Changes in growth, porosity, and radial oxygen loss from adventitious roots of selected mono- and dicotyledonous wetland species with contrasting types of aerenchyma
Changes in growth, porosity, and radial oxygen loss from adventitious roots of selected mono- and dicotyledonous wetland species with contrasting types of aerenchyma
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DOI：
10.1046/j.1365-3040.2000.00628.x
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发表时间：
2000-11-01
影响因子：
7.3
通讯作者：
Voesenek, LACJ
中科院分区：
文献类型：
--
作者：
Visser, EJW;Colmer, TD;Voesenek, LACJ
在停滞、缺氧的营养液中生长，使两种单子叶植物（Carex acuta 和 Juncus effusus）和三种双子叶植物（Caltha palustris、Ranunculus sceleratus 和 Rumex palustris）湿地物种的不定根孔隙率从通气条件下的 10% 至 30% 增加到 20% 至 45%。用根套氧电极测定的径向氧损失 (ROL) 的空间模式表明，这两种单子叶植物的基根区对 ROL 存在很强的本构性“屏障”。相比之下，双子叶植物的根在曝气溶液中生长时对 ROL 没有显着的“障碍”，而在停滞条件下生长时仅显示部分“障碍”。这种部分“屏障”在 C. palustris 中最强，因此与单子叶植物相比，R. sceleratus 和 R. palustris 根部基部区域的 ROL 相当大。来自基部区域的 ROL 会减少氧气向根尖的纵向扩散，从而限制这些根部进入厌氧土壤的最大穿透深度。需要对一系列基质中的大量双子叶湿地物种进行进一步研究，以阐明形成部分而不是强大的 ROL“障碍”的生态生理后果。
Growth in stagnant, oxygen-deficient nutrient solution increased porosity in adventitious roots of two monocotyledonous (Carex acuta and Juncus effusus) and three dicotyledonous species (Caltha palustris, Ranunculus sceleratus and Rumex palustris) wetland species from 10 to 30% under aerated conditions to 20-45%. The spatial patterns of radial oxygen loss (ROL), determined with root-sleeving oxygen electrodes, indicated a strong constitutive 'barrier' to ROL in the basal root zones of the two monocotyledonous species. In contrast, roots of the dicotyledonous species showed no significant 'barrier' to ROL when grown in aerated solution, and only a partial 'barrier' when grown in stagnant conditions. This partial 'barrier' was strongest in C. palustris, so that ROL from basal zones of roots of R. sceleratus and R. palustris was substantial when compared to the monocotyledonous species. ROL from the basal zones would decrease longitudinal diffusion of oxygen to the root apex, and therefore limit the maximum penetration depth of these roots into anaerobic soil. Further studies of a larger number of dicotyledonous wetland species from a range of substrates are required to elucidate the ecophysiological consequences of developing a partial, rather than a strong, 'barrier' to ROL.