Allelic variation in rice Fertilization Independent Endosperm 1 contributes to grain width under high night temperature stress

Authors

Balpreet K. Dhatt, University of Nebraska-LincolnFollow
Puneet Paul, University of Nebraska-LincolnFollow
Jaspreet Sandhu, University of Nebraska - LincolnFollow
Waseem Hussain, University of Nebraska - LincolnFollow
Larissa Irvin, University of Nebraska-LincolnFollow
Feiyu Zhu, University of Nebraska - LincolnFollow
Maria Arlene Adviento-Borbe, USDA-ARS, Jonesboro, ARFollow
Argelia Lorence, Arkansas State University - Main CampusFollow
Paul Staswick, University of Nebraska-LincolnFollow
Hongfeng Yu, University of Nebraska - LincolnFollow
Gota Morota, Virginia Polytechnic Institute and State University, BlacksburgFollow
Harkamal Walia, University of Nebraska-LincolnFollow

ORCID IDs

Balpreet K. Dhatt https://orcid.org/0000-0002-3577-962X

Puneet Paul https://orcid.org/0000-0001-8220-8021

Jaspreet Sandhu https://orcid.org/0000-0001-7863-2532

Waseem Hussain https://orcid.org/0000-0002-6861-0193

Argelia Lorence https://orcid.org/0000-0001-9844-8820

Paul Staswick https://orcid.org/0000-0003-2798-0275

Gota Morota https://orcid.org/0000-0002-3567-6911

Harkamal Walia https://orcid.org/0000-0002-9712-5824

Date of this Version

2020

Citation

New Phytologist (2021) 229: 335–350

doi: 10.1111/nph.16897

Comments

(c) 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License,

Abstract

A higher minimum (night-time) temperature is considered a greater limiting factor for reduced rice yield than a similar increase in maximum (daytime) temperature. While the physiological impact of high night temperature (HNT) has been studied, the genetic and molecular basis of HNT stress response remains unexplored.

We examined the phenotypic variation for mature grain size (length and width) in a diverse set of rice accessions under HNT stress. Genome-wide association analysis identified several HNT-specific loci regulating grain size as well as loci that are common for optimal and HNT stress conditions.

A novel locus contributing to grain width under HNT conditions colocalized with Fie1, a component of the FIS-PRC2 complex. Our results suggest that the allelic difference controlling grain width under HNT is a result of differential transcript-level response of Fie1 in grains developing under HNT stress.

We present evidence to support the role of Fie1 in grain size regulation by testing overexpression (OE) and knockout mutants under heat stress. The OE mutants were either unaltered or had a positive impact on mature grain size under HNT, while the knockouts exhibited significant grain size reduction under these conditions.