# The WD40 gene family in recretohalophyte Limonium bicolor: genomic identification and functional analysis in salt gland development and salinity tolerance

**Authors:** Lu Sun, Huiying Mu, Yuqing Tan, Baoshan Wang, Xi Wang, Fang Yuan

PMC · DOI: 10.3389/fpls.2025.1629604 · 2025-07-30

## TL;DR

This study explores salt tolerance in Limonium bicolor by analyzing WD40 genes linked to salt gland development and stress response.

## Contribution

The study identifies specific WD40 genes in Limonium bicolor involved in salt gland development and salinity tolerance.

## Key findings

- Lb1G05968 and Lb3G17197 are key WD40 genes involved in salt gland development.
- VIGS experiments showed these genes are crucial for salinity tolerance.
- Subfamily 6 is the largest WD40 gene group in L. bicolor.

## Abstract

Developing salt-tolerant crops is critical for utilizing saline soils in agriculture. Limonium bicolor, a recretohalophyte with epidermal salt glands, represents a valuable genetic resource for salt tolerance engineering. Although WD40 proteins are known regulators of plant stress responses, their roles in L. bicolor remain unexplored.

We performed a genome-wide analysis of WD40 genes in L. bicolor, including phylogenetic classification, subcellular localization prediction, cis-element analysis, and expression profiling during salt stress. Functional validation was conducted using virus-induced gene silencing (VIGS).

Among 367 identified WD40 genes (distributed across all chromosomes), Subfamily 6 was the largest. Two key members (Lb1G05968 and Lb3G17197, localized in cytoplasm) showed significant involvement in salt gland development and stress tolerance, as demonstrated by VIGS-induced phenotypic defects.

Our findings reveal the WD40 family's expansion in L. bicolor and its functional specialization in salt adaptation. The identified genes (e.g., Lb1G05968, Lb3G17197) provide targets for engineering salt-tolerant crops. This study establishes a foundation for further research on halophyte developmental genetics.

## Linked entities

- **Genes:** thul16 (thyroid hormone up-regulated protein (gene 16)) [NCBI Gene 496862]
- **Proteins:** thul16 (thyroid hormone up-regulated protein (gene 16))
- **Species:** Limonium bicolor (taxon 293754), Mus musculus (taxon 10090)

## Full-text entities

- **Genes:** AT2G47790 (Transducin/WD40 repeat-like superfamily protein) [NCBI Gene 819391] {aka F17A22.18, GIGANTUS 1, GTS1}, PRL1 (pleiotropic regulatory locus 1) [NCBI Gene 827272] {aka DL3990W, FCAALL.40, PRL1 PROTEIN, pleiotropic regulatory locus 1}, GL3 (basic helix-loop-helix (bHLH) DNA-binding superfamily protein) [NCBI Gene 834133] {aka GLABRA 3, GLABROUS 3, MYC6.2}, TTG1 (Transducin/WD40 repeat-like superfamily protein) [NCBI Gene 832523] {aka ATTTG1, K18P6.4, K18P6_4, TRANSPARENT TESTA GLABRA 1, TTG, UNARMED 23}, MYB0 (myb domain protein 0) [NCBI Gene 822415] {aka ATGL1, ATMYB0, GL1, GLABRA 1, TRICHOME DIFFERENTIATION PROTEIN GL1, myb domain protein 0}, HSP70 (heat shock protein 70) [NCBI Gene 820438] {aka ARABIDOPSIS HEAT SHOCK PROTEIN 70, ATHSP70, heat shock protein 70}
- **Chemicals:** Murashige (-), acetic acid (MESH:D019342), NBT (MESH:D009580), Leu (MESH:D007930), kanamycin (MESH:D007612), sugar (MESH:D000073893), ROS (MESH:D017382), MgCl2 (MESH:D015636), FM4-64 (MESH:C092350), His (MESH:D006639), ethanol (MESH:D000431), water (MESH:D014867), anthocyanin (MESH:D000872), agar (MESH:D000362), chlorophyll (MESH:D002734), Ade (MESH:C060154), MES (MESH:C004550), sodium hypochlorite (MESH:D012973), Trp (MESH:D014364), acetosyringone (MESH:C051667), Salt (MESH:D012492), mineral oil (MESH:D008899), 4',6-diamidino-2-phenylindole (MESH:C007293), ABA (MESH:D000040), nitrogen (MESH:D009584), NaCl (MESH:D012965), rifampicin (MESH:D012293), Na+ (MESH:D012964)
- **Species:** Saccharomyces cerevisiae (baker's yeast, species) [taxon 4932], Glycine max (soybean, species) [taxon 3847], Agrobacterium tumefaciens (species) [taxon 358], Prunus persica (peach, species) [taxon 3760], Solanum lycopersicum (tomato, species) [taxon 4081], Limonium bicolor (species) [taxon 293754], Setaria italica (foxtail millet, species) [taxon 4555], Chenopodium quinoa (quinoa, species) [taxon 63459], Arabidopsis thaliana (mouse-ear cress, species) [taxon 3702], Chlamydomonas reinhardtii (species) [taxon 3055], Homo sapiens (human, species) [taxon 9606], Cucumis sativus (cucumber, species) [taxon 3659], Beta vulgaris subsp. vulgaris (field beet, subspecies) [taxon 3555], Nicotiana benthamiana (species) [taxon 4100], Oryza sativa (Asian cultivated rice, species) [taxon 4530], Fagopyrum tataricum (Kangra buckwheat, species) [taxon 62330], Beta vulgaris (beet, species) [taxon 161934], L. bicolor [taxon 187797], Diospyros virginiana (American persimmon, species) [taxon 13493]
- **Mutations:** tryptophan-aspartic acid

## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12343514/full.md

---
Source: https://tomesphere.com/paper/PMC12343514