Poór P, Borbély P, Kovács Judit, Papp Anita, Szepesi Ágnes, Takács Z, Tari Irma
University of Szeged Department of Plant Biology Középfasor 52 H-6701 Szeged Hungary.
Acta Biol Hung. 2014 Dec;65(4):428-38. doi: 10.1556/ABiol.65.2014.4.7.
The plant hormone ethylene or the gaseous signalling molecule nitric oxide (NO) may enhance salt stress tolerance by maintaining ion homeostasis, first of all K+/Na+ ratio of tissues. Ethylene and NO accumulation increased in the root apices and suspension culture cells of tomato at sublethal salt stress caused by 100 mM NaCl, however, the induction phase of programmed cell death (PCD) was different at lethal salt concentration. The production of ethylene by root apices and the accumulation of NO in the cells of suspension culture did not increase during the initiation of PCD after 250 mM NaCl treatment. Moreover, cells in suspension culture accumulated higher amount of reactive oxygen species which, along with NO deficiency contributed to cell death induction. The absence of ethylene in the apical root segments and the absence of NO accumulation in the cell suspension resulted in similar ion disequilibrium, namely K+/Na+ ratio of 1.41 ± 0.1 and 1.68 ± 0.3 in intact plant tissues and suspension culture cells, respectively that was not tolerated by tomato.
植物激素乙烯或气态信号分子一氧化氮（NO）可通过维持离子稳态，首先是组织的K⁺/Na⁺比值，来增强盐胁迫耐受性。在由100 mM NaCl引起的亚致死盐胁迫下，番茄根尖和悬浮培养细胞中乙烯和NO的积累增加，然而，在致死盐浓度下程序性细胞死亡（PCD）的诱导阶段有所不同。在250 mM NaCl处理后PCD启动期间，根尖产生的乙烯和悬浮培养细胞中NO的积累并未增加。此外，悬浮培养细胞中积累了更高量的活性氧，这与NO缺乏一起导致了细胞死亡诱导。根尖中乙烯的缺失和细胞悬浮液中NO积累的缺失导致了类似的离子失衡，即完整植物组织和悬浮培养细胞中的K⁺/Na⁺比值分别为1.41±0.1和1.68±0.3，这是番茄无法耐受的。
