Department of Crop Science, Faculty of Agriculture, Zagazig University, Zagazig, 44519, Egypt.
Department of Botany and Microbiology, Faculty of Science, Al-Azhar University, Cairo, 11884, Egypt.
Sci Rep. 2021 Dec 17;11(1):24142. doi: 10.1038/s41598-021-02847-2.
Water deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield-related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.
水分亏缺对豆科植物的生产有毁灭性的影响,特别是在干旱环境中当前突然的气候变化。应用植物促生根际细菌(PGPR)是生产天然氮和减轻干旱胁迫有害影响的有效方法。本研究调查了接种 PGPR 根瘤菌属(USDA 2435)和假单胞菌属(RA MTCC5279)单独或组合接种对在新开垦的贫瘠沙质土壤中,在充分供水(100%作物蒸散量[ETc])、中度干旱(75% ETc)和严重干旱(50% ETc)条件下,五种不同的蚕豆品种的生理生化和农艺性状的影响。干旱胁迫显著降低了光合色素和水分关系参数的表达。相比之下,与充分供水的植物相比,干旱胁迫下植物的抗氧化酶活性和渗透调节剂显著增加。干旱胁迫的这些不利影响降低了作物水分生产率(CWP)和与种子产量相关的性状。然而,PGPR 的应用,特别是两种菌株的联合体,改善了这些参数,并提高了种子产量和 CWP。评估的品种对干旱胁迫表现出不同的耐受性:Giza-843 和 Giza-716 在充分供水和中度干旱条件下具有最高的耐受性,而 Giza-843 和 Sakha-4 在严重干旱条件下更具有耐受性。因此,耐旱品种与 R. leguminosarum 和 P. putida 的共接种增强了它们在水分亏缺胁迫条件下的耐受性,并提高了它们的产量和 CWP。本研究首次表明,R. leguminosarum 和 P. putida 的联合使用是提高豆科作物抗旱性的一种有前途和生态友好的策略。