Study on pathway and characteristics of ion secretion of salt glands of Limonium bicolor

Abstract

Recretohalophytes with specialized salt-secreting structures, including salt glands and salt bladders, can secrete excess salts from plant tissues and enhance salinity tolerance of plants. However, the pathway and property of salt secretion by the salt gland has not been elucidated. In the article, Limonium bicolor Kuntze was used to investigate the pathway and characteristics of salt secretion of salt gland. Scanning electron microscope micrographs showed that each of the secretory cells had a pore in the center of the cuticle, and the rice grain-like secretions were observed above the pore. The chemical composition of secretions from secretory pores was mainly NaCl using environmental scanning electron microscope technique. Non-invasive micro-test technology was used to directly measure ion secretion rate of salt gland, and secretion rates of Na ? and Cl -were greatly enhanced by a 200-mmol/L NaCl treatment. However, epidermal cells and stoma showed little secretion of ions. In conclusion, our results provide evidence that the salt glands of L. bicolor have four secretory pores and that NaCl is secreted through these pores of salt gland.

Molecular mechanisms underlying stress response and adaptation

“…The salt gland is the first differentiated epidermal structure in Limonium bicolor, differentiating two days earlier than the stomata . These salt glands have four secretory pores in the center of the cuticle that secrete NaCl . Using high‐throughput RNA sequencing, candidate genes have been identified in the Limonium bicolor salt gland that are highly associated with salt secretion .…”

“…[98][99][100] These salt glands have four secretory pores in the center of the cuticle that secrete NaCl. 32 Using highthroughput RNA sequencing, candidate genes have been identified in the Limonium bicolor salt gland that are highly associated with salt secretion. 29,101 In addition, an efficient method has been developed to screen for mutants capable of adapting to abnormal salt gland density.…”

“…These stresses can affect nutrient uptake and utilization; therefore, plants have developed a wide variety of structural, morphological, and regulatory adaptations to address these environmental stresses . In particular, multi‐level regulatory mechanisms involved in salt tolerance have been well characterized in halophytes, such as Suaeda salsa, Thellungiella salsuginea , and Limonium bicolor . Adaptations to cold stress, drought, and UV radiation have also been reported to a lesser degree.…”

“…3,[21][22][23] In particular, multi-level regulatory mechanisms involved in salt tolerance have been well characterized in halophytes, such as Suaeda salsa, 5,[24][25][26] Thellungiella salsuginea, 27,28 and Limonium bicolor. [29][30][31][32][33] Adaptations to cold stress, drought, and UV radiation have also been reported to a lesser degree.…”

Therapeutic targeting of cellular stress responses in cancer

“…All living things experience adverse conditions at some point during their lifespan. [1][2][3][4][5] Plants and animals are subjected to abiotic and biotic stresses that include salt, [6][7][8][9][10][11] drought, [12][13][14][15] and pathogens. [16][17][18][19][20] Environmental stresses also affect organisms at the cellular level.…”