Departamento de Botánica, Ecología y Fisiología Vegetal, Grupo de Fisiología Molecular y Biotecnología de Plantas, Campus de Excelencia Internacional Agroalimentario, CEIA3, Campus de Rabanales, Edif. Severo Ochoa, Universidad de Córdoba, 14071 Córdoba, Spain.
Max-Planck-Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany.
J Exp Bot. 2023 May 19;74(10):3203-3219. doi: 10.1093/jxb/erad083.
Common bean (Phaseolus vulgaris L.), one of the most important legume crops, uses atmospheric nitrogen through symbiosis with soil rhizobia, reducing the need for nitrogen fertilization. However, this legume is particularly sensitive to drought conditions, prevalent in arid regions where this crop is cultured. Therefore, studying the response to drought is important to sustain crop productivity. We have used integrated transcriptomic and metabolomic analysis to understand the molecular responses to water deficit in a marker-class common bean accession cultivated under N2 fixation or fertilized with nitrate (NO3-). RNA-seq revealed more transcriptional changes in the plants fertilized with NO3- than in the N2-fixing plants. However, changes in N2-fixing plants were more associated with drought tolerance than in those fertilized with NO3-. N2-fixing plants accumulated more ureides in response to drought, and GC/MS and LC/MS analysis of primary and secondary metabolite profiles revealed that N2-fixing plants also had higher levels of abscisic acid, proline, raffinose, amino acids, sphingolipids, and triacylglycerols than those fertilized with NO3-. Moreover, plants grown under nitrogen fixation recovered from drought better than plants fertilized with NO3-. Altogether we show that common bean plants grown under symbiotic nitrogen fixation were more protected against drought than the plants fertilized with nitrate.
菜豆（Phaseolus vulgaris L.）是最重要的豆科作物之一，通过与土壤根瘤菌共生利用大气氮，减少对氮肥的需求。然而，这种豆类对干旱条件特别敏感，而干旱条件在种植这种作物的干旱地区很常见。因此，研究对干旱的响应对于维持作物生产力很重要。我们使用整合的转录组学和代谢组学分析来了解在 N2 固定或用硝酸盐（NO3-）施肥的标记类普通菜豆品系中对水分亏缺的分子响应。RNA-seq 显示，用 NO3-施肥的植物比 N2 固定植物的转录变化更多。然而，N2 固定植物的变化与耐旱性的关系比用 NO3-施肥的植物更为密切。N2 固定植物对干旱的反应积累了更多的尿囊素，而对初级和次级代谢物图谱的 GC/MS 和 LC/MS 分析表明，N2 固定植物的脱落酸、脯氨酸、棉子糖、氨基酸、鞘脂和三酰基甘油的水平也高于用 NO3-施肥的植物。此外，与用硝酸盐施肥的植物相比，在共生固氮条件下生长的植物从干旱中恢复得更好。总的来说，我们表明，与用硝酸盐施肥的植物相比，在共生固氮条件下生长的普通菜豆植物受到干旱的保护更好。
