Development of a marker-free engineered durum wheat overexpressing Lobularia maritima GASA1 with improved drought tolerance

• Published in: Plant physiology and biochemistry 2024-07, Vol.212, p.108775, Article 108775
• Main Authors: Ben Saad, Rania, Ben Romdhane, Walid, Bouteraa, Mohamed Taieb, Jemli, Sonia, Ben Hsouna, Anis, Hassairi, Afif
• Format: Article
• Language: English
• Subjects: Drought Resistance; Drought stress; Droughts; Gene Expression Regulation, Plant; LmGASA1; Lobularia maritima; Marker-free transgenic durum wheat; Plant Growth Regulators - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plants, Genetically Modified; Stress, Physiological - genetics; Stress-related gene; Triticum - genetics; Triticum - metabolism
• ISSN: 0981-9428; 1873-2690; 1873-2690
• DOI: 10.1016/j.plaphy.2024.108775

Due to their fixed lifestyle, plants must adapt to abiotic or biotic stresses by orchestrating various responses, including protective and growth control measures. Growth arrest is provoked upon abiotic stress and can impair plant production. Members of the plant-specific GASA (gibberellic acid-stimulated Arabidopsis) gene family play crucial roles in phytohormone responses, abiotic and biotic stresses, and plant growth. Here, we recognized and examined the LmGASA1 gene from the halophyte plant Lobularia maritima and developed marker-free engineered durum wheat plants overexpressing the gene. The LmGASA1 transcript profile revealed that it’s induced by stressful events as well as by phytohormones including GA3, MeJA, and ABA, suggesting that the LmGASA1 gene may contribute to these stress and hormone signal transduction pathways. Transient expression of GFP-LmGASA1 fusion in onion epidermal cells indicated that LmGASA1 is localized to the cell membrane. Further analysis showed that overexpression of LmGASA1 in durum wheat plants enhanced tolerance to drought stress compared with that in non-transgenic (NT) plants, imposing no yield penalty and enabling seed production even following drought stress at the vegetative stage. Altogether, our data indicate that LmGASA1 regulates both the scavenging capacity of the antioxidant enzymatic system and the activation of at least six stress-related genes that function as positive regulators of drought stress tolerance. LmGASA1 appears to be a novel gene useful for further functional analysis and potential engineering for drought stress tolerance in crops. •LmGASA1 protein promotes water deficit resilience in engineered durum wheat.•LmGASA1 protein modulates the antioxidant enzymatic system and stress-related genes expression.•The tolerance improvement potential of LmGASA1 was confirmed in a heterologous system.•LmGASA1 appears to be useful for drought stress tolerance engineering of crops.