e Tavakol - Department of Agronomy and Plant Breeding, Shiraz University
b Khahani - Department of Agronomy and Plant Breeding, Shiraz University

Rice is one of the utmost species in plant genetic science and a model plant to generalize it for broad spectrum of species. Floral transition is a critical stage of the physiological processes that thoroughly changes vegetative stage to reproductive stage. Moreover, flowering is predominantly associated with grain yield in rice and substantially affects the final grain production. Some genes such as OsGI, Hd1, Ehd1, Hd3a and RFT1 are known to regulate the main part of flowering pathways in rice. Co-expression analysis unravels group of genes simultaneously expressed under specific condition and therefore they tend to be involve in similar biological processes. Here we identified co-expressed genes including transcription factors (TFs) related to transition stage in rice using EXPath 2.0 database. Thereafter, Singular Enrichment Analysis (SEA) and pathways survey on co-expressed genes were carried out using AgriGo tools (http://bioinfo.cau.edu.cn/agriGO/) and EXPath 2.0 database, respectively. Moreover, co-expressed TF families were further studied in more details. Coexpressed genes were mainly involved in metabolic process, catalytic activity and binding. Moreover, ubiquitin and endocytosis were illustrated to have immense roles in this developmental stage and plant growth. The major TF families identified in our analysis were AP2, bZIP, GATA, Homeodomain, MADS box and WRKY that could be considered as the most important transcriptional regulators controlling flowering in cereals. These results help to uncover genetic mechanism of rice flowering.

Flowering, Ontology, Pathway, Transcription factors