A multilayered cross-species analysis of GRAS transcription factors uncovered their functional networks in plant adaptation to the environment

Abstract

Introduction: Environmental stress is both a major force of natural selection and a prime factor affecting crop qualities and yields. The impact of the GRAS [gibberellic acid-insensitive (GAI), repressor of GA1-3 mutant (RGA), and scarecrow (SCR)] family on plant development and the potential to resist environmental stress needs much emphasis.

Objectives: This study aims to investigate the evolution, expansion, and adaptive mechanisms of GRASs of important representative plants during polyploidization.

Methods: We explored the evolutionary characteristics of GRASs in 15 representative plant species by systematic biological analysis of the genome, transcriptome, metabolite, protein complex map and phenotype.

Results: The GRAS family was systematically identified from 15 representative plant species of scientific and agricultural importance. The detection of gene duplication types of GRASs in all species showed that the widespread expansion of GRASs in these species was mainly contributed by polyploidization events. Evolutionary analysis reveals that most species experience independent genome-wide duplication (WGD) events and that interspecies GRAS functions may be broadly conserved. Polyploidy-related Chenopodium quinoa GRASs (CqGRASs) and Arabidopsis thaliana GRASs (AtGRASs) formed robust networks with flavonoid pathways by crosstalk with auxin and photosynthetic pathways. Furthermore, Arabidopsis thaliana population transcriptomes and the 1000 Plants (OneKP) project confirmed that GRASs are components of flavonoid biosynthesis, which enables plants to adapt to the environment by promoting flavonoid accumulation. More importantly, the GRASs of important species that may potentially improve important agronomic traits were mapped through TAIR and RARGE-II publicly available phenotypic data. Determining protein interactions and target genes contributes to determining GRAS functions.

Conclusion: The results of this study suggest that polyploidy-related GRASs in multiple species may be a target for improving plant growth, development, and environmental adaptation.

Keywords: Environmental stress; GRAS; Plant population; Polyploidization; Systems biology.