiological substances, which collectively affects differentiation and morphogenesis during tissue culture [33,34]. In this study, the correlation analysis showed that the activity of all three enzymes was positively correlated with the content of IAA and ABA while negatively correlated with the content of 6-BA, ZT, and GA 3 .…”

“…Antioxidant enzymes can scavenge reactive oxygen species and lipid peroxidation products, and their activity is commonly enhanced when suffering from biotic or abiotic stresses [32]. Like excess PGRs, when under specific in vitro culture conditions, the in vitro cultures may suffer from oxidative stress and, consequently, will regulate the endogenous hormone content and antioxidant enzyme activity to alleviate oxidative damage [33,34]. Schnablova et al [35] reported that the overproduction of endogenous cytokinins increased the activity of some antioxidant enzymes involved in lignification, such as syringaldazine peroxidase and guaiacol peroxidase.…”

Effects of Different Growth Hormones on Rooting and Endogenous Hormone Content of Two Morus alba L. Cuttings

“…During plant cuttings, the ratio of endogenous hormone levels bears close relation with the formation of adventitious roots [58]. According to Quan et al [59], the higher the values of IAA/ABA and IAA/ZR are, the easier it is to form roots.…”

Acute NO2 Stress Shortens the Median Survival Period of Bougainvillea glabra ‘Elizabeth Angus’ by Disrupting Tissue Structure and Photosynthetic Response Centers

“…It is extensively cultivated in urban landscaping projects in tropical and subtropical regions due to its exceptional ornamental value and diverse potential applications. Bougainvillea has several garden advantages, including rapid growth, high organ differentiation [20], and easy reproduction [21,22]. In addition, in terms of ecological regulation, Bougainvillea has a certain tolerance and regulation ability to water bodies [23,24], air [7,25,26], and soil [27].…”