JIA-2018-09

1941 HAN Jiao et al. Journal of Integrative Agriculture 2018, 17(9): 1932–1945 receptor protein serine/threonine kinase signaling pathway, and dephosphorylation 5´-nucleotidase activity. 3.5. GO functional enrichment analysis on differen- tially expressed genes Functional enrichment analyses of differentially expressed genes were performed by the Gene Ontology Database and the Japan Genome Annotation Database. The results showed that total 198 DEGs between the transgenic lines and the wild type were functionally annotated, and total 30 Go Terms of DEGs were involved in the biological functions. In detail, these DEGs were separately enriched by 17 Go Terms involved in molecular function (MF), 10 Go Terms involved in biological process (BP), and three Go Terms involved in cellular component (CC) (Fig. 8-A). The up- regulated genes participating in the molecular function mainly are gathered in the most enriched terms like peptide receptor activity, transmembrane receptor protein serine/ threonine kinase activity ubiquitin ligase binding protein, ubiquitin protein ligase binding, and transmembrane receptor protein serine/threonine kinase activity. The down-regulated genes were enriched by calcium ion binding and O-methyltransferase activity (Fig. 8-B). The genes involved in the biological process were mainly enriched by transmembrane receptor protein serine/threonine kinase signaling pathway, hormone-mediated signaling pathway, and protein autophosphorylation. Most of the up-regulated genes were represented by the hormone-mediated signaling pathway, protein autophosphorylation, and transmembrane receptor protein serine/hreonine kinase signaling pathway. In the cellular component, the cytoplasmic membrane-bounded vesicle demonstrated the highest enrichments of DEGs, and followed by plasmodesma and plasma membrane. Most of the up-regulated genes were represented by the cytoplasmic membrane-bounded vesicle, and most of the down-regulated genes were represented by the clusters of the mitochondrion and cytoplasmic membrane-bounded vesicle. 3.6. Pathway enrichment analyses of differentially expressed genes To further understand the enrichment profiles of differentially expressed genes involved in metabolic pathways, the differentially expressed genes were compared against the KEGG database by pathway enrichment analysis. The enrichments of 30 pathway terms were selected to statistically determine the DEGs number of up- or down- regulation in each pathway term (Fig. 9). The largest cluster of up-regulated genes was revealed by plant-pathogen interaction, and the number of the down-regulated genes was lower than the number of the up-regulated genes. Data showed that these metabolic pathways are mainly involved in the plant secondary metabolic pathways such as phenylpropanoid synthesis, phenylalanine metabolism, and the secondary metabolite synthesis. 4. Discussion 4.1. McPht gene is induced by Pi deficiency and participates in the growth regulation of the roots Homology alignment showed that the McPht gene from M. crystallinum demonstrates a typical structure of the Pht3 subfamily members containing six transmembrane domains, and is a homolog of the mitochondrial phosphate transporters, which have been confirmed to be located in the mitochondria of plant cells (Stappen and Kramer 1994). Studies have shown that phosphate transporters play a positive role in plant growth under environmental stress (Ai et al . 2009; Li et al . 2015). Our data showed an Table 2 A partial descriptions of the differentially expressed genes (DEGs) Gene ID Accession no. Log 2 Fold p-value q-value Diff 1) Function annotation Os02g0602300 XM_015770452.1 2.25 8.27E-98 5.49E-94 Up Regulation of catalytic activity, regulation of cellular process Os07g0650600 XM_015791412.1 1.20 8.37E-47 2.08E-43 Up Uncharacterized protein LOC4344126 Os02g0106100 XM_015770302.1 1.71 3.07E-16 2.35E-13 Up Carbohydrate metabolic process, sucrose 1-fructosyltransferase Os10g0190800 XM_015757506.1 1.15 9.48E-13 4.72E-10 Up Oxidoreductase activity, acting on NAD(P)H, nitrogenous group as acceptor Os04g0650700 XM_015779964.1 1.46 4.24E-11 1.56E-08 Up Isoaspartyl peptidase/L-asparaginase 2 Os09g0355400 XM_015757124.1 1.13 2.92E-09 7.97E-07 Up Threonine-protein kinase, transmembrane receptor protein serine/threonine kinase signaling pathway Os08g0157500 XM_015794567.1 1.10 4.43E-09 1.13E-06 Up Flavone 3´-O-methyltransferase 1, response to salicylic acid Os03g0348200 XM_015773274.1 1.19 2.71E-06 0.000299 Up Alpha-humulene synthase, magnesium ion binding Os06g0266800 XM_015786238.1 –2.92 9.99E-12 3.98E-09 Down Gibberellin-regulated protein 5, response to salicylic acid Os12g0180600 XM_015765071.1 –2.63 3.09E-07 4.97E-05 Down Dephosphorylation, 5´-nucleotidase activity 1) Diff, difference.