Abstract
BackgroundIdentifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance. Here we cloned the previously uncharacterized gene LbHLH and explored its role in salt tolerance.ResultsThe 2,067-bp open reading frame of LbHLH encodes a 688-amino-acid protein with a typical helix-loop-helix (HLH) domain. In situ hybridization showed that LbHLH is expressed in salt glands of L. bicolor. LbHLH localizes to the nucleus, and LbHLH is highly expressed during salt gland development and in response to NaCl treatment. To further explore its function, we heterologously expressed LbHLH in Arabidopsis thaliana under the 35S promoter. The overexpression lines showed significantly increased trichome number and reduced root hair number. LbHLH might interact with GLABRA1 to influence trichome and root hair development, as revealed by yeast two-hybrid analysis. The transgenic lines showed higher germination percentages and longer roots than the wild type under NaCl treatment. Analysis of seedlings grown on medium containing sorbitol with the same osmotic pressure as 100 mM NaCl demonstrated that overexpressing LbHLH enhanced osmotic resistance.ConclusionThese results indicate that LbHLH enhances salt tolerance by reducing root hair development and enhancing osmotic resistance under NaCl stress.
Highlights
Identifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance
We investigated the role of Lb1G04899, a gene of unknown function that is highly expressed in L. bicolor during early salt gland development, as determined by transcriptome analysis [19]
No self-activation of LbHLH was detected. These results indicate that LbHLH strongly interacts with AtGL1, an MYB-like protein required for root hair development, which could explain why root hair formation was significantly inhibited in the transgenic lines
Summary
Identifying genes involved in salt tolerance in the recretohalophyte Limonium bicolor could facilitate the breeding of crops with enhanced salt tolerance. According to the Food and Agriculture Organization of the United Nations (FAO), soil salinity affects 950 million hectares of land worldwide, accounting for more than 6.5% of the world’s total land area [1, 2]. Wang et al BMC Plant Biol (2021) 21:284 pseudohalophytes (salt-repellent halophytes), such as Phragmites communis, block salt from entering cells [11]; and (3) recretohalophytes, such as Limonium bicolor and Mesembryanthemum crystallinum, secrete salt to the outside environment [12]. Recretohalophytes have specialized structures, including salt bladders and salt glands [13], that collect or secrete salt out of the plant to avoid salt stress [14]. Whereas salt glands actively excrete excess salt out of the plant [15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
