Expression dynamics of phytochrome genes for the shade-avoidance response in densely direct-seeding rice

Yongtao Cui; Minhua Zhu; Jian Song; Honghuan Fan; Xiaozheng Xu; Jiayan Wu; Longbiao Guo; Jianjun Wang

doi:10.3389/fpls.2022.1105882

Expression dynamics of phytochrome genes for the shade-avoidance response in densely direct-seeding rice

Front Plant Sci. 2023 Jan 18:13:1105882. doi: 10.3389/fpls.2022.1105882. eCollection 2022.

Authors

Yongtao Cui¹, Minhua Zhu², Jian Song¹, Honghuan Fan¹, Xiaozheng Xu³, Jiayan Wu³, Longbiao Guo⁴, Jianjun Wang¹

Affiliations

¹ Institute of Crops and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
² College of Landscape and Architecture, Zhejiang A&F University, Hangzhou, China.
³ College of Advanced Agriculture Sciences, Zhejiang A&F University, Hangzhou, China.
⁴ State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.

Abstract

Because of labor shortages or resource scarcity, direct seeding is the preferred method for rice (Oryza sativa. L) cultivation, and it necessitates direct seeding at the current density. In this study, two density of direct seeding with high and normal density were selected to identify the genes involved in shade-avoidance syndrome. Phenotypic and gene expression analysis showed that densely direct seeding (DDS) causes a set of acclimation responses that either induce shade avoidance or toleration. When compared to normal direct seeding (NDS), plants cultivated by DDS exhibit constitutive shade-avoidance syndrome (SAS), in which the accompanying solar radiation drops rapidly from the middle leaf to the base leaf during flowering. Simulation of shade causes rapid reduction in phytochrome gene expression, changes in the expression of multiple miR156 or miR172 genes and photoperiod-related genes, all of which leads to early flowering and alterations in the plant architecture. Furthermore, DDS causes senescence by downregulating the expression of chloroplast synthesis-related genes throughout almost the entire stage. Our findings revealed that DDS is linked to SAS, which can be employed to breed density-tolerant rice varieties more easily and widely.

Keywords: densely direct seeding; early flowering; miR156; miR172; oryza sativa. L; phytochrome.

Grants and funding

This research was supported by Zhejiang Provincial Natural Science Foundation of China under Grant No. LQ22C130007, National Natural Science Foundation of China under Grant No. 32101791 and Key Laboratory of Digital Dry Land Crops of Zhejiang Province under Grant No.2022E10012.