Functional Diversification of euANT/PLT Genes in Oryza sativa Panicle Architecture Determination

Ai My Luong; Hélène Adam; Carole Gauron; Pablo Affortit; Fabrice Ntakirutimana; Ngan Giang Khong; Quang Hoa Le; Thi Nhu Le; Marie Fournel; Michel Lebrun; James Tregear; Stefan Jouannic

doi:10.3389/fpls.2021.692955

Functional Diversification of euANT/PLT Genes in Oryza sativa Panicle Architecture Determination

Front Plant Sci. 2021 Jul 9:12:692955. doi: 10.3389/fpls.2021.692955. eCollection 2021.

Authors

Affiliations

¹ DIADE, University of Montpellier, IRD, CIRAD, Montpellier, France.
² LMI RICE, National Key Laboratory for Plant CellBiotechnology, Agronomical Genetics Institute, University of Montpellier, IRD, CIRAD, University of Science and Technologyof Hanoi, Hanoi, Vietnam.
³ School of Biotechnology and Food Technology, Hanoi University of Science and Technology, Hanoi, Vietnam.
⁴ LSTM, University of Montpellier, IRD, CIRAD, INRAE, SupAgro, Montpellier, France.

Abstract

Grain yield, which is one of the most important traits in rice breeding, is controlled in part by panicle branching patterns. Numerous genes involved in the control of panicle architecture have been identified through mutant and QTL characterization. Previous studies suggested the importance of several AP2/ERF transcription factor-encoding genes in the control of panicle development, including the AINTEGUMENTA/PLETHORA-like (euANT/PLT) genes. The ANT gene was specifically considered to be a key regulator of shoot and floral development in Arabidopsis thaliana. However, the likely importance of paralogous euANT/PLT genes in the regulation of meristem identities and activities during panicle architecture development has not to date been fully addressed in rice. In this study, we observed that the rice euANT/PLT genes displayed divergent temporal expression patterns during the branching stages of early panicle development, with spatial localization of expression in meristems for two of these genes. Moreover, a functional analysis of rice ANT-related genes using genome editing revealed their importance in the control of panicle architecture, through the regulation of axillary meristem (AM) establishment and meristem fate transition. Our study suggests that the paralogous euANT/PLT genes have become partially diversified in their functions, with certain opposing effects, since they arose from ancestral gene duplication events, and that they act in regulating the branching of the rice panicle.

Keywords: PLETHORA; branching; meristem; panicle; rice; yield.