Vacuolar acidity, protein profile, and crystal composition of epidermal bladder cells of the halophyte Mesembryanthemum crystallinum
Vacuolar acidity, protein profile, and crystal composition of epidermal bladder cells of the halophyte Mesembryanthemum crystallinum
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DOI：
10.1071/fp06269
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发表时间：
2007-01-01
影响因子：
3
通讯作者：
Yen, Hungchen Emilie
中科院分区：
文献类型：
--
作者：
Jou, Yingtzy;Wang, Ya-Ling;Yen, Hungchen Emilie
盐生植物中胚草（Mesembryocarcinum crytallinum L.）(ice植物）的标志是巨大的表皮膀胱细胞（EBC）。铺面细胞分化为EBC发生在早期发育阶段。EBC占据了盐胁迫成熟冰草地上部分的大部分表面积。一个大的液泡水库的离子和水的储存起着重要的作用，在盐度适应。为了监测EBC不同发育阶段液泡的酸度，用pH敏感染料中性红（NR）对远轴面果皮进行染色。在冰草幼叶期，存在NR染色（酸性）和NR未染色（中性）的EBC。连续暴露于光照降低了NR染色细胞的酸度。EBC蛋白质谱说明了这些特化细胞中高度酸性和碱性蛋白质的显著共存。在EBC中积累的主要蛋白质参与光合作用、钠区室化和防御。在施肥良好的冰植物中发现了大量的针晶。盐胁迫细胞表现出的变化，在表面电荷和元素组成的针晶。钾在高盐生长的晶体中的消失表明，这些晶体可能作为钾的水库，以维持Na+K+在这种盐生植物的稳态。
The halophyte Mesembryanthemum crytallinum L. (ice plant) is marked by giant epidermal bladder cells (EBC). The differentiation of pavement cells into EBC occurs at an early developmental stage. EBC occupy most of the surface area in the aerial parts of salt-stressed mature ice plants. A large vacuolar reservoir for ion and water storage plays an important role in salinity adaptation. To monitor the acidity of the vacuole at different developmental stages of EBC, peels from the abaxial surface were stained with a pH-sensitive dye, neutral red (NR). Presence of both NR-stained (acidic) and NR-unstained (neutral) EBC were found at the juvenile stage in ice plants. Continuous exposure to illumination decreased the acidity of the NR-stained cells. The EBC protein profile illustrated the prominent co-existence of highly acidic and basic proteins in these specialised cells. Major proteins that accumulate in EBC are involved in photosynthesis, sodium compartmentalisation, and defence. Numerous raphide crystals were found in well fertilised ice plants. Salt-stressed cells exhibited changes in the surface charge and element composition of raphide crystals. A disappearance of potassium in the high-salt grown crystals suggests that these crystals might serve as a potassium reservoir to maintain the Na+K+ homeostasis in this halophyte.