Engineering wheat (Triticum aestivum L.) for abiotic resilience by manipulating small ubiquitin-like modifiers

[摘要] ENGLISH ABSTRACT: Research is becoming increasingly more focused on innovative strategies to improve wheat (Triticum aestivum L.) to meet current and future consumer demands. With the number of countries facing extreme climate variability increasing, drastic steps need to be taken to ensure local food security. Although genetic engineering of staple crops has been explored widely, they require challenging platforms with highly efficient explants with enhanced regenerative abilities for callus formation and somatic embryogenesis to consistently yield plantlets with altered attributes. Thus, this study describes the necessary steps to obtain transgenic wheat with relative ease, with the goal of improved abiotic stress tolerance. The developed in vitro regeneration and cryopreservation system was then used to introduce genes into bread wheat, namely Overly Tolerant to Salt 1 (OTS1) and OTS2 (both are Small Ubiquitin-like Modifier (SUMO) protease genes) and transcription factor known as Inducer of CBF expression 1 (ICE1). The class of molecules have emerged as an influential mechanism for targeted protein management, as SUMO proteases play a vital role in regulating pathway flux and are therefore ideal targets for manipulating stress-responsive SUMOylation. This study thus describes the isolation and cloning of three genes and its manipulation into constitutive and drought inducible vectors. The latter makes use of a unique promoter which was characterized in silico, after which it was then applied. Finally this study also demonstrated the compatibility of the vectors within wheat as it was confirmed that genetic modification of wheat was achieved by particle bombardment.

[发布机构] Stellenbosch University