K+ accumulation in the cytoplasm and nucleus of the salt gland cells of Limonium bicolor accompanies increased rates of salt secretion under NaCl treatment using NanoSIMS. (September 2015)

• Record Type: Journal Article
• Authors: Feng, Zhong-Tao; Deng, Yun-Quan; Zhang, Shi-Chao; Liang, Xue; Yuan, Fang; Hao, Jia-Long; Zhang, Jian-Chao; Sun, Shu-Feng; Wang, Bao-Shan
• Is Part Of: Plant science. Volume 238(2015:Sep.)
• Page Start: 286
• Page End: 296
• Publication Date: 2015-09
• Subjects: DAPI 4′, 6-diamidino-2-phenylindole -- DM dry mass -- FS freeze substitution -- HPF high-pressure freezing -- LSCM laser scanning confocal microscope -- MRP mass resolving power -- NMT non-invasive micro-test technology -- PPFD photosynthetic photon flux density -- SE secondary electron -- SEM scanning electron microscope -- SIMS secondary ion mass spectrometry -- TEM transmission electron microscope; Elemental localization -- Limonium bicolor -- NanoSIMS -- NMT -- Salt gland -- Ultrastructure; Botany -- Periodicals; Botanique -- Périodiques; 580
• DOI: 10.1016/j.plantsci.2015.06.021
• Languages: English
• ISSNs: 0168-9452

Abstract

Highlights: There are 16 cells in the salt gland of L. bicolor, including four secretory cells. NaCl treatment enhanced K + accumulation in cytoplasm and nucleus of salt gland cells. Higher signal strength of Na + was located in the apoplast of salt gland cells. NaCl treatment markedly increased Na + secretion rate but decreased K + secretion rate. Abstract: Recretohalophytes with specialized salt-secreting structures (salt glands) can secrete excess salts from plant, while discriminating between Na + and K + . K + /Na + ratio plays an important role in plant salt tolerance, but the distribution and role of K + in the salt gland cells is poorly understood. In this article, the in situ subcellular localization of K and Na in the salt gland of the recretohalophyte Limonium bicolor Kuntze is described. Samples were prepared by high-pressure freezing (HPF), freeze substitution (FS) and analyzed using NanoSIMS. The salt gland of L. bicolor consists of sixteen cells. Higher signal strength of Na + was located in the apoplast of salt gland cells. Compared with control, 200 mM NaCl treatment led to higher signal strength of K + and Na + in both cytoplasm and nucleus of salt gland cells although K + /Na + ratio in both cytoplasm and nucleus were slightly reduced by NaCl. Moreover, the rate of Na + secretion per salt gland of L. bicolor treated with 200 mM NaCl was five times that of controls. These results suggest that K + accumulation both in the cytoplasm and nucleus of salt gland cells under salinity may play an important role in salt secretion, although the exact mechanism is unknown.