The wheat lipid transfer protein (TdLTP2) mitigates biotic and abiotic stress damages in transgenic Arabidopsis thaliana plants

Abstract

Lipid transfer proteins (LTPs) are members of the pathogenesis-related protein family 14 (PR-14), believed to play a role in plant defense responses. This study reports the overexpression of TdLTP2, a family 2 LTP from durum wheat, in Arabidopsis thaliana. Transgenic Arabidopsis plants with increased TdLTP2 expression unveiled greater tolerance to salt, abscisic acid (ABA), and salicylic acid (SA) stresses, as well as higher tolerance to oxidative stress when compared to wild type (Wt) plants. The transgenic plants also exhibited significant increases in the accumulation of antioxidant enzymes, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), along with decreased levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2). RT-qPCR analysis of the antioxidant enzymes confirm the role played by TdLTP2 in regulating oxidative stress under salt (100 mM NaCl) and oxidative (3 mM H2O2) stresses. Moreover, detached leaves from transgenic Arabidopsis lines expressing the TdLTP2 gene displayed enhanced resistance against fungal pathogens such as Aspergillus niger, Fusarium graminarium, Botrytis cinerea, and Alternaria solani. Finally, RT-qPCR results for biotic stress-related genes (PR1, PDF1.2, LOX3, and VSP2) showed differential expression in transgenic TdLTP2 lines when plants were treated with jasmonic acid (JA). Collectively, these findings provide evidence for the involvement of TdLTP2 gene in enhancing tolerance to both abiotic and biotic stresses in crop plants.