Ectopic Expression of Fiber Related Gbwri1 Complements Seed Phenotype in Arabidopsis thaliana

Abstract

WRINKLED1 belongs to AP2/EREB family of transcription factors whose role has been well established in seed oil biosynthesis. The objective of the study was to trace the role of fiber related Gbwri1 in seed development and fatty acid biosynthesis. In this study, we isolated a transcript from elite fiber producing cotton (Gossypium barbadense), which is over-expressed in G. barbadense fibers as compared to G. hirsutum and G. arboreum. The putative protein encoded by this transcript exhibited homology in specific domains and protein structure with WRINKLED1 of Arabidopsis thaliana and was thus designated as Gbwri1. In this study, we investigated the functional homology of fiber elongation related Gbwri1 with fatty acid biosynthesis regulator Atwri1. Ectopic expression of Gbwri1 in wri1-3 mutant of A. thaliana was analyzed. In the transgenic lines of A. thaliana, Gbwri1 resumed the seed weight, seed area, and surface morphology to the wild type. Gbwri1 transformation rescued the wrinkled phenotype of wri1-3 mutants by resuming the expression of fatty acid biosynthesis genes biotin carboxyl carrier protein isoform 2 (bccp2) and keto-ACP synthase 1 (kas1). Moreover, the seedling development of transgenic lines on non-sucrose medium demonstrated that the Gbwri1 was able to regulate the supply of sucrose for normal seedling establishment. Our results showed that the transformation of Gbwri1 in A. thaliana wri1-3 mutant was able to complement wri1-3 impaired phenotype. Thus, Gbwri1 is involved in cotton fiber development and fatty acid biosynthesis in seeds. © 2021 Friends Science Publishers

Genome scale analysis of 1-aminocyclopropane-1-carboxylate oxidase gene family in G. barbadense and its functions in cotton fiber development

“…In our previous studies, the expression of wrinked-1, an ethylene responsive transcription factor showed highest expression in fibers of G. barbadense as compared to G. hirsutum and G. arboreum 15 . Transformation studies of Gbwri1 (EREB) in Arabidopsis thaliana have also demonstrated its role in fiber development 28 . The highest expression of this ethylene responsive transcription factor might also play a supportive tool in exploring the role of ethylene in fiber development.…”