Auxin and cytokinin mediated regulation involved in vitro organogenesis of papaya

Genome-Wide Identification and Expression Pattern Profiling of the Aquaporin Gene Family in Papaya (Carica papaya L.)

Aquaporins (AQPs) are mainly responsible for the transportation of water and other small molecules such as CO2 and H2O2, and they perform diverse functions in plant growth, in development, and under stress conditions. They are also active participants in cell signal transduction in plants. However, little is known about AQP diversity, biological functions, and protein characteristics in papaya. To better understand the structure and function of CpAQPs in papaya, a total of 29 CpAQPs were identified and classified into five subfamilies. Analysis of gene structure and conserved motifs revealed that CpAQPs exhibited a degree of conservation, with some differentiation among subfamilies. The predicted interaction network showed that the PIP subfamily had the strongest protein interactions within the subfamily, while the SIP subfamily showed extensive interaction with members of the PIP, TIP, NIP, and XIP subfamilies. Furthermore, the analysis of CpAQPs' promoters revealed a large number of cis-elements participating in light, hormone, and stress responses. CpAQPs exhibited different expression patterns in various tissues and under different stress conditions. Collectively, these results provided a foundation for further functional investigations of CpAQPs in ripening, as well as leaf, flower, fruit, and seed development. They also shed light on the potential roles of CpAQP genes in response to environmental factors, offering valuable insights into their biological functions in papaya.

Integrated Proteomic and Metabolomic Analyses Provide Insights Into Acquisition of Embryogenic Ability in Agapanthus praecox

Somatic embryogenesis (SE) is an ideal model for plant cell totipotency. Transition from somatic cells to embryogenic cells is the key to SE. The poor frequency of embryogenic callus (EC) induction has limited the application of SE in many plants, such as Agapanthus praecox. We performed large-scale, quantitative proteomic and metabolomic analyses with different callus differentiation directions (SE and organogenesis) and stages (initial SE and repetitive SE) to better understand the morphological, physiological, and molecular characteristics of the acquisition of embryogenic ability in A. praecox. Integrated proteomic and metabolomic analyses suggested that callus differentiation direction was potentially regulated by pathways related to carbohydrate and energy metabolism (fatty acid metabolism, pyruvate metabolism, glycolysis/gluconeogenesis, pentose and glucuronate interconversions, starch and sucrose metabolism, galactose metabolism, carbon fixation pathways in prokaryotes, carbohydrate digestion and absorption, and fructose and mannose metabolism), chromatin accessibility and DNA methylation, reactive oxygen species responses and resistance (ascorbate and aldarate metabolism), and plant hormonal signaling. As a validation, we found that carbon source combination and plant hormone regulation in the culture medium significantly affected the acquisition of embryogenic ability, thereby inducing EC. Interestingly, plant hormonal signaling-related genes showed different expression patterns significantly when callus cultured with different carbon sources. Thus, our results suggested that energy supply and hormone signal transduction seemed to cooperatively contribute to the activation of embryogenic ability. Altogether, this study revealed valuable information regarding the molecular and biochemical changes that occurred during EC induction and provided valuable foundation for comprehensive understanding of the mechanisms associated with SE and organogenesis in A. praecox.