Growth-related changes in salt gland mass in gentoo and chinstrap penguin chicks

Abstract Background Identifying 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. Results The 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. Conclusion These results indicate that LbHLH enhances salt tolerance by reducing root hair development and enhancing osmotic resistance under NaCl stress.

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The Na-K-Cl cotransporter of avian salt gland. Phosphorylation in response to cAMP-dependent and calcium-dependent secretogogues.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)74061-7 ◽

1992 ◽

Vol 267 (35) ◽

pp. 25444-25450 ◽

Cited By ~ 1

Author(s):

J Torchia ◽

C Lytle ◽

D.J. Pon ◽

B Forbush ◽

A.K. Sen

Keyword(s):

Salt Gland ◽

Calcium Dependent

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Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

Scientific Reports ◽

10.1038/s41598-021-93974-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaojing Xu ◽

Yingli Zhou ◽

Ping Mi ◽

Baoshan Wang ◽

Fang Yuan

Keyword(s):

Salt Tolerance ◽

Photosynthetic Rate ◽

Large Scale ◽

Soluble Sugars ◽

Dry Weight ◽

Salt Gland ◽

Salt Glands ◽

Chlorophyll Contents ◽

Relative Water ◽

Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

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