Rhizosphere O2 dynamics in young Zostera marina and Ruppia maritima
Rhizosphere O2 dynamics in young Zostera marina and Ruppia maritima
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DOI：
10.3354/meps11041
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发表时间：
2015-01-07
影响因子：
2.5
通讯作者：
Glud, Ronnie N.
中科院分区：
文献类型：
--
作者：
Jovanovic, Zeljko;Pedersen, Mia O.;Glud, Ronnie N.
大叶藻和川蔓藻经常共享同一生境，但R.海洋生物似乎对环境压力有更强的抵抗力。我们研究了光照强度和水柱O-2浓度对Z幼标本径向氧损失（ROL）的影响。marina和R. maritima平面光极成像显示Z. marina定位于根尖，而R. maritima表现出ROL沿着广泛的根部分。两种植物的根系总生物量相近，但R. maritima只有1条根，其中ROL、Z. marina有2 ~ 5个单独的根，其中只有2 ~ 3个表现出O-2渗漏，但仅在根尖。ROL导致Z的好氧体积为4.26 +/- 0.51 mm（3）植物（-1）。marina和5.39 ± 0.47 mm（3）株（-1）; maritima（n = 3）。在光饱和条件下，玉米的每株ROL分别为2.32 +/- 0.30和2.89 +/- 0.38 nmol h（-1）。marina和R.分别是maritima。在黑暗中，这些值分别下降了71%和60%。然而，只要环境O-2水平保持>50%的空气饱和度，两种物种都能够保持ROL。在24小时循环中，计算的ROL为48.8 +/- 10.6 nmol O-2 plant（-1）d（-1）（n = 3）。maritima和Z.码头R. maritima保持比Z更高的ROL。滨海可能是一个重要的功能，确定其在富营养化沉积物中的殖民和维持增长的潜力。
Zostera marina and Ruppia maritima often share the same habitat, but R. maritima appears more resistant to environmental stress. We investigated the impact of light intensity and water column O-2 concentrations on radial oxygen loss (ROL), in young specimens of Z. marina and R. maritima. Planar optode imaging revealed that ROL of Z. marina was localized to the root tip, while R. maritima showed ROL along extensive root sections. The total root biomass of the 2 species was similar, but, while R. maritima had only 1 root, of which 33% of its length showed ROL, Z. marina had 2 to 5 individual roots, where only 2 to 3 exhibited O-2 leakage, but then only at root tips. ROL resulted in an oxic volume of 4.26 +/- 0.51 mm(3) plant(-1) for Z. marina and 5.39 +/- 0.47 mm(3) plant(-1) for R. maritima (n = 3). ROL per plant at light saturation was 2.32 +/- 0.30 and 2.89 +/- 0.38 nmol h(-1) for Z. marina and R. maritima, respectively. These values declined by 71 and 60% in darkness. However, both species were able to maintain ROL as long as ambient O-2 levels remained >50% air saturation. The calculated ROL integrated over a 24 h cycle was 48.8 +/- 10.6 nmol O-2 plant(-1) d(-1) (n = 3) for R. maritima and 30% less for Z. marina. The ability of R. maritima to maintain higher ROL than Z. marina could be an important feature defining its potential for colonizing and maintaining growth in eutrophic sediments.