Characterization of a Novel TtLEA2 Gene From Tritipyrum and Its Transformation in Wheat to Enhance Salt Tolerance

Late embryogenesis-abundant (LEA) proteins are critical in helping plants cope with salt stress. Y1805 is a salt-tolerant Tritipyrum. We identified a Y1805-specific LEA gene that was expressed highly and sensitively under salt stress using transcriptome analysis. The novel group 2 LEA gene (TtLEA2-1) was cloned from Y1805. TtLEA2-1 contained a 453 bp open reading frame encoding an 151-amino-acid protein that showed maximum sequence identity (77.00%) with Thinopyrum elongatum by phylogenetic analysis. It was mainly found to be expressed highly in the roots by qRT-PCR analysis and was located in the whole cell. Forty-eight candidate proteins believed to interact with TtLEA2-1 were confirmed by yeast two-hybrid analysis. These interacting proteins were mainly enriched in environmental information processing, glycan biosynthesis and metabolism, and carbohydrate metabolism. Protein-protein interaction analysis indicated that the translation-related 40S ribosomal protein SA was the central node. An efficient wheat transformation system has been established. A coleoptile length of 2 cm, an Agrobacteria cell density of 0.55-0.60 OD600, and 15 KPa vacuum pressure were ideal for common wheat transformation, with an efficiency of up to 43.15%. Overexpression of TaLEA2-1 in wheat 1718 led to greater height, stronger roots, and higher catalase activity than in wild type seedlings. TaLEA2-1 conferred enhanced salt tolerance in transgenic wheat and may be a valuable gene for genetic modification in crops.

Automated summary

The Y1805-specific LEA gene, TtLEA2-1, was identified and found to be highly and sensitively expressed under salt stress. It showed sequence identity with Thinopyrum elongatum and was mainly expressed in the roots. Interaction analysis revealed 48 candidate proteins that interact with TtLEA2-1, mainly involved in environmental information processing and metabolism. Overexpression of TaLEA2-1 in wheat increased salt tolerance.