Similar Growth Performance but Contrasting Biomass Allocation of Root-Flooded Terrestrial Plant Alternanthera philoxeroides (Mart.) Griseb. in Response to Nutrient Versus Dissolved Oxygen Stress
Similar Growth Performance but Contrasting Biomass Allocation of Root-Flooded Terrestrial Plant Alternanthera philoxeroides (Mart.) Griseb. in Response to Nutrient Versus Dissolved Oxygen Stress
复制标题
根部淹没的陆生植物空心莲子草 (Alternanthera philoxeroides (Mart.) Griseb) 的相似生长性能但对比生物量分配。
DOI：
10.3389/fpls.2019.00111
复制
发表时间：
2019-02-07
影响因子：
5.6
通讯作者：
Cornelissen, Johannes H. C.
中科院分区：
文献类型：
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作者：
Ayi, Qiaoli;Zeng, Bo;Cornelissen, Johannes H. C.
陆地植物在被淹没时可能会遭受营养和氧气压力，并且预计随着气候变化，洪水会增加。据报道，植物通常会改变生物量分配并产生更多的根以应对养分缺乏。然而，尚不清楚经历缺氧的植物是否会刺激根部的生物量分配以增强养分吸收，类似于经历养分缺乏的植物的行为。我们研究了陆生空心莲子草在根部淹水时对营养物与溶解氧缺乏的反应，包括植物生长、生物量分配、根系生产、根系效率（单位根表面积持续的植物生长）和根系通气组织形成。营养和溶解氧的缺乏都会阻碍根部淹没植物的生长。正如预期的那样，营养缺乏的植物增加了分配给根部的生物量，并表现出较低的根部效率；相比之下，经历溶解氧缺乏的植物减少了分配给根部的生物量，但获得了更高的根系效率。在经历溶解氧缺乏的植物中，根部通气组织通道的直径增大，但在经历营养缺乏的植物中没有变化。根部通气组织通道的拓宽可以改善含氧状态，从而提高根部在低氧环境下的养分吸收能力，这可能有利于植物耐受洪水。
Terrestrial plants may experience nutrient and oxygen stress when they are submerged, and increases in flooding are anticipated with climate change. It has been well reported that plants usually shift biomass allocation and produce more roots in response to nutrient deficiency. However, it is unclear whether plants experiencing oxygen deficiency stimulate biomass allocation to roots to enhance nutrient absorption, similar to how plants experiencing nutrient deficiency behave. We investigated the responses of the terrestrial species Alternanthera philoxeroides, upon root flooding, to nutrient versus dissolved oxygen deficiency in terms of plant growth, biomass allocation, root production, root efficiency (plant growth sustained per unit root surface area), and root aerenchyma formation. Both nutrient and dissolved oxygen deficiency hampered the growth of root-flooded plants. As expected, plants experiencing nutrient deficiency increased biomass allocation to roots and exhibited lower root efficiency; in contrast, plants experiencing dissolved oxygen deficiency decreased biomass allocation to roots but achieved higher root efficiency. The diameter of aerenchyma channels in roots were enlarged in plants experiencing dissolved oxygen deficiency but did not change in plants experiencing nutrient deficiency. The widening of aerenchyma channels in roots could have improved the oxygen status and thereby the nutrient absorption capability of roots in low oxygen environments, which might benefit the plants to tolerate flooding.