School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire, LE12 5RD, UK.
Sci Rep. 2019 Feb 13;9(1):1983. doi: 10.1038/s41598-018-38093-2.
The growing population requires sustainable, environmentally-friendly crops. The plant growth-enhancing properties of algal extracts have suggested their use as biofertilisers. The mechanism(s) by which algal extracts affect plant growth are unknown. We examined the effects of extracts from the common green seaweed Ulva intestinalis on germination and root development in the model land plant Arabidopsis thaliana. Ulva extract concentrations above 0.1% inhibited Arabidopsis germination and root growth. Ulva extract <0.1% stimulated root growth. All concentrations of Ulva extract inhibited lateral root formation. An abscisic-acid-insensitive mutant, abi1, showed altered sensitivity to germination- and root growth-inhibition. Ethylene- and cytokinin-insensitive mutants were partly insensitive to germination-inhibition. This suggests that different mechanisms mediate each effect of Ulva extract on early Arabidopsis development and that multiple hormones contribute to germination-inhibition. Elemental analysis showed that Ulva contains high levels of Aluminium ions (Al). Ethylene and cytokinin have been suggested to function in Al-mediated root growth inhibition: our data suggest that if Ulva Al levels inhibit root growth, this is via a novel mechanism. We suggest algal extracts should be used cautiously as fertilisers, as the inhibitory effects on early development may outweigh any benefits if the concentration of extract is too high.
不断增长的人口需要可持续的、环保的作物。藻类提取物对植物生长的促进特性表明，它们可以用作生物肥料。藻类提取物影响植物生长的机制尚不清楚。我们研究了普通绿藻浒苔的提取物对模式陆地植物拟南芥萌发和根发育的影响。浓度高于 0.1%的浒苔提取物抑制拟南芥的萌发和根生长。浓度低于 0.1%的浒苔提取物刺激根生长。浒苔提取物的所有浓度均抑制侧根形成。赤霉素不敏感突变体 abi1 表现出对萌发和根生长抑制的敏感性改变。乙烯和细胞分裂素不敏感突变体部分对萌发抑制不敏感。这表明浒苔提取物对拟南芥早期发育的不同影响是由不同的机制介导的，并且多种激素参与了萌发抑制。元素分析表明，浒苔含有高水平的铝离子 (Al)。已经有人提出，乙烯和细胞分裂素在铝介导的根生长抑制中发挥作用：我们的数据表明，如果浒苔 Al 水平抑制根生长，那么这是通过一种新的机制。我们建议谨慎使用藻类提取物作为肥料，因为如果提取物的浓度过高，其对早期发育的抑制作用可能超过任何益处。
