Galland William, Piola Florence, Mathieu Céline, Bouladra Lyna, Simon Laurent, Haichar Feth El Zahar
Université de Lyon, UMR 5557 LEM, Université Lyon 1, CNRS, INRA 1418, F-69622 Villeurbanne CEDEX, France.
Université de Lyon, UMR5023 LEHNA, Université Lyon 1, CNRS, ENTPE, F-69622 Villeurbanne CEDEX, France.
Microorganisms. 2020 Aug 7;8(8):1204. doi: 10.3390/microorganisms8081204.
Intensive agriculture uses a lot of nitrogen fertilizers to increase crop productivity. These crops are in competition with soil-denitrifying microorganisms that assimilate nitrogen in the form of nitrate and transform it into NO, a greenhouse gas, or N. However, certain plant species exude secondary metabolites, called procyanidins, which inhibit denitrifiers and increase the nitrate pool in the soil available for plant nutrition. This phenomenon is called biological denitrification inhibition. Previously, we showed that the addition of exogenous procyanidins to a lettuce crop induces denitrifier inhibition and increases nitrate content in the soil, affecting lettuce morphological traits. Here, the effects of procyanidin amendments in the field on a more long-term and nitrogen-consuming crop species such as celery were tested. The effects of procyanidin amendment on celery growth with those of conventional ammonium nitrate amendments were, therefore, compared. Denitrification activity, nitrate concentration, the abundance of denitrifying bacteria in the soil, and traits related to celery growth were measured. It was shown that the addition of procyanidins inhibits denitrifiers and increases the soil nitrate level, inducing an improvement in celery morphological traits. In addition, procyanidin amendment induces the lowest nitrogen concentration in tissues and reduces NO emissions.
集约化农业使用大量氮肥来提高作物产量。这些作物与土壤反硝化微生物存在竞争，反硝化微生物会吸收硝酸盐形式的氮并将其转化为一氧化氮（一种温室气体）或氮气。然而，某些植物物种会分泌次生代谢产物，即原花青素，它能抑制反硝化细菌并增加土壤中可供植物吸收的硝酸盐含量。这种现象被称为生物反硝化抑制。此前，我们发现向生菜作物中添加外源原花青素会抑制反硝化细菌并增加土壤中的硝酸盐含量，从而影响生菜的形态特征。在此，我们测试了在田间对芹菜这种更长期且耗氮的作物添加原花青素的效果。因此，比较了添加原花青素对芹菜生长的影响与传统硝酸铵添加的效果。测量了反硝化活性、硝酸盐浓度、土壤中反硝化细菌的丰度以及与芹菜生长相关的特征。结果表明，添加原花青素会抑制反硝化细菌并提高土壤硝酸盐水平，从而改善芹菜的形态特征。此外，添加原花青素会使组织中的氮浓度最低，并减少一氧化氮排放。
