Effect Of Lentinan On Growth And Gene Expression Of Plant Root

Lentinan is one of the commom fungal polysaccharides, which presents broad bioactivities such as antibacterial, anticancer. Glycyrrhiza uralensis is a plant common in the medicinal plants with glycyrrhizic acid as the main physiological component, which has extensively anti-inflammatory and antibacterial avtivities. We found that the lentinan promote the length and weight of Glycyrrhiza uralensis roots observably. In order to explore the species range and the molecular mechanism of the promotion to roots, the lentinan was get from hypha fermentation, sprayed to Glycyrrhiza uralensis, Brassica campestris L. and Achyranthis bidentatae B.. In addition, we made a transcriptome sequencing data bank of Glycyrrhiza uralensis by Illumina HiSeq 2500 platform. The main results are as follows.We get 0.384 g/100 mL and 0.218 g/100 mL as the largest concentration of biomass of mycelium and exopolysaccharides (EPS) respectively. After the purifying, we get the percent conversion as 13.3% and 45.5% for the neutral and acidic polysaccharoses.Spraying lentinan solution to the three species in a month, the length of Brassica Campestris L. roots and the ratio of root and stem increased significantly(p<0.05) with the best concentration at 0.05×10-6 g/mL, however the dry weight has no significant changes. The length of roots and ratio of root and stem of Achyranthis Bidentatae B. increased and the best level was 0.5 X 10-6 g/mL while the dry weight had no significant differences. The length and dry weight of G. Uralensis roots and the ratio of root and stem has a significant increase (p<0.05), and the best concentration was 5×10-6 g/mL. So the low concentration of lentinan could significantly promote the elongation of roots, while the best concentration is different between species.The results of flow cytometry suggested that the length of the gene sequence of G. Uralensis is 420±34.79 Mbp. A 2 G data from the transcription sequencing of G. Uralensis root was gained, and 57535 transcrip,52908 Unigene were generated through the de novo assembler software. The differentially expressed genes join 283 metabolic pathways, majority of which are terpenoid biosynthesis, plant hormone signal transduction, ribosome biosynthesis and protein biosynthesis.In conclusion, Lentinan promote the elongation of root cells by motivating auxin receptors, enhancing genes’ expression of the key enzymes in hormone signal transduction and adjusting the metabolic pathways due to the environmental adaptation. At the standard of μg, the bioactivity of lentinan to plants is similar to plant hormons which presents a promising application in agriculture. To verify the lentinan as a new root growth promoting agent, we need further studies.