Cytokinin oxidase/dehydrogenases (CKXs) are the key enzymes in cytokinin degradation and have been widely studied in model plants. Little is known about apple’s (Malus×domestica) CKX genes. Here, using genome-wide analysis, we identified 10 MdCKX genes in apple. The phylogenetics, chromosome locations, and genome structures were then tested. Expression analysis showed that MdCKX genes had different expression profiles in apple, pointing to the different roles. Meanwhile, relative expression analysis showed that these genes have different expression patterns in response to several exogenous cytokinin factors, including trans-zeatin (ZT), thidiazuron (TDZ), and N6-furfuryladenine (KT). Finally, we introduced the MdCKX5.2 gene into Arabidopsis to evaluate its functions, and the results suggested the transgenic Arabidopsis displayed phenotypes related to promoting primary root and lateral root development, response to exogenous ZT, and conferring to drought and salt tolerant. Taken together, our results provide insights on the possible application of the MdCKX5.2 gene for molecular breeding in apples.
Plants mainly uptake inorganic nitrogen from soil as ammonium and nitrate. Less energy is required to assimilate ammonium compared to nitrates, and plants prefer to take up ammonium when the external nitrogen concentration is low. Investigating the patterns and mechanisms of ammonium absorption can help improve crop nitrogen utilization. In this study, we isolated MdSAT1, a gene of apple encoding an ammonium-responsive bHLH transcription factor. MdSAT1 promoted the growth and development of lateral roots and root hairs. Overexpression of MdSAT1 increased the transcript levels of genes related to ammonium uptake, indicating that MdSAT1 can regulate ammonium uptake and utilization at the transcriptional level. MdSAT1 also can modulate ROS accumulation to ultimately regulate plant growth. Taken together, these findings provide insight for us to further study the mechanisms by which MdSAT1 controls ammonium utilization as well as plant growth and development.
Inorganic phosphate (Pi) starvation severely affects the normal growth and development of plants. In this study, MdSAT1, a Pi-responsive bHLH transcription factor, was isolated from apples. Ectopic expression of MdAST1 in Arabidopsis increased the number of lateral roots and root tips, as well as the transcript levels of genes related to Pi uptake and transport; thus, improving Pi utilization in response to a Pi deficiency. Ectopic expression of MdSAT1 significantly accelerated flowering and leaf senescence in Arabidopsis under a Pi deficiency. Taken together, the present study provides a basis for an in-depth investigation of the mechanisms of MdSAT1 on apple Pi uptake and utilization as well as plant growth and development.
The study first demonstrated that burdock fructooligosaccharide (BFO) could inhibit peel browning in green banana, with 0.5% BFO treatment showing the most significant suppression of peel browning during low-temperature storage (7 ± 1 °C). The results revealed that 0.5% BFO treatment effectively restrained the increase in electrolyte leakage and malondialdehyde (MDA) content and maintained cell membrane integrity. Furthermore, BFO treatment enhanced total phenolic content and antioxidant capacity, alleviated oxidative damage, and better preserved the external quality of banana peel. Simultaneously, BFO treatment markedly inhibited both the activities of chlorophyll-degrading enzymes and their relative gene expression levels in banana peel, thereby maintaining higher chlorophyll content. This research provided a new insight into the mechanism of inhibiting peel browning for low-temperature storage preservation of banana.
Exogenous glucose functions not only as a carbon source but also as a key signaling molecule involved in regulating root development and metabolism in plants. To elucidate the molecular mechanisms underlying this response in cherry rootstock (Prunus cerasus), we performed RNA-seq on lateral roots collected at 0, 6, 12, 24, 48, and 72 h after glucose treatment. Transcriptome profiling revealed a dynamic and sustained transcriptional reprogramming, with a total of 461 differentially expressed genes (DEGs) consistently altered across all post-treatment time points relative to the control (T0). Weighted gene co-expression network analysis identified five modules strongly correlated with glucose exposure, notably enriched for genes involved in nitrogen, carbon, and sulfur metabolism. Functional enrichment analyses further revealed a pronounced overrepresentation of pathways associated with nutrient utilization, as well as carbon fixation, glycolysis, amino acid biosynthesis, and stress-responsive processes such as glutathione metabolism and MAPK signaling. Intriguingly, key transcription factors and signaling components were consistently co-enriched across multiple functional categories, suggesting the presence of a tightly coordinated regulatory network that links sugar sensing to metabolic reprogramming, redox homeostasis, and developmental plasticity. Notably, glucose treatment induced both activation and repression of nitrogen-related genes in distinct co-expression modules, indicating fine-tuned modulation of nutrient uptake in response to carbon availability. Together, these findings suggest that exogenous glucose triggers a systems-level shift in root physiology, coordinating primary metabolism with stress adaptation and growth regulation through tightly interconnected carbon–nitrogen–sulfur metabolic circuits.