Genes

Background: Light is an important environmental signal that regulates the growth and metabolism of fungi. This study aims to reveal the molecular regulatory mechanism of different light durations on the growth activity of Poria cocos. Methods: By setting up three groups of light treatment: 0 days (sample 1), 15 days (sample 2), and 30 days (sample 3), and combining transcriptome sequencing (RNA-seq) with qRT-PCR for verification, the effects of light on the gene expression of Poria cocos (Poria cocos (Schw.) Wolf) were systematically analyzed. Results: A total of 4332 differentially expressed genes (DEGs) were identified in this study. Among them, the blue light-responsive genes, BLI-3 and BLI-4, were significantly upregulated at the DT15 stage, reaching 576.08 times and 31.30 times, respectively, while they were sharply downregulated at the DT30 stage. The KEGG enrichment analysis revealed that the DEGs were mainly involved in secondary metabolite synthesis, carbon metabolism, amino acid synthesis, redox reactions, and the MAPK signaling pathway. At the DT15 stage, genes related to growth metabolism, such as CYP, SNF1, and COX, were highly expressed, indicating active metabolism at this stage. However, in the DT0 and DT30 stages, ROS-related genes such as NADPH-dependent oxidoreductases were upregulated, leading to oxidative stress damage and inhibiting growth. Additionally, the high expression of BLI-3 and BLI-4 significantly activated ergosterol synthesis genes, enhancing cell membrane stability. The WGCNA co-expression network analysis revealed a high degree of correlation between BLI-4 and MAPKKK and CYP genes and proposed a potential “BLI-4-MAPKKK-CYP” regulatory axis, providing insights into the molecular pathway by which light regulates the metabolism and homeostasis of Poria cocos. Conclusions: This study has for the first time systematically revealed the molecular mechanism by which light duration regulates the growth activity of Poria cocos. It has clarified the core role of the BLI gene family in light signal perception and metabolic regulation. It has also elucidated the molecular pathways by which light regulates the synthesis of ergosterol, energy metabolism, and oxidative stress response in Poria cocos. This provides innovative theoretical support for optimizing the light regulation strategies in Poria cocos cultivation and also offers important references for the study of environmental response mechanisms in other medicinal fungi.

Cancer is an increasing public health burden, including in Sub-Saharan African (SSA) populations, where cancer incidence is predicted to increase by around 140% between 2022 and 2050. These rates require a better understanding of the epidemiological, clinical, and genetic/molecular characteristics of cancer in SSA populations. There is an urgent need to improve the genomic characterization of SSA tumour samples and also to establish suitable in vitro models for hypothesis testing. In fact, even though thousands of cancer cell lines (CCLs) have been established employing different methods of cell immortalization and have been included in deep molecular characterization panels, SSA ancestry is limited to only ~6% (mostly African Americans, who represent limited diversity in the context of the African continent) of publicly available CCLs. This disparity needs to be addressed by using next-generation immortalization methods such as conditional reprogramming to establish CCLs derived from SSA cancer patients that also represent the diversity within the African continent. Research in SSA oncobiology has the potential to add essential information to better understand the diverse molecular pathways leading to cancer and to find promising therapeutic avenues. We also discuss the challenges to conducting oncobiology studies with cell modelling derived from SSA patients in low-to-middle-income African countries, such as Portuguese-speaking African countries.

Agrobacterium rhizogenes (A. rhizogenes)-mediated transformation of hairy roots is a favored and flexible method for root gene functional analysis. However, the selection of transformants can be complex and time-consuming. Here, we describe our simplified method for the A. rhizogenes-mediated hairy root induction in young peanut shoots using an expression vector with RUBY for direct visual selection of transformants. Analyses verified that this method provides a high-efficiency gene transformation technique for peanut, with transformant frequencies between 46.2 and 73.7%. To test the utility of this method in gene functional analyses, it was used to overexpress AhLRX6 in hairy roots and we present our preliminary results indicating the production of thicker cells walls in root tips relative to the WT.