Transcriptome analysis of flowering regulation by sowing date in Japonica Rice (Oryza sativa L.)

Min Yin,Chunmei Xu,Hengyu Ma,Mengjia Wang,Xiufu Zhang,Guang Chu,Song Chen,Yuanhui Liu,Danying Wang

doi:10.1038/s41598-021-94552-3

Abstract

Hybrid japonica cultivars, such as the Yongyou series, have shown high yield potential in the field in both the early and late growing seasons. Moreover, understanding the responses of rice flowering dates to temperature and light is critical for improving yield performance. However, few studies have analyzed flowering genes in high-yielding japonica cultivars. Based on the five sowing date experiments from 2019 to 2020, select the sensitive cultivar Yongyou 538 and the insensitive cultivar Ninggeng 4 and take their flag leaves and panicles for transcriptome analysis. The results showed that compared with sowing date 1 (6/16), after the sowing date was postponed (sowing date 5, 7/9), 4480 and 890 differentially expressed genes (DEGs) were detected in the leaves and panicles in Ninggeng 4, 9275 and 2475 DEGs were detected in the leaves and panicles in Yongyou 538, respectively. KEGG pathway analysis showed that both Ninggeng 4 and Yongyou 538 regulated rice flowering through the plant circadian rhythm and plant hormone signal transduction pathways. Gene expression analysis showed that Os01g0566050 (OsELF3-2), Os01g0182600 (OsGI), Os11g0547000 (OsFKF1), Os06g0275000 (Hd1), and Os09g0513500 (FT-1) were expressed higher and Os02g0771100 (COP1-1) was expressed lower in Yongyou 538 compared with Ninggeng 4 as the climate conditions changed, which may be the key genes that regulate the flowering process with the change of temperature and light resources in sensitive cultivar Yongyou 538 in the late season.

Highlights

Hybrid japonica cultivars, such as the Yongyou series, have shown high yield potential in the field in both the early and late growing seasons
Many of the genes involved in the photoperiod pathway in rice flowering have been successfully cloned by QTL mapping methods, such as Heading date 1 (Hd1), Heading date-3a (Hd3a), Early heading date 1 (Ehd1), Rice Indeterminate 1 (RID1), etc
Map-based cloning has revealed that the rice photoperiod pathway is regulated mainly by two independent signal pathways, the OsGI-Hd1-Hd3a pathway[7], which is conserved with Arabidopsis, and unique genes such as Ehd[116], Ehd[217], Ehd[318], Ghd[719], etc

Summary

Introduction

Hybrid japonica cultivars, such as the Yongyou series, have shown high yield potential in the field in both the early and late growing seasons. Gene expression analysis showed that Os01g0566050 (OsELF3-2), Os01g0182600 (OsGI), Os11g0547000 (OsFKF1), Os06g0275000 (Hd1), and Os09g0513500 (FT-1) were expressed higher and Os02g0771100 (COP1-1) was expressed lower in Yongyou 538 compared with Ninggeng 4 as the climate conditions changed, which may be the key genes that regulate the flowering process with the change of temperature and light resources in sensitive cultivar Yongyou 538 in the late season. Analyzing the climate adaptability of japonica rice is of great significance for breeding and selecting japonica varieties with wide adaptability and high quality and yield. The main objectives of this study were to (1) analyze japonica flowering adaptation in response to climate conditions change and (2) select the key genes regulating flowering adaptability to facilitate the spread of japonica rice to a wider planting area

Objectives

Methods

Results

Discussion

Conclusion